Loading
Come for the art. Stay for the math.
Loading
Canonical labels, common aliases, and detailed descriptions for every mechanic type used in modern slot machines.
95 mechanics across 11 categories
Canonical labels, aliases, and descriptions for every mechanic type.
95 mechanics across 11 categories
Canonical labels, common aliases, and detailed descriptions for every mechanic type used in modern slot machines.
95 mechanics across 11 categories
10 mechanics
How the game determines what counts as a winning combination.
Lines / Winlines / Pay Lines / Fixed Lines / Active Lines
The game defines a fixed number of lines running across the reels. Matching symbols must land along one of these specific lines to form a win. The number of paylines is set by the game (10, 20, 50, etc.) and wins are evaluated left to right along each line.
All Ways / 243 Ways / 1024 Ways / Ways / All Ways Pay / Ways Pay
Matching symbols need to appear on consecutive reels starting from the left, in any row position. No fixed lines — if a matching symbol is anywhere on the next reel, it counts. Total ways = rows per reel multiplied together (e.g., 3×3×3×3×3 = 243 ways).
Big Time Gaming Megaways / BTG Megaways / Dynamic Ways / Hackways
A variable version of Ways to Win where each reel can display a different number of symbols on every spin (typically 2 to 7). The total ways to win changes every spin and can exceed 100,000+. Licensed from Big Time Gaming but widely adopted across providers.
Cluster Wins / Cluster / Grid Wins / Group Pays
Wins form when a group of identical symbols land touching each other horizontally or vertically, forming a cluster. No paylines or reels required — works on a grid. Minimum cluster size is usually 5+ symbols. Larger clusters pay more.
Scatter Win / Anywhere Pays / Count Pays
Symbols pay based on how many appear anywhere on the grid, regardless of position or adjacency. If enough matching symbols land on screen (typically 8+), you get paid. No lines, no clusters — just a symbol count across the entire grid.
Not Scatter Trigger — Scatter Pays is a win mechanic where scatter symbols pay based on count anywhere on the grid. Scatter Trigger is a bonus activation mechanic that opens a feature like free spins. One symbol can serve both roles.
Touching Pays / Neighbour Pays / Connected Pays
Symbols must be directly next to each other (horizontally or vertically) to form a win. Similar to cluster pays but with looser structural requirements — the shape of the group matters less than the adjacency chain.
Any Position Pays / Anywhere Wins / All Position Pays
Matching symbols anywhere on the reels count toward a win with no adjacency, sequence, or line requirement. Land enough of the same symbol in any positions, and you're paid. The loosest possible win evaluation.
Both Ways / Bidirectional Pays / Left and Right / Pay Both Ways / Win Either Way
Modifies any line-based or ways system to evaluate wins from right to left as well as the standard left to right. Effectively doubles the number of winning opportunities on every spin without changing the grid or bet.
Split Grid Ways / Dual Ways / Divided Ways
The reel grid is divided into separate sections, each generating their own independent ways to win. Those sections can then combine or interact under certain conditions, creating enormous win potential when both halves align.
Not Dual Grid — Split Ways divides one grid into sections generating independent ways that can combine. Dual Grid is two separate grids with their own mechanics.
Prize Drop / Instant Prize / Instant Payout / Random Prize / Cash Drop
A random cash award that triggers independently of any symbol combination, feature, or bonus. The game simply awards a prize — no clusters, no lines, no triggers required. Can happen on any spin.
14 mechanics
How the reels themselves behave — their structure, movement, reactions to wins, and transformations.
Tumbles / Cascades / Avalanche / Tumbling Reels / Collapsing Reels / Gravity Reels / Rolling Reels / Falling Symbols / Symbol Drop
When a win forms, the winning symbols are removed from the grid and new symbols fall/drop into the empty spaces from above. If the new arrangement creates another win, it cascades again. The chain continues until no new wins form — all on a single bet.
Growing Reels / Reel Expansion / Grid Expansion Static / Extra Rows
Additional rows are added to the grid during specific conditions — usually when entering a bonus round. A game that normally plays on 5×3 might expand to 5×6 for the duration of a feature, increasing ways to win and changing the math model.
Not Dynamic Grid Expansion — Expanding Reels set a larger grid at the start of a feature and it stays fixed. Dynamic Grid Expansion grows the grid incrementally mid-feature as wins cascade.
Progressive Grid / Collapsing Mine / Growing Grid / Unlocking Rows / Row Unlock
The grid physically grows mid-feature as wins form, progressively unlocking new rows or columns with each cascade or win event. Unlike static Expanding Reels (which add rows at feature start), this is gradual — the grid grows bigger the longer your win chain continues.
Not Expanding Reels — Dynamic Grid Expansion grows the grid progressively during gameplay with each win/cascade. Expanding Reels set the grid size once at feature start.
Respins / Extra Spin / Bonus Spin / Respin Feature
One or more free extra spins awarded by the game after specific events — landing certain symbols, near-miss combinations, or improving win conditions. A small second chance mechanic triggered automatically, not purchased by the player.
Not Buy Respin — Re-Spins are free extra spins triggered by gameplay. Buy Respin is a paid respin of individual reels chosen by the player.
Hold and Spin / Hold & Spin / Lock and Respin / Sticky Respin / Cash Respin / Money Respin
Qualifying symbols (often coins or special icons) lock in place while all remaining positions respin. If new qualifying symbols land, they lock too and respins reset (usually to 3). Continues until no new symbols appear or all positions are filled. A self-contained bonus loop.
Not Locking Reels — Hold & Respin locks individual qualifying symbols in place while all other positions respin. Locking Reels freezes entire reels.
Nudge Reels / Reel Nudge / Symbol Nudge / Nudge Up / Nudge Down / xNudge
After a spin lands, one or more reels shift up or down by one or more positions to create or improve a win. Can be random, triggered by near-misses, or guaranteed for specific symbol types (e.g., stacked wilds that always nudge fully into view, gaining a +1 multiplier per nudge step).
Synced Reels / Twin Reels / Synchronized Reels / Cloned Reels / Paired Reels / Mirror Reels / Dual Reel Sync
Two or more reels spin with identical symbol strips, guaranteeing matching columns. Which reels are linked can be random each spin or fixed. Creates large multi-reel matches that would be statistically rare otherwise.
Not Locking Reels — Linked Reels sync two or more reels to show identical symbol strips. Locking Reels freeze a reel result across multiple spins.
Infinite Reels / Endless Reels / Adding Reels
The grid starts at a fixed width and adds a new reel to the right each time a winning symbol appears on the rightmost reel. Theoretically, reels can keep adding indefinitely as long as wins keep extending. The grid grows horizontally with each successive win.
Giant Reels / Dual Reel Set / Main and Colossal
A second, larger reel set plays alongside the main grid. The colossal set typically mirrors some symbols from the main set or shares wilds between the two. Wins are evaluated on both grids, and interactions between them create unique bonus potential.
Not Colossal Symbols — Colossal Reels is a second, larger reel set alongside the main grid that mirrors or interacts with it. Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on a single grid.
Split Screen / Twin Grid / Double Grid Play / Parallel Grids / Multi Grid
Two separate grids play simultaneously, each with their own independent mechanics. The grids can interact by sharing wilds, combining multipliers, transferring symbols, or merging results. Distinct from Colossal Reels — both grids operate independently rather than one mirroring the other.
Not Colossal Reels or Split Ways — Dual Grid runs two fully independent grids that cross-pollinate (sharing wilds, combining multipliers). Colossal Reels mirrors one grid onto a larger one. Split Ways divides a single grid into sections for separate ways calculations.
Swap Reels / Reel Exchange / Reel Shuffle
Entire reel strips get exchanged between positions after the spin lands. Reel 1 might swap with Reel 5, or multiple reels shuffle simultaneously. Rearranges the grid layout to create new winning combinations from the same set of landed symbols.
Locked Reels / Reel Lock / Frozen Reels / Held Reels / Sticky Reels
Entire reels freeze in place for one or more subsequent spins while the remaining reels continue to spin normally. Distinct from Hold & Respin (locks individual symbols) and Linked Reels (syncs strips). The locked reel keeps its exact result across multiple spins.
Not Linked Reels or Hold & Respin — Locking Reels freeze entire reels for subsequent spins. Linked Reels force reels to show identical strips. Hold & Respin locks individual symbols (not entire reels).
Modifier Reel / Auxiliary Reel / Extra Reel / Bonus Reel / Hot Sauce Reel / Conveyor Reel
A separate reel strip outside the main grid that spins independently to deliver modifiers — extra wilds, multipliers, bombs, split symbols, or other effects. Does not participate in win formation directly. Acts as a randomized modifier delivery system for the main grid.
Not Colossal Reels — Side Reel is an auxiliary strip that delivers modifiers to the main grid (it does not generate wins itself). Colossal Reels is a second full reel set that generates its own wins.
Reel Respin / Paid Respin / Respin Purchase / Individual Reel Respin
The player pays a cost to respin one or more specific reels while keeping the rest of the grid locked. The cost is usually calculated based on the potential improvement. Distinct from Re-Spins (free, auto-triggered) and Feature Buy (purchases the full bonus).
Not Re-Spins — Buy Respin is a player-paid respin of specific individual reels. Re-Spins are free extra spins awarded by the game.
14 mechanics
Wild symbol variants and behaviors. Wilds substitute for other symbols to complete wins, but modern games have created an entire family of specialized wild types.
Wild Symbol / Standard Wild / Basic Wild / Substitute
The basic wild symbol substitutes for any regular paying symbol to help complete winning combinations. Typically does not substitute for scatters, bonus symbols, or other special symbols. The foundation that all other wild variants build upon.
Growing Wilds / Full Reel Wild / Stretching Wild
When this wild lands, it stretches to cover the entire reel (vertically) or the entire row (horizontally). One wild symbol becomes a full column or row of wilds, dramatically increasing substitution coverage across multiple paylines or ways.
Stacked Wild Symbols / Wild Stacks / Full Stack Wild
Multiple wild symbols appear stacked on top of each other on a single reel as part of the reel strip. When a full stack lands in view, it covers the entire reel. Unlike Expanding Wilds (one symbol stretches), stacked wilds are multiple individual wilds occupying consecutive positions.
Not Stacked Symbols — Stacked Wilds are wild substitutes arranged in a stack. Stacked Symbols are regular paying symbols in stacks; they do not substitute.
Locked Wilds / Persistent Wilds / Frozen Wilds / Held Wilds
Wild symbols that remain locked in their grid position for one or more subsequent spins. Especially impactful during free spins where they accumulate over time, gradually filling the grid with wilds as the feature progresses.
Shifting Wilds / Moving Wilds Directional / Wandering Wilds
Wild symbols move one position in a fixed direction (typically left) with each spin, remaining on the grid until they walk off the edge. Each step is essentially a free respin with the wild in a new position. Moves in a predictable, consistent direction.
Not Roaming, Jumping, or Trailing Wilds — Walking Wilds move one step in a fixed direction (usually left) per spin. Roaming Wilds move unpredictably to adjacent positions. Jumping Wilds teleport anywhere. Trailing Wilds leave copies behind.
Wild Trail / Shadow Wilds / Echo Wilds / Copy Wilds
A wild that leaves behind a copy of itself in its previous position as it moves across the grid. Combines the movement of Walking Wilds with duplication — the trail grows longer as the wild walks, creating multiple wilds from a single source.
Not Walking Wilds — Trailing Wilds move AND leave a wild copy behind in their previous position. Walking Wilds vacate their old position when they move.
Moving Wilds / Drifting Wilds / Floating Wilds
Wild symbols that move in unpredictable directions between spins — up, down, left, right, or diagonally. Unlike Walking Wilds (fixed direction), roaming wilds can go anywhere adjacent. Adds randomness to where wild coverage will appear next.
Not Walking or Jumping Wilds — Roaming Wilds move to adjacent positions in unpredictable directions. Walking Wilds follow a fixed direction. Jumping Wilds teleport to any random position.
Teleporting Wilds / Bouncing Wilds / Leaping Wilds / Random Position Wilds
Wild symbols that teleport to a completely random grid position on each spin, carrying a persistent multiplier that can grow over the course of a feature. Distinct from Walking/Roaming (which move to adjacent positions) — jumping wilds can land anywhere on the grid regardless of previous position.
Not Walking or Roaming Wilds — Jumping Wilds teleport to any random grid position each spin. Walking Wilds step one position in a fixed direction. Roaming Wilds drift to adjacent positions.
Added Wilds / Dropped Wilds / Wild Placement
The game places wild symbols onto random grid positions after the spin has landed. The wilds were not part of the original spin result — they are injected by the game engine. Might add 2, 3, 5 or more wilds to turn a losing spin into a winner.
Not Infectious Wilds — Random Wilds place wilds at random positions regardless of grid content. Infectious Wilds select a symbol type and convert all instances of it into wilds (spread is content-dependent).
Spreading Wilds / Virus Wilds / Contagious Wilds / Wild Infection
A wild that selects a random regular symbol type and converts every instance of that symbol on the grid into a wild. The infection spreads based on what's already on the reels. Multiple infectious wilds can each target different symbols, potentially turning large portions of the grid wild.
Not Random Wilds — Infectious Wilds choose a symbol type on the grid and convert every instance into wilds. Random Wilds place wilds at random positions without regard to existing symbols.
Exploding Wilds / xBomb / Destruction Wilds / Blast Wilds / Detonating Wilds / Wild Blast
A wild symbol that detonates when it participates in a win (or on landing), removing all adjacent symbols from the grid. Often carries or adds a persistent multiplier that increases with each explosion. The cleared positions allow new symbols to cascade in. Combines wild substitution with symbol destruction and multiplier accumulation.
Not Remove Symbols — Bomb Wilds are wild symbols that explode, removing adjacent symbols with an active event and often a growing multiplier. Remove Symbols is a passive feature that strips specific symbol types without explosion or multiplier.
Multiplying Wilds / Wild Multiplier / x2 Wild / x3 Wild
Wild symbols that substitute like a normal wild AND multiply the value of any win they participate in — by 2×, 3×, 5× or more. When multiple multiplier wilds contribute to the same win, their multipliers typically multiply together (e.g., 2× and 3× = 6×).
Not Multiplier Symbols — Multiplier Wilds substitute for other symbols AND carry a multiplier. Multiplier Symbols are their own symbol type with a multiplier but do not substitute.
Full Wild Reel / Entire Reel Wild / Wild Column
An entire reel turns completely wild, either randomly or as part of a feature trigger. Every position on that reel becomes a wild symbol, guaranteeing substitution on every payline or way passing through it. Can affect one or multiple reels.
Wild Overlay / Superimposed Wilds / Layered Wilds
Wild symbols placed on top of existing symbols without replacing the underlying reel result. The wild acts as a transparent layer — if the wild is removed or expires, the original symbol underneath is still there. Used in mechanics where wilds are temporary additions rather than replacements.
6 mechanics
Mechanics that scale win values by a factor. Can apply to individual wins, entire spins, specific grid positions, or accumulate over time.
Multiplier / Payout Multiplier / Win Boost
A specific multiplier applied to an individual win after it has been calculated. A 50-coin win with a 3× win multiplier pays 150 coins. Applied per winning combination, not globally.
Total Multiplier / Round Multiplier / Feature Multiplier / Base Multiplier
A multiplier that applies to all wins on all spins while it is active. Commonly used during free spins rounds and often increases as the round progresses. Everything pays more while this is in effect.
Column Multiplier / Reel Boost
A multiplier attached to a specific reel (column). Any win that includes a symbol from that reel gets boosted by the multiplier value displayed on it. Different reels can carry different multiplier values.
Not Position Multiplier — Reel Multiplier applies to an entire column. Position Multiplier applies to a specific individual cell. Reel multiplier boosts everything on that reel; position multiplier boosts only the specific grid square.
Cell Multiplier / Grid Multiplier / Spot Multiplier / Tile Multiplier / Square Multiplier
Multipliers tied to specific grid cells rather than reels or wins. Individual squares on the grid display a multiplier value, and any winning symbol occupying that cell gets its contribution boosted. Multipliers on cells typically accumulate across cascades — each new win on that cell increases its multiplier. Central to tumble games like Sugar Rush and Sweet Bonanza 1000.
Not Reel Multiplier — Position Multiplier is tied to a specific grid cell that can accumulate its own value. Reel Multiplier applies to an entire column uniformly.
Ramping Multiplier / Increasing Multiplier / Escalating Multiplier / Cascade Multiplier / Tumble Multiplier
A multiplier that increases over time or with each consecutive win event. In cascading reels games, it typically starts at 1× and goes up by 1 with each cascade: 1×, 2×, 3×, 4×, etc. Resets when the cascade chain ends or the feature concludes. Rewards long win chains.
Not Progressive Jackpot — Progressive Multiplier increases during a feature (e.g., +1× per cascade) and resets after. Progressive Jackpot is a prize pool that grows with bets over time. Unrelated mechanics.
Bet Multiplier / Enhanced Bet / Boosted Bet / Super Bet / xBet
An optional surcharge on top of the base bet (typically 10–100% extra) that unlocks a specific in-game advantage — better odds, enhanced features, or additional mechanics. The player pays more per spin voluntarily in exchange for improved conditions.
13 mechanics
Discrete events and game modes that break up the base game — bonus rounds, free spins, interactive features, and triggered events.
FS / Free Games / Bonus Spins / Feature Spins / Bonus Round
A set number of spins awarded at no cost, usually triggered by landing scatter symbols. Free spins rounds often come with enhanced mechanics — higher multipliers, more wilds, expanded reels, or special rules that don't apply in the base game. The primary source of big wins in most slots.
Retrigger / Extra Spins / Bonus Retrigger / Add Spins
The ability to earn additional free spins while already inside a free spins round. Land the trigger symbols again during the bonus and more spins get added to your total. Some games allow multiple retriggers, extending the round far beyond its initial length.
Buy Feature / Bonus Buy / Buy Bonus / Direct Buy / Feature Purchase
Pay a lump sum (typically 50× to 100× the base bet) to skip the base game entirely and jump straight into the bonus feature. Controversial, banned in some jurisdictions (UK, Belgium), and beloved by impatient players. The standard single-tier buy option.
Not Tiered Feature Buy or Lucky Buy — Feature Buy is a single fixed-price purchase to enter the bonus. Tiered Feature Buy offers multiple price points for different bonus levels. Lucky Buy randomizes the bonus level at a discount.
Pick & Click / Pick Me / Choose Feature / Selection Bonus / Pick and Win
Presents the player with a set of hidden items — chests, doors, envelopes — and asks them to choose. Each pick reveals a prize: coins, multipliers, extra spins, or upgrades. Outcomes are predetermined by the RNG, but the interaction creates a sense of agency.
Spin the Wheel / Bonus Wheel / Prize Wheel / Fortune Wheel / Wheel of Fortune
A large spinning wheel appears on screen with different prizes in each segment. The player spins the wheel and collects whatever it lands on — coins, multipliers, jackpot tiers, or feature upgrades. Visually dramatic and common on land-based cabinets.
Mystery Bonus / Random Bonus / Surprise Feature / Random Modifier
A feature that can trigger at any time during the base game without warning or specific symbol requirements. Might add wilds, transform symbols, award instant wins, or activate a full bonus round. The unpredictability and surprise element is the core appeal.
Not Mystery Symbols — Mystery Feature is a random bonus event that can do anything (add wilds, trigger free spins, award prizes). Mystery Symbols are a specific symbol type where all instances reveal the same randomly chosen symbol.
Random Trigger / Random Activation / Random Event
Any bonus or enhancement that activates randomly rather than through a specific symbol combination. Distinct from Mystery Feature (which is a single surprise event) — this is the broader category of any randomly-triggered mechanic.
Upgrade Feature / Feature Upgrade / Level Select / Bonus Choice / Pre-Bonus Selection
The ability to improve or choose your bonus configuration before or during the round. Some games offer a choice between different bonus tiers, or let you upgrade through gameplay — accepting fewer spins with more powerful mechanics.
Not Buy Enhancement — Bonus Upgrade is earned or chosen during gameplay to improve a bonus. Buy Enhancement is a paid purchase made before the bonus starts.
Double or Nothing / Risk Feature / Card Gamble / Coin Flip / 50/50 Gamble
Appears after a win and lets the player risk their winnings on a double-or-nothing bet — typically a coin flip or card-color guess. Win and the payout doubles, lose and it's gone. Some games allow multiple rounds.
Not Max Win Gamble — Gamble Feature is offered after any win for a 50/50 double-or-nothing. Max Win Gamble only triggers when near the game maximum win cap.
xBizarre / Endgame Gamble / Cap Gamble / Max Win Chance
A special gamble offered specifically when the player is near the game's maximum win cap after a bonus round. Each gamble gives a 50/50 chance to add another chunk toward the max win. Distinct from regular Gamble Feature — only available at extreme win levels and interacts with the max win ceiling.
Not Gamble Feature — Max Win Gamble is a special opportunity near the max win cap. Standard Gamble Feature is offered after any win.
Scatter Bonus Trigger / Scatter Activation / Bonus Scatter / Trigger Scatter
Scatter symbols that specifically serve as bonus activation triggers — landing 3+ scatters opens a feature like free spins. Distinct from Scatter Pays (where scatters pay based on count). The same scatter can do both in one game.
Not Scatter Pays — Scatter Trigger opens a bonus feature when enough scatters land. Scatter Pays awards a payout based on scatter count. The same symbol can do both in a single game.
Board Game Bonus / Path Bonus / Map Bonus / Journey Bonus / Trail Feature / Board Walk
A board-game-style bonus where the player advances along a trail or path, landing on spaces that award prizes, multipliers, extra moves, or feature triggers. Classic land-based cabinet mechanic experiencing a revival.
Continue Feature / Buy Extra Spin / Extend Bonus / Add Spin / Spin Extension
After a bonus round ends, the game offers to sell additional spins at a price calculated from the current bonus state (active multipliers, sticky wilds, grid conditions). Extends a completed bonus while preserving its accumulated state. Not a Feature Buy (pre-bonus) or Buy Respin (individual reel).
Not Feature Buy or Buy Respin — Extra Spin Purchase extends an active bonus round that has already been playing, priced on the current bonus state. Feature Buy skips the base game to enter a bonus. Buy Respin targets individual reels.
4 mechanics
Purchasable mechanics that let players pay to alter game conditions, trigger features, or enhance upcoming bonuses.
Multi-Level Buy / Tiered Bonus Buy / Multiple Buy Options / Bonus Tiers Buy
Multiple buy-in price points for different bonus levels. For example: 60× for basic free spins, 100× for enhanced, 500× for super. Each tier costs more but provides a more powerful bonus with better mechanics or more starting wilds.
Not Feature Buy — Tiered Feature Buy offers multiple price tiers (cheap to expensive) with different bonus levels. Standard Feature Buy has one fixed price and one bonus level.
Random Buy / Mystery Buy / Lucky Draw / Discount Buy / Gamble Buy
A discounted feature buy where the player pays a reduced price but receives a random bonus tier. Might get the basic bonus or the premium one — it's a gamble. Cheaper than buying the top tier directly, but you can't choose what you get.
Not Feature Buy — Lucky Buy is a discounted purchase where the bonus level is randomized. Standard Feature Buy has a fixed price and guaranteed bonus level.
Extra Scatter / Scatter Buy / Scatter Guarantee / Nolimit Booster / Add Scatter
Pay to add one or more extra scatter symbols to the next spin, improving trigger odds without guaranteeing it. You still need the remaining scatters to land naturally. Different from Ante Bet (which modifies odds passively every spin).
Not Ante Bet, Double Chance, or Bonus Chance — Buy Scatter adds extra scatters to one specific spin only. Ante Bet is a persistent per-spin surcharge. Double Chance doubles scatter rates persistently. Bonus Chance adjusts trigger conditions.
Buy Upgrade / Enhanced Buy / Pre-Loaded Buy / Boosted Start
Pay a premium to start a bonus round with pre-loaded upgrades — a starting multiplier of 3× instead of 1×, sticky wilds already placed, or enhanced grid conditions. The bonus triggers normally or via standard buy, but you're paying for a head start.
Not Bonus Upgrade — Buy Enhancement is a paid pre-purchase that boosts starting conditions of a bonus. Bonus Upgrade happens during or at the start of a bonus through gameplay or a choice mechanic (earned, not bought).
4 mechanics
Mechanics that create forward momentum — accumulation, leveling, and persistent advancement across spins or sessions.
Meter / Fill Meter / Progress Bar / Charge Meter / Feature Meter / Energy Bar
A visual meter that fills gradually as specific symbols land or events occur. When full, it triggers a bonus, modifier, or reward. Gives every spin a sense of progress. Resets after triggering.
Levels / Level Up / Multi-Level Bonus / Staged Bonus / Bonus Levels / Feature Progression
A bonus with multiple escalating levels, each more rewarding than the last. Advancement depends on performance, trigger symbols, or accumulated progress. Higher tiers unlock better multipliers, more powerful mechanics, or reduced symbol sets.
Symbol Collection / Collector / Gather Feature / Accumulate Symbols
Special symbols that land on the reels and activate values, wilds, or enhancements that have been building in specific grid positions. They act as activators — they don't do much alone, but they unlock value accumulated elsewhere.
Not Value Collect — Collect Symbols gather enhancements (wilds, upgrades, abstract bonuses) from grid positions. Value Collect specifically aggregates monetary values from coin/cash symbols into a single payout.
Persistent Collection / Cross-Session Progress / Permanent Upgrades / Lifetime Collection / Save Progress
Progress that carries over between bonus rounds or play sessions. Collections that take dozens of spins to complete, permanent upgrades that unlock over time, or cumulative achievements. Creates long-term player investment in a specific game.
8 mechanics
Mechanics built around symbols that carry specific monetary values rather than paying through traditional combinations.
Coins / Money Symbols / Gold Symbols / Token Symbols
Symbols displaying a specific value (coins, tokens). Their payout typically only activates during Hold & Respin features or bonus rounds — in the base game they may land but don't pay until collected by a feature.
Not Prize Symbols — Coin Symbols typically only pay during Hold & Respin or collection features. Prize Symbols pay on landing during normal base game spins. Value Symbols is the umbrella term for all.
Cash / Money Bags / Dollar Symbols / Bet Multiplier Symbols
Symbols displaying their value as a direct cash amount or bet multiplier. Functionally similar to Coin Symbols — the distinction is mostly thematic. Some games activate them only in features; others pay on landing.
Not Prize Symbols — Cash Symbols function like Coin Symbols but with different thematic presentation and value ranges. They typically pay during features, not in the base game.
Symbol Values / Numbered Symbols / Valued Symbols
The umbrella term for any symbol carrying a displayed numerical value — coins, gems, tokens, orbs. Used as a generic label covering all value-carrying symbol types regardless of visual presentation.
Umbrella term covering Coin Symbols, Cash Symbols, and Prize Symbols. Use this when the specific variant does not matter or is unclear.
Instant Pay Symbols / Direct Pay / Base Game Pay Symbols / Instant Value
Symbols that award their displayed cash value immediately on landing during the base game, without needing a feature. Distinct from Coin/Cash Symbols which typically only pay within bonus contexts. These pay on sight.
Not Coin Symbols or Cash Symbols — Prize Symbols pay their displayed value immediately on landing in the base game. Coin/Cash Symbols only pay during Hold & Respin or similar features.
Sack / Bag Symbol / Collector Coin / Value Sweep / Cash Collector / Payer Symbol
Symbols that sweep up all coin/cash values currently visible on the grid into a single combined payout. When a collector lands, it sums every value symbol on screen and pays the total. Central to Hold & Respin and coin features. Distinct from Collect (Symbols) which activates enhancements — this aggregates monetary values.
Not Collect (Symbols) — Value Collect sweeps up monetary values from coin/cash symbols into a payout. Collect Symbols gather non-monetary enhancements like wilds and upgrades.
Boost Values / Value Multiplier / Coin Boost
A feature that increases the values on all coin/value symbols currently on the grid. Might double every value, add a flat amount, or multiply by a random factor. Applied to existing symbols, not new ones.
Rising Values / Incrementing Values / Value Growth / Tick Up
Values on coin/value symbols increase incrementally with each game event — each spin, cascade, or respin. Values tick up gradually rather than receiving a one-time boost. Rewards patience and long feature runs.
Combine Values / Merge Coins / Value Combine / Symbol Merge / Coin Merge
Multiple value symbols physically combine into a single, larger symbol carrying the total of merged values. Two coins worth 2× and 3× become one worth 5×. Often paired with Hold & Respin where symbols can move and merge on the grid.
6 mechanics
The biggest possible payouts — fixed prizes, growing pools, and multi-tier jackpot systems.
Static Jackpot / Set Jackpot / Flat Jackpot / Non-Progressive Jackpot
Pays a predetermined, unchanging amount. The value is set by the game and stays constant regardless of play volume or time since the last hit.
Growing Jackpot / Pooled Jackpot / Accumulating Jackpot
Grows over time as a percentage of every bet feeds into the pool. Keeps climbing until won, then resets to a seed amount. Can be local (one game) or networked (many games/casinos). Can reach life-changing sums.
Not Progressive (Ramping) Multiplier — Progressive Jackpot is a prize pool that grows with every bet placed. Progressive Multiplier is a multiplier that ramps up during a feature (e.g., +1× per cascade). Unrelated mechanics sharing the word "progressive".
MHB Jackpot / Must Drop Jackpot / Guaranteed Jackpot / Drop By Jackpot / Must Go Jackpot
A progressive jackpot with a visible ceiling. Guaranteed to be won before reaching a specific amount. As the value approaches the ceiling, trigger probability increases. Creates a dynamic where players seek machines near the must-hit-by value.
Mini/Minor/Major/Grand / Jackpot Levels / Multi-Tier Jackpot / Bronze/Silver/Gold/Platinum / Tiered Jackpot
Multiple jackpot levels organized by size — commonly Mini, Minor, Major, Grand. Each tier has different value and odds. The smallest triggers frequently; the largest is rare but substantial.
Jackpot Spinner / Jackpot Prize Wheel / Tier Wheel
A dedicated wheel-spin event that determines which jackpot tier the player wins. The segment it lands on determines the prize — from smallest tier to grand jackpot.
Linked Jackpot / Wide Area Progressive / WAP / Network Jackpot / Cross-Game Jackpot / Shared Jackpot
A shared jackpot pool spanning multiple different game titles and potentially multiple casinos. Bets from all linked games feed the same pool, creating much larger jackpots than any single game could generate alone.
4 mechanics
Optional mechanics activated by the player that change the risk profile in exchange for better potential rewards.
Enhanced Bet / Boosted Spin / Super Stake / Feature Bet
An ongoing surcharge (typically 20–25% extra) in exchange for persistently improved odds of triggering the bonus. Active on every spin until the player turns it off.
Not Buy Scatter — Ante Bet is a persistent per-spin surcharge (20-25% extra) for better bonus odds. Buy Scatter is a one-time payment to add scatters to a single spin.
Extra Chance / 2x Chance / Scatter Boost
Specifically doubles the probability of one particular event — usually scatter appearance or bonus triggers. A targeted probability modifier.
Not Ante Bet — Double Chance specifically doubles scatter/trigger symbol probability. Ante Bet is a general surcharge for improved bonus odds.
Bonus Boost / Trigger Boost / Feature Chance
Increases the likelihood of entering the bonus round through a general mechanism — enhancing scatter symbols, changing trigger conditions, or lowering thresholds.
Not Ante Bet or Double Chance — Bonus Chance modifies trigger conditions or math model, which may differ from simply doubling scatter rates or adding a bet surcharge.
Bonus Guarantee / Forced Trigger / Auto Trigger / Guaranteed Feature
After paying a premium, the bonus is guaranteed to trigger within a set number of spins. If it doesn't trigger naturally, the game forces it. Bridges standard play and Feature Buy.
12 mechanics
Mechanics that change the symbols on the reels after landing — transforming, upgrading, splitting, adding, removing, or restructuring them.
Low to High / Symbol Promotion / Pay Upgrade / Symbol Ascend
Low-value symbols convert into higher-value ones. Common implementation: all instances of the lowest-paying symbol become the next tier up, compressing the paytable. Can chain through multiple tiers.
Transforming Symbols / Symbol Change / Symbol Morph / Symbol Convert
One symbol type changes into another. Turning a random regular symbol into a wild, or converting all of one type into a different matching type. Targeted — you know what becomes what.
Not Symbol Infection — Symbol Transform is a targeted change of one symbol type into another. Symbol Infection spreads from a source to adjacent positions in a chain reaction.
Spreading Symbols / Infectious Symbols / Symbol Spread / Contagious Symbols / Symbol Propagation / Infectious xWays
Non-wild symbols spread to adjacent positions, converting neighbours into copies of themselves. Propagates outward from the source. Distinct from Symbol Transform (random/targeted) — infection spreads organically from a point of origin.
Not Symbol Transform — Symbol Infection spreads organically from a source, converting adjacent or matching neighbours into copies. Symbol Transform is a targeted or random change of one type into another without spatial propagation.
Swap Symbols / Symbol Exchange / Symbol Switch
Two symbol types exchange — all hearts become stars and all stars become hearts. A lateral swap that can suddenly create winning combinations where none existed.
Split Symbols / xSplit / Splitting Symbols / Symbol Divide / Razor Split
A symbol or modifier splits all symbols in its row or reel into two, doubling their count and the ways to win through that position. The split symbol itself often becomes a wild. If split multiple times, symbols display a multiplier. Pioneered by Nolimit City's xSplit mechanic.
Symbol Inject / Symbol Drop / Extra Symbols / Bonus Symbols / Symbol Placement
Additional symbols placed onto the grid that weren't part of the original spin. The game drops extra wilds, scatters, or high-value symbols after the reels stop.
Symbol Removal / Symbol Clear / Symbol Destroy / Strip Symbols / Cosmic Sweep
Certain symbols are stripped off the grid entirely. Removes low-value or non-winning symbols to increase the concentration of winning symbols. Often paired with cascading reels where removed symbols create space for new ones.
Not Bomb Wilds — Remove Symbols passively strips specific symbol types from the grid. Bomb Wilds are wild symbols that actively explode adjacent symbols and typically carry a growing multiplier.
Mystery Stack / Secret Symbols / Unknown Symbols / ? Symbols / Reveal Symbols / xWays
Special placeholder symbols that all simultaneously reveal as the same randomly chosen regular symbol. Every mystery symbol on the grid reveals identically. Creates large groups of matching symbols from uncertain positions. The basis of Nolimit City's xWays mechanic.
Not Mystery Feature — Mystery Symbols are placeholder symbols that all reveal the same random symbol simultaneously. Mystery Feature is a random bonus event that could trigger any kind of enhancement.
Mega Symbols / Giant Symbols / Oversized Symbols / Big Symbols / 2x2 Symbols / 3x3 Symbols / Super Symbols
Oversized symbols occupying multiple grid positions (2×2, 3×3, or larger). Each cell they occupy counts as a separate instance, dramatically increasing win potential across multiple paylines or ways.
Not Colossal Reels — Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on one grid. Colossal Reels is a second full reel set that mirrors or interacts with the main grid.
Full Stacks / Symbol Stacks / Stacked Regulars / Full Reel Symbol
Non-wild regular symbols appearing in full stacks covering an entire reel. When a full stack lands in view, that reel shows only one symbol type, creating strong multi-payline wins. The non-wild counterpart to Stacked Wilds.
Not Stacked Wilds — Stacked Symbols are regular paying symbols in full stacks. Stacked Wilds are wild substitutes in stacks that can substitute for other symbols.
Multiplier Values / Symbol Multipliers / Multiplier Icons / Multiplier Positions
Non-wild symbols carrying a multiplier value. When they participate in a win or occupy specific positions, they multiply the payout. Often accumulate or double during tumble/cascade sequences. Distinct from Multiplier Wilds.
Not Multiplier Wilds — Multiplier Symbols are non-wild symbols that carry a multiplier value. Multiplier Wilds both substitute and multiply.
Locked Cells / Extra Cells / Bonus Cells / Hidden Positions / Enhancer Positions / Modifier Cells
Extra grid positions above, below, or beside the main reel area that start locked. They unlock when specific conditions are met (wilds landing, scatters appearing, bonus activation) and reveal special symbols — wilds, multipliers, mystery symbols, xWays, or split modifiers. They expand the effective grid when active and inject modifiers. Pioneered by Nolimit City, now widely adopted.
Not Expanding Reels — Enhancer Cells are hidden positions that unlock conditionally to reveal modifiers (wilds, multipliers, splits). Expanding Reels add standard rows with regular symbols at feature start.
10 mechanics
How the game determines what counts as a winning combination.
Lines / Winlines / Pay Lines / Fixed Lines / Active Lines
The game defines a fixed number of lines running across the reels. Matching symbols must land along one of these specific lines to form a win. The number of paylines is set by the game (10, 20, 50, etc.) and wins are evaluated left to right along each line.
All Ways / 243 Ways / 1024 Ways / Ways / All Ways Pay / Ways Pay
Matching symbols need to appear on consecutive reels starting from the left, in any row position. No fixed lines — if a matching symbol is anywhere on the next reel, it counts. Total ways = rows per reel multiplied together (e.g., 3×3×3×3×3 = 243 ways).
Big Time Gaming Megaways / BTG Megaways / Dynamic Ways / Hackways
A variable version of Ways to Win where each reel can display a different number of symbols on every spin (typically 2 to 7). The total ways to win changes every spin and can exceed 100,000+. Licensed from Big Time Gaming but widely adopted across providers.
Cluster Wins / Cluster / Grid Wins / Group Pays
Wins form when a group of identical symbols land touching each other horizontally or vertically, forming a cluster. No paylines or reels required — works on a grid. Minimum cluster size is usually 5+ symbols. Larger clusters pay more.
Scatter Win / Anywhere Pays / Count Pays
Symbols pay based on how many appear anywhere on the grid, regardless of position or adjacency. If enough matching symbols land on screen (typically 8+), you get paid. No lines, no clusters — just a symbol count across the entire grid.
Not Scatter Trigger — Scatter Pays is a win mechanic where scatter symbols pay based on count anywhere on the grid. Scatter Trigger is a bonus activation mechanic that opens a feature like free spins. One symbol can serve both roles.
Touching Pays / Neighbour Pays / Connected Pays
Symbols must be directly next to each other (horizontally or vertically) to form a win. Similar to cluster pays but with looser structural requirements — the shape of the group matters less than the adjacency chain.
Any Position Pays / Anywhere Wins / All Position Pays
Matching symbols anywhere on the reels count toward a win with no adjacency, sequence, or line requirement. Land enough of the same symbol in any positions, and you're paid. The loosest possible win evaluation.
Both Ways / Bidirectional Pays / Left and Right / Pay Both Ways / Win Either Way
Modifies any line-based or ways system to evaluate wins from right to left as well as the standard left to right. Effectively doubles the number of winning opportunities on every spin without changing the grid or bet.
Split Grid Ways / Dual Ways / Divided Ways
The reel grid is divided into separate sections, each generating their own independent ways to win. Those sections can then combine or interact under certain conditions, creating enormous win potential when both halves align.
Not Dual Grid — Split Ways divides one grid into sections generating independent ways that can combine. Dual Grid is two separate grids with their own mechanics.
Prize Drop / Instant Prize / Instant Payout / Random Prize / Cash Drop
A random cash award that triggers independently of any symbol combination, feature, or bonus. The game simply awards a prize — no clusters, no lines, no triggers required. Can happen on any spin.
14 mechanics
How the reels themselves behave — their structure, movement, reactions to wins, and transformations.
Tumbles / Cascades / Avalanche / Tumbling Reels / Collapsing Reels / Gravity Reels / Rolling Reels / Falling Symbols / Symbol Drop
When a win forms, the winning symbols are removed from the grid and new symbols fall/drop into the empty spaces from above. If the new arrangement creates another win, it cascades again. The chain continues until no new wins form — all on a single bet.
Growing Reels / Reel Expansion / Grid Expansion Static / Extra Rows
Additional rows are added to the grid during specific conditions — usually when entering a bonus round. A game that normally plays on 5×3 might expand to 5×6 for the duration of a feature, increasing ways to win and changing the math model.
Not Dynamic Grid Expansion — Expanding Reels set a larger grid at the start of a feature and it stays fixed. Dynamic Grid Expansion grows the grid incrementally mid-feature as wins cascade.
Progressive Grid / Collapsing Mine / Growing Grid / Unlocking Rows / Row Unlock
The grid physically grows mid-feature as wins form, progressively unlocking new rows or columns with each cascade or win event. Unlike static Expanding Reels (which add rows at feature start), this is gradual — the grid grows bigger the longer your win chain continues.
Not Expanding Reels — Dynamic Grid Expansion grows the grid progressively during gameplay with each win/cascade. Expanding Reels set the grid size once at feature start.
Respins / Extra Spin / Bonus Spin / Respin Feature
One or more free extra spins awarded by the game after specific events — landing certain symbols, near-miss combinations, or improving win conditions. A small second chance mechanic triggered automatically, not purchased by the player.
Not Buy Respin — Re-Spins are free extra spins triggered by gameplay. Buy Respin is a paid respin of individual reels chosen by the player.
Hold and Spin / Hold & Spin / Lock and Respin / Sticky Respin / Cash Respin / Money Respin
Qualifying symbols (often coins or special icons) lock in place while all remaining positions respin. If new qualifying symbols land, they lock too and respins reset (usually to 3). Continues until no new symbols appear or all positions are filled. A self-contained bonus loop.
Not Locking Reels — Hold & Respin locks individual qualifying symbols in place while all other positions respin. Locking Reels freezes entire reels.
Nudge Reels / Reel Nudge / Symbol Nudge / Nudge Up / Nudge Down / xNudge
After a spin lands, one or more reels shift up or down by one or more positions to create or improve a win. Can be random, triggered by near-misses, or guaranteed for specific symbol types (e.g., stacked wilds that always nudge fully into view, gaining a +1 multiplier per nudge step).
Synced Reels / Twin Reels / Synchronized Reels / Cloned Reels / Paired Reels / Mirror Reels / Dual Reel Sync
Two or more reels spin with identical symbol strips, guaranteeing matching columns. Which reels are linked can be random each spin or fixed. Creates large multi-reel matches that would be statistically rare otherwise.
Not Locking Reels — Linked Reels sync two or more reels to show identical symbol strips. Locking Reels freeze a reel result across multiple spins.
Infinite Reels / Endless Reels / Adding Reels
The grid starts at a fixed width and adds a new reel to the right each time a winning symbol appears on the rightmost reel. Theoretically, reels can keep adding indefinitely as long as wins keep extending. The grid grows horizontally with each successive win.
Giant Reels / Dual Reel Set / Main and Colossal
A second, larger reel set plays alongside the main grid. The colossal set typically mirrors some symbols from the main set or shares wilds between the two. Wins are evaluated on both grids, and interactions between them create unique bonus potential.
Not Colossal Symbols — Colossal Reels is a second, larger reel set alongside the main grid that mirrors or interacts with it. Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on a single grid.
Split Screen / Twin Grid / Double Grid Play / Parallel Grids / Multi Grid
Two separate grids play simultaneously, each with their own independent mechanics. The grids can interact by sharing wilds, combining multipliers, transferring symbols, or merging results. Distinct from Colossal Reels — both grids operate independently rather than one mirroring the other.
Not Colossal Reels or Split Ways — Dual Grid runs two fully independent grids that cross-pollinate (sharing wilds, combining multipliers). Colossal Reels mirrors one grid onto a larger one. Split Ways divides a single grid into sections for separate ways calculations.
Swap Reels / Reel Exchange / Reel Shuffle
Entire reel strips get exchanged between positions after the spin lands. Reel 1 might swap with Reel 5, or multiple reels shuffle simultaneously. Rearranges the grid layout to create new winning combinations from the same set of landed symbols.
Locked Reels / Reel Lock / Frozen Reels / Held Reels / Sticky Reels
Entire reels freeze in place for one or more subsequent spins while the remaining reels continue to spin normally. Distinct from Hold & Respin (locks individual symbols) and Linked Reels (syncs strips). The locked reel keeps its exact result across multiple spins.
Not Linked Reels or Hold & Respin — Locking Reels freeze entire reels for subsequent spins. Linked Reels force reels to show identical strips. Hold & Respin locks individual symbols (not entire reels).
Modifier Reel / Auxiliary Reel / Extra Reel / Bonus Reel / Hot Sauce Reel / Conveyor Reel
A separate reel strip outside the main grid that spins independently to deliver modifiers — extra wilds, multipliers, bombs, split symbols, or other effects. Does not participate in win formation directly. Acts as a randomized modifier delivery system for the main grid.
Not Colossal Reels — Side Reel is an auxiliary strip that delivers modifiers to the main grid (it does not generate wins itself). Colossal Reels is a second full reel set that generates its own wins.
Reel Respin / Paid Respin / Respin Purchase / Individual Reel Respin
The player pays a cost to respin one or more specific reels while keeping the rest of the grid locked. The cost is usually calculated based on the potential improvement. Distinct from Re-Spins (free, auto-triggered) and Feature Buy (purchases the full bonus).
Not Re-Spins — Buy Respin is a player-paid respin of specific individual reels. Re-Spins are free extra spins awarded by the game.
14 mechanics
Wild symbol variants and behaviors. Wilds substitute for other symbols to complete wins, but modern games have created an entire family of specialized wild types.
Wild Symbol / Standard Wild / Basic Wild / Substitute
The basic wild symbol substitutes for any regular paying symbol to help complete winning combinations. Typically does not substitute for scatters, bonus symbols, or other special symbols. The foundation that all other wild variants build upon.
Growing Wilds / Full Reel Wild / Stretching Wild
When this wild lands, it stretches to cover the entire reel (vertically) or the entire row (horizontally). One wild symbol becomes a full column or row of wilds, dramatically increasing substitution coverage across multiple paylines or ways.
Stacked Wild Symbols / Wild Stacks / Full Stack Wild
Multiple wild symbols appear stacked on top of each other on a single reel as part of the reel strip. When a full stack lands in view, it covers the entire reel. Unlike Expanding Wilds (one symbol stretches), stacked wilds are multiple individual wilds occupying consecutive positions.
Not Stacked Symbols — Stacked Wilds are wild substitutes arranged in a stack. Stacked Symbols are regular paying symbols in stacks; they do not substitute.
Locked Wilds / Persistent Wilds / Frozen Wilds / Held Wilds
Wild symbols that remain locked in their grid position for one or more subsequent spins. Especially impactful during free spins where they accumulate over time, gradually filling the grid with wilds as the feature progresses.
Shifting Wilds / Moving Wilds Directional / Wandering Wilds
Wild symbols move one position in a fixed direction (typically left) with each spin, remaining on the grid until they walk off the edge. Each step is essentially a free respin with the wild in a new position. Moves in a predictable, consistent direction.
Not Roaming, Jumping, or Trailing Wilds — Walking Wilds move one step in a fixed direction (usually left) per spin. Roaming Wilds move unpredictably to adjacent positions. Jumping Wilds teleport anywhere. Trailing Wilds leave copies behind.
Wild Trail / Shadow Wilds / Echo Wilds / Copy Wilds
A wild that leaves behind a copy of itself in its previous position as it moves across the grid. Combines the movement of Walking Wilds with duplication — the trail grows longer as the wild walks, creating multiple wilds from a single source.
Not Walking Wilds — Trailing Wilds move AND leave a wild copy behind in their previous position. Walking Wilds vacate their old position when they move.
Moving Wilds / Drifting Wilds / Floating Wilds
Wild symbols that move in unpredictable directions between spins — up, down, left, right, or diagonally. Unlike Walking Wilds (fixed direction), roaming wilds can go anywhere adjacent. Adds randomness to where wild coverage will appear next.
Not Walking or Jumping Wilds — Roaming Wilds move to adjacent positions in unpredictable directions. Walking Wilds follow a fixed direction. Jumping Wilds teleport to any random position.
Teleporting Wilds / Bouncing Wilds / Leaping Wilds / Random Position Wilds
Wild symbols that teleport to a completely random grid position on each spin, carrying a persistent multiplier that can grow over the course of a feature. Distinct from Walking/Roaming (which move to adjacent positions) — jumping wilds can land anywhere on the grid regardless of previous position.
Not Walking or Roaming Wilds — Jumping Wilds teleport to any random grid position each spin. Walking Wilds step one position in a fixed direction. Roaming Wilds drift to adjacent positions.
Added Wilds / Dropped Wilds / Wild Placement
The game places wild symbols onto random grid positions after the spin has landed. The wilds were not part of the original spin result — they are injected by the game engine. Might add 2, 3, 5 or more wilds to turn a losing spin into a winner.
Not Infectious Wilds — Random Wilds place wilds at random positions regardless of grid content. Infectious Wilds select a symbol type and convert all instances of it into wilds (spread is content-dependent).
Spreading Wilds / Virus Wilds / Contagious Wilds / Wild Infection
A wild that selects a random regular symbol type and converts every instance of that symbol on the grid into a wild. The infection spreads based on what's already on the reels. Multiple infectious wilds can each target different symbols, potentially turning large portions of the grid wild.
Not Random Wilds — Infectious Wilds choose a symbol type on the grid and convert every instance into wilds. Random Wilds place wilds at random positions without regard to existing symbols.
Exploding Wilds / xBomb / Destruction Wilds / Blast Wilds / Detonating Wilds / Wild Blast
A wild symbol that detonates when it participates in a win (or on landing), removing all adjacent symbols from the grid. Often carries or adds a persistent multiplier that increases with each explosion. The cleared positions allow new symbols to cascade in. Combines wild substitution with symbol destruction and multiplier accumulation.
Not Remove Symbols — Bomb Wilds are wild symbols that explode, removing adjacent symbols with an active event and often a growing multiplier. Remove Symbols is a passive feature that strips specific symbol types without explosion or multiplier.
Multiplying Wilds / Wild Multiplier / x2 Wild / x3 Wild
Wild symbols that substitute like a normal wild AND multiply the value of any win they participate in — by 2×, 3×, 5× or more. When multiple multiplier wilds contribute to the same win, their multipliers typically multiply together (e.g., 2× and 3× = 6×).
Not Multiplier Symbols — Multiplier Wilds substitute for other symbols AND carry a multiplier. Multiplier Symbols are their own symbol type with a multiplier but do not substitute.
Full Wild Reel / Entire Reel Wild / Wild Column
An entire reel turns completely wild, either randomly or as part of a feature trigger. Every position on that reel becomes a wild symbol, guaranteeing substitution on every payline or way passing through it. Can affect one or multiple reels.
Wild Overlay / Superimposed Wilds / Layered Wilds
Wild symbols placed on top of existing symbols without replacing the underlying reel result. The wild acts as a transparent layer — if the wild is removed or expires, the original symbol underneath is still there. Used in mechanics where wilds are temporary additions rather than replacements.
6 mechanics
Mechanics that scale win values by a factor. Can apply to individual wins, entire spins, specific grid positions, or accumulate over time.
Multiplier / Payout Multiplier / Win Boost
A specific multiplier applied to an individual win after it has been calculated. A 50-coin win with a 3× win multiplier pays 150 coins. Applied per winning combination, not globally.
Total Multiplier / Round Multiplier / Feature Multiplier / Base Multiplier
A multiplier that applies to all wins on all spins while it is active. Commonly used during free spins rounds and often increases as the round progresses. Everything pays more while this is in effect.
Column Multiplier / Reel Boost
A multiplier attached to a specific reel (column). Any win that includes a symbol from that reel gets boosted by the multiplier value displayed on it. Different reels can carry different multiplier values.
Not Position Multiplier — Reel Multiplier applies to an entire column. Position Multiplier applies to a specific individual cell. Reel multiplier boosts everything on that reel; position multiplier boosts only the specific grid square.
Cell Multiplier / Grid Multiplier / Spot Multiplier / Tile Multiplier / Square Multiplier
Multipliers tied to specific grid cells rather than reels or wins. Individual squares on the grid display a multiplier value, and any winning symbol occupying that cell gets its contribution boosted. Multipliers on cells typically accumulate across cascades — each new win on that cell increases its multiplier. Central to tumble games like Sugar Rush and Sweet Bonanza 1000.
Not Reel Multiplier — Position Multiplier is tied to a specific grid cell that can accumulate its own value. Reel Multiplier applies to an entire column uniformly.
Ramping Multiplier / Increasing Multiplier / Escalating Multiplier / Cascade Multiplier / Tumble Multiplier
A multiplier that increases over time or with each consecutive win event. In cascading reels games, it typically starts at 1× and goes up by 1 with each cascade: 1×, 2×, 3×, 4×, etc. Resets when the cascade chain ends or the feature concludes. Rewards long win chains.
Not Progressive Jackpot — Progressive Multiplier increases during a feature (e.g., +1× per cascade) and resets after. Progressive Jackpot is a prize pool that grows with bets over time. Unrelated mechanics.
Bet Multiplier / Enhanced Bet / Boosted Bet / Super Bet / xBet
An optional surcharge on top of the base bet (typically 10–100% extra) that unlocks a specific in-game advantage — better odds, enhanced features, or additional mechanics. The player pays more per spin voluntarily in exchange for improved conditions.
13 mechanics
Discrete events and game modes that break up the base game — bonus rounds, free spins, interactive features, and triggered events.
FS / Free Games / Bonus Spins / Feature Spins / Bonus Round
A set number of spins awarded at no cost, usually triggered by landing scatter symbols. Free spins rounds often come with enhanced mechanics — higher multipliers, more wilds, expanded reels, or special rules that don't apply in the base game. The primary source of big wins in most slots.
Retrigger / Extra Spins / Bonus Retrigger / Add Spins
The ability to earn additional free spins while already inside a free spins round. Land the trigger symbols again during the bonus and more spins get added to your total. Some games allow multiple retriggers, extending the round far beyond its initial length.
Buy Feature / Bonus Buy / Buy Bonus / Direct Buy / Feature Purchase
Pay a lump sum (typically 50× to 100× the base bet) to skip the base game entirely and jump straight into the bonus feature. Controversial, banned in some jurisdictions (UK, Belgium), and beloved by impatient players. The standard single-tier buy option.
Not Tiered Feature Buy or Lucky Buy — Feature Buy is a single fixed-price purchase to enter the bonus. Tiered Feature Buy offers multiple price points for different bonus levels. Lucky Buy randomizes the bonus level at a discount.
Pick & Click / Pick Me / Choose Feature / Selection Bonus / Pick and Win
Presents the player with a set of hidden items — chests, doors, envelopes — and asks them to choose. Each pick reveals a prize: coins, multipliers, extra spins, or upgrades. Outcomes are predetermined by the RNG, but the interaction creates a sense of agency.
Spin the Wheel / Bonus Wheel / Prize Wheel / Fortune Wheel / Wheel of Fortune
A large spinning wheel appears on screen with different prizes in each segment. The player spins the wheel and collects whatever it lands on — coins, multipliers, jackpot tiers, or feature upgrades. Visually dramatic and common on land-based cabinets.
Mystery Bonus / Random Bonus / Surprise Feature / Random Modifier
A feature that can trigger at any time during the base game without warning or specific symbol requirements. Might add wilds, transform symbols, award instant wins, or activate a full bonus round. The unpredictability and surprise element is the core appeal.
Not Mystery Symbols — Mystery Feature is a random bonus event that can do anything (add wilds, trigger free spins, award prizes). Mystery Symbols are a specific symbol type where all instances reveal the same randomly chosen symbol.
Random Trigger / Random Activation / Random Event
Any bonus or enhancement that activates randomly rather than through a specific symbol combination. Distinct from Mystery Feature (which is a single surprise event) — this is the broader category of any randomly-triggered mechanic.
Upgrade Feature / Feature Upgrade / Level Select / Bonus Choice / Pre-Bonus Selection
The ability to improve or choose your bonus configuration before or during the round. Some games offer a choice between different bonus tiers, or let you upgrade through gameplay — accepting fewer spins with more powerful mechanics.
Not Buy Enhancement — Bonus Upgrade is earned or chosen during gameplay to improve a bonus. Buy Enhancement is a paid purchase made before the bonus starts.
Double or Nothing / Risk Feature / Card Gamble / Coin Flip / 50/50 Gamble
Appears after a win and lets the player risk their winnings on a double-or-nothing bet — typically a coin flip or card-color guess. Win and the payout doubles, lose and it's gone. Some games allow multiple rounds.
Not Max Win Gamble — Gamble Feature is offered after any win for a 50/50 double-or-nothing. Max Win Gamble only triggers when near the game maximum win cap.
xBizarre / Endgame Gamble / Cap Gamble / Max Win Chance
A special gamble offered specifically when the player is near the game's maximum win cap after a bonus round. Each gamble gives a 50/50 chance to add another chunk toward the max win. Distinct from regular Gamble Feature — only available at extreme win levels and interacts with the max win ceiling.
Not Gamble Feature — Max Win Gamble is a special opportunity near the max win cap. Standard Gamble Feature is offered after any win.
Scatter Bonus Trigger / Scatter Activation / Bonus Scatter / Trigger Scatter
Scatter symbols that specifically serve as bonus activation triggers — landing 3+ scatters opens a feature like free spins. Distinct from Scatter Pays (where scatters pay based on count). The same scatter can do both in one game.
Not Scatter Pays — Scatter Trigger opens a bonus feature when enough scatters land. Scatter Pays awards a payout based on scatter count. The same symbol can do both in a single game.
Board Game Bonus / Path Bonus / Map Bonus / Journey Bonus / Trail Feature / Board Walk
A board-game-style bonus where the player advances along a trail or path, landing on spaces that award prizes, multipliers, extra moves, or feature triggers. Classic land-based cabinet mechanic experiencing a revival.
Continue Feature / Buy Extra Spin / Extend Bonus / Add Spin / Spin Extension
After a bonus round ends, the game offers to sell additional spins at a price calculated from the current bonus state (active multipliers, sticky wilds, grid conditions). Extends a completed bonus while preserving its accumulated state. Not a Feature Buy (pre-bonus) or Buy Respin (individual reel).
Not Feature Buy or Buy Respin — Extra Spin Purchase extends an active bonus round that has already been playing, priced on the current bonus state. Feature Buy skips the base game to enter a bonus. Buy Respin targets individual reels.
4 mechanics
Purchasable mechanics that let players pay to alter game conditions, trigger features, or enhance upcoming bonuses.
Multi-Level Buy / Tiered Bonus Buy / Multiple Buy Options / Bonus Tiers Buy
Multiple buy-in price points for different bonus levels. For example: 60× for basic free spins, 100× for enhanced, 500× for super. Each tier costs more but provides a more powerful bonus with better mechanics or more starting wilds.
Not Feature Buy — Tiered Feature Buy offers multiple price tiers (cheap to expensive) with different bonus levels. Standard Feature Buy has one fixed price and one bonus level.
Random Buy / Mystery Buy / Lucky Draw / Discount Buy / Gamble Buy
A discounted feature buy where the player pays a reduced price but receives a random bonus tier. Might get the basic bonus or the premium one — it's a gamble. Cheaper than buying the top tier directly, but you can't choose what you get.
Not Feature Buy — Lucky Buy is a discounted purchase where the bonus level is randomized. Standard Feature Buy has a fixed price and guaranteed bonus level.
Extra Scatter / Scatter Buy / Scatter Guarantee / Nolimit Booster / Add Scatter
Pay to add one or more extra scatter symbols to the next spin, improving trigger odds without guaranteeing it. You still need the remaining scatters to land naturally. Different from Ante Bet (which modifies odds passively every spin).
Not Ante Bet, Double Chance, or Bonus Chance — Buy Scatter adds extra scatters to one specific spin only. Ante Bet is a persistent per-spin surcharge. Double Chance doubles scatter rates persistently. Bonus Chance adjusts trigger conditions.
Buy Upgrade / Enhanced Buy / Pre-Loaded Buy / Boosted Start
Pay a premium to start a bonus round with pre-loaded upgrades — a starting multiplier of 3× instead of 1×, sticky wilds already placed, or enhanced grid conditions. The bonus triggers normally or via standard buy, but you're paying for a head start.
Not Bonus Upgrade — Buy Enhancement is a paid pre-purchase that boosts starting conditions of a bonus. Bonus Upgrade happens during or at the start of a bonus through gameplay or a choice mechanic (earned, not bought).
4 mechanics
Mechanics that create forward momentum — accumulation, leveling, and persistent advancement across spins or sessions.
Meter / Fill Meter / Progress Bar / Charge Meter / Feature Meter / Energy Bar
A visual meter that fills gradually as specific symbols land or events occur. When full, it triggers a bonus, modifier, or reward. Gives every spin a sense of progress. Resets after triggering.
Levels / Level Up / Multi-Level Bonus / Staged Bonus / Bonus Levels / Feature Progression
A bonus with multiple escalating levels, each more rewarding than the last. Advancement depends on performance, trigger symbols, or accumulated progress. Higher tiers unlock better multipliers, more powerful mechanics, or reduced symbol sets.
Symbol Collection / Collector / Gather Feature / Accumulate Symbols
Special symbols that land on the reels and activate values, wilds, or enhancements that have been building in specific grid positions. They act as activators — they don't do much alone, but they unlock value accumulated elsewhere.
Not Value Collect — Collect Symbols gather enhancements (wilds, upgrades, abstract bonuses) from grid positions. Value Collect specifically aggregates monetary values from coin/cash symbols into a single payout.
Persistent Collection / Cross-Session Progress / Permanent Upgrades / Lifetime Collection / Save Progress
Progress that carries over between bonus rounds or play sessions. Collections that take dozens of spins to complete, permanent upgrades that unlock over time, or cumulative achievements. Creates long-term player investment in a specific game.
8 mechanics
Mechanics built around symbols that carry specific monetary values rather than paying through traditional combinations.
Coins / Money Symbols / Gold Symbols / Token Symbols
Symbols displaying a specific value (coins, tokens). Their payout typically only activates during Hold & Respin features or bonus rounds — in the base game they may land but don't pay until collected by a feature.
Not Prize Symbols — Coin Symbols typically only pay during Hold & Respin or collection features. Prize Symbols pay on landing during normal base game spins. Value Symbols is the umbrella term for all.
Cash / Money Bags / Dollar Symbols / Bet Multiplier Symbols
Symbols displaying their value as a direct cash amount or bet multiplier. Functionally similar to Coin Symbols — the distinction is mostly thematic. Some games activate them only in features; others pay on landing.
Not Prize Symbols — Cash Symbols function like Coin Symbols but with different thematic presentation and value ranges. They typically pay during features, not in the base game.
Symbol Values / Numbered Symbols / Valued Symbols
The umbrella term for any symbol carrying a displayed numerical value — coins, gems, tokens, orbs. Used as a generic label covering all value-carrying symbol types regardless of visual presentation.
Umbrella term covering Coin Symbols, Cash Symbols, and Prize Symbols. Use this when the specific variant does not matter or is unclear.
Instant Pay Symbols / Direct Pay / Base Game Pay Symbols / Instant Value
Symbols that award their displayed cash value immediately on landing during the base game, without needing a feature. Distinct from Coin/Cash Symbols which typically only pay within bonus contexts. These pay on sight.
Not Coin Symbols or Cash Symbols — Prize Symbols pay their displayed value immediately on landing in the base game. Coin/Cash Symbols only pay during Hold & Respin or similar features.
Sack / Bag Symbol / Collector Coin / Value Sweep / Cash Collector / Payer Symbol
Symbols that sweep up all coin/cash values currently visible on the grid into a single combined payout. When a collector lands, it sums every value symbol on screen and pays the total. Central to Hold & Respin and coin features. Distinct from Collect (Symbols) which activates enhancements — this aggregates monetary values.
Not Collect (Symbols) — Value Collect sweeps up monetary values from coin/cash symbols into a payout. Collect Symbols gather non-monetary enhancements like wilds and upgrades.
Boost Values / Value Multiplier / Coin Boost
A feature that increases the values on all coin/value symbols currently on the grid. Might double every value, add a flat amount, or multiply by a random factor. Applied to existing symbols, not new ones.
Rising Values / Incrementing Values / Value Growth / Tick Up
Values on coin/value symbols increase incrementally with each game event — each spin, cascade, or respin. Values tick up gradually rather than receiving a one-time boost. Rewards patience and long feature runs.
Combine Values / Merge Coins / Value Combine / Symbol Merge / Coin Merge
Multiple value symbols physically combine into a single, larger symbol carrying the total of merged values. Two coins worth 2× and 3× become one worth 5×. Often paired with Hold & Respin where symbols can move and merge on the grid.
6 mechanics
The biggest possible payouts — fixed prizes, growing pools, and multi-tier jackpot systems.
Static Jackpot / Set Jackpot / Flat Jackpot / Non-Progressive Jackpot
Pays a predetermined, unchanging amount. The value is set by the game and stays constant regardless of play volume or time since the last hit.
Growing Jackpot / Pooled Jackpot / Accumulating Jackpot
Grows over time as a percentage of every bet feeds into the pool. Keeps climbing until won, then resets to a seed amount. Can be local (one game) or networked (many games/casinos). Can reach life-changing sums.
Not Progressive (Ramping) Multiplier — Progressive Jackpot is a prize pool that grows with every bet placed. Progressive Multiplier is a multiplier that ramps up during a feature (e.g., +1× per cascade). Unrelated mechanics sharing the word "progressive".
MHB Jackpot / Must Drop Jackpot / Guaranteed Jackpot / Drop By Jackpot / Must Go Jackpot
A progressive jackpot with a visible ceiling. Guaranteed to be won before reaching a specific amount. As the value approaches the ceiling, trigger probability increases. Creates a dynamic where players seek machines near the must-hit-by value.
Mini/Minor/Major/Grand / Jackpot Levels / Multi-Tier Jackpot / Bronze/Silver/Gold/Platinum / Tiered Jackpot
Multiple jackpot levels organized by size — commonly Mini, Minor, Major, Grand. Each tier has different value and odds. The smallest triggers frequently; the largest is rare but substantial.
Jackpot Spinner / Jackpot Prize Wheel / Tier Wheel
A dedicated wheel-spin event that determines which jackpot tier the player wins. The segment it lands on determines the prize — from smallest tier to grand jackpot.
Linked Jackpot / Wide Area Progressive / WAP / Network Jackpot / Cross-Game Jackpot / Shared Jackpot
A shared jackpot pool spanning multiple different game titles and potentially multiple casinos. Bets from all linked games feed the same pool, creating much larger jackpots than any single game could generate alone.
4 mechanics
Optional mechanics activated by the player that change the risk profile in exchange for better potential rewards.
Enhanced Bet / Boosted Spin / Super Stake / Feature Bet
An ongoing surcharge (typically 20–25% extra) in exchange for persistently improved odds of triggering the bonus. Active on every spin until the player turns it off.
Not Buy Scatter — Ante Bet is a persistent per-spin surcharge (20-25% extra) for better bonus odds. Buy Scatter is a one-time payment to add scatters to a single spin.
Extra Chance / 2x Chance / Scatter Boost
Specifically doubles the probability of one particular event — usually scatter appearance or bonus triggers. A targeted probability modifier.
Not Ante Bet — Double Chance specifically doubles scatter/trigger symbol probability. Ante Bet is a general surcharge for improved bonus odds.
Bonus Boost / Trigger Boost / Feature Chance
Increases the likelihood of entering the bonus round through a general mechanism — enhancing scatter symbols, changing trigger conditions, or lowering thresholds.
Not Ante Bet or Double Chance — Bonus Chance modifies trigger conditions or math model, which may differ from simply doubling scatter rates or adding a bet surcharge.
Bonus Guarantee / Forced Trigger / Auto Trigger / Guaranteed Feature
After paying a premium, the bonus is guaranteed to trigger within a set number of spins. If it doesn't trigger naturally, the game forces it. Bridges standard play and Feature Buy.
12 mechanics
Mechanics that change the symbols on the reels after landing — transforming, upgrading, splitting, adding, removing, or restructuring them.
Low to High / Symbol Promotion / Pay Upgrade / Symbol Ascend
Low-value symbols convert into higher-value ones. Common implementation: all instances of the lowest-paying symbol become the next tier up, compressing the paytable. Can chain through multiple tiers.
Transforming Symbols / Symbol Change / Symbol Morph / Symbol Convert
One symbol type changes into another. Turning a random regular symbol into a wild, or converting all of one type into a different matching type. Targeted — you know what becomes what.
Not Symbol Infection — Symbol Transform is a targeted change of one symbol type into another. Symbol Infection spreads from a source to adjacent positions in a chain reaction.
Spreading Symbols / Infectious Symbols / Symbol Spread / Contagious Symbols / Symbol Propagation / Infectious xWays
Non-wild symbols spread to adjacent positions, converting neighbours into copies of themselves. Propagates outward from the source. Distinct from Symbol Transform (random/targeted) — infection spreads organically from a point of origin.
Not Symbol Transform — Symbol Infection spreads organically from a source, converting adjacent or matching neighbours into copies. Symbol Transform is a targeted or random change of one type into another without spatial propagation.
Swap Symbols / Symbol Exchange / Symbol Switch
Two symbol types exchange — all hearts become stars and all stars become hearts. A lateral swap that can suddenly create winning combinations where none existed.
Split Symbols / xSplit / Splitting Symbols / Symbol Divide / Razor Split
A symbol or modifier splits all symbols in its row or reel into two, doubling their count and the ways to win through that position. The split symbol itself often becomes a wild. If split multiple times, symbols display a multiplier. Pioneered by Nolimit City's xSplit mechanic.
Symbol Inject / Symbol Drop / Extra Symbols / Bonus Symbols / Symbol Placement
Additional symbols placed onto the grid that weren't part of the original spin. The game drops extra wilds, scatters, or high-value symbols after the reels stop.
Symbol Removal / Symbol Clear / Symbol Destroy / Strip Symbols / Cosmic Sweep
Certain symbols are stripped off the grid entirely. Removes low-value or non-winning symbols to increase the concentration of winning symbols. Often paired with cascading reels where removed symbols create space for new ones.
Not Bomb Wilds — Remove Symbols passively strips specific symbol types from the grid. Bomb Wilds are wild symbols that actively explode adjacent symbols and typically carry a growing multiplier.
Mystery Stack / Secret Symbols / Unknown Symbols / ? Symbols / Reveal Symbols / xWays
Special placeholder symbols that all simultaneously reveal as the same randomly chosen regular symbol. Every mystery symbol on the grid reveals identically. Creates large groups of matching symbols from uncertain positions. The basis of Nolimit City's xWays mechanic.
Not Mystery Feature — Mystery Symbols are placeholder symbols that all reveal the same random symbol simultaneously. Mystery Feature is a random bonus event that could trigger any kind of enhancement.
Mega Symbols / Giant Symbols / Oversized Symbols / Big Symbols / 2x2 Symbols / 3x3 Symbols / Super Symbols
Oversized symbols occupying multiple grid positions (2×2, 3×3, or larger). Each cell they occupy counts as a separate instance, dramatically increasing win potential across multiple paylines or ways.
Not Colossal Reels — Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on one grid. Colossal Reels is a second full reel set that mirrors or interacts with the main grid.
Full Stacks / Symbol Stacks / Stacked Regulars / Full Reel Symbol
Non-wild regular symbols appearing in full stacks covering an entire reel. When a full stack lands in view, that reel shows only one symbol type, creating strong multi-payline wins. The non-wild counterpart to Stacked Wilds.
Not Stacked Wilds — Stacked Symbols are regular paying symbols in full stacks. Stacked Wilds are wild substitutes in stacks that can substitute for other symbols.
Multiplier Values / Symbol Multipliers / Multiplier Icons / Multiplier Positions
Non-wild symbols carrying a multiplier value. When they participate in a win or occupy specific positions, they multiply the payout. Often accumulate or double during tumble/cascade sequences. Distinct from Multiplier Wilds.
Not Multiplier Wilds — Multiplier Symbols are non-wild symbols that carry a multiplier value. Multiplier Wilds both substitute and multiply.
Locked Cells / Extra Cells / Bonus Cells / Hidden Positions / Enhancer Positions / Modifier Cells
Extra grid positions above, below, or beside the main reel area that start locked. They unlock when specific conditions are met (wilds landing, scatters appearing, bonus activation) and reveal special symbols — wilds, multipliers, mystery symbols, xWays, or split modifiers. They expand the effective grid when active and inject modifiers. Pioneered by Nolimit City, now widely adopted.
Not Expanding Reels — Enhancer Cells are hidden positions that unlock conditionally to reveal modifiers (wilds, multipliers, splits). Expanding Reels add standard rows with regular symbols at feature start.
10 mechanics
How the game determines what counts as a winning combination.
Lines / Winlines / Pay Lines / Fixed Lines / Active Lines
The game defines a fixed number of lines running across the reels. Matching symbols must land along one of these specific lines to form a win. The number of paylines is set by the game (10, 20, 50, etc.) and wins are evaluated left to right along each line.
All Ways / 243 Ways / 1024 Ways / Ways / All Ways Pay / Ways Pay
Matching symbols need to appear on consecutive reels starting from the left, in any row position. No fixed lines — if a matching symbol is anywhere on the next reel, it counts. Total ways = rows per reel multiplied together (e.g., 3×3×3×3×3 = 243 ways).
Big Time Gaming Megaways / BTG Megaways / Dynamic Ways / Hackways
A variable version of Ways to Win where each reel can display a different number of symbols on every spin (typically 2 to 7). The total ways to win changes every spin and can exceed 100,000+. Licensed from Big Time Gaming but widely adopted across providers.
Cluster Wins / Cluster / Grid Wins / Group Pays
Wins form when a group of identical symbols land touching each other horizontally or vertically, forming a cluster. No paylines or reels required — works on a grid. Minimum cluster size is usually 5+ symbols. Larger clusters pay more.
Scatter Win / Anywhere Pays / Count Pays
Symbols pay based on how many appear anywhere on the grid, regardless of position or adjacency. If enough matching symbols land on screen (typically 8+), you get paid. No lines, no clusters — just a symbol count across the entire grid.
Not Scatter Trigger — Scatter Pays is a win mechanic where scatter symbols pay based on count anywhere on the grid. Scatter Trigger is a bonus activation mechanic that opens a feature like free spins. One symbol can serve both roles.
Touching Pays / Neighbour Pays / Connected Pays
Symbols must be directly next to each other (horizontally or vertically) to form a win. Similar to cluster pays but with looser structural requirements — the shape of the group matters less than the adjacency chain.
Any Position Pays / Anywhere Wins / All Position Pays
Matching symbols anywhere on the reels count toward a win with no adjacency, sequence, or line requirement. Land enough of the same symbol in any positions, and you're paid. The loosest possible win evaluation.
Both Ways / Bidirectional Pays / Left and Right / Pay Both Ways / Win Either Way
Modifies any line-based or ways system to evaluate wins from right to left as well as the standard left to right. Effectively doubles the number of winning opportunities on every spin without changing the grid or bet.
Split Grid Ways / Dual Ways / Divided Ways
The reel grid is divided into separate sections, each generating their own independent ways to win. Those sections can then combine or interact under certain conditions, creating enormous win potential when both halves align.
Not Dual Grid — Split Ways divides one grid into sections generating independent ways that can combine. Dual Grid is two separate grids with their own mechanics.
Prize Drop / Instant Prize / Instant Payout / Random Prize / Cash Drop
A random cash award that triggers independently of any symbol combination, feature, or bonus. The game simply awards a prize — no clusters, no lines, no triggers required. Can happen on any spin.
14 mechanics
How the reels themselves behave — their structure, movement, reactions to wins, and transformations.
Tumbles / Cascades / Avalanche / Tumbling Reels / Collapsing Reels / Gravity Reels / Rolling Reels / Falling Symbols / Symbol Drop
When a win forms, the winning symbols are removed from the grid and new symbols fall/drop into the empty spaces from above. If the new arrangement creates another win, it cascades again. The chain continues until no new wins form — all on a single bet.
Growing Reels / Reel Expansion / Grid Expansion Static / Extra Rows
Additional rows are added to the grid during specific conditions — usually when entering a bonus round. A game that normally plays on 5×3 might expand to 5×6 for the duration of a feature, increasing ways to win and changing the math model.
Not Dynamic Grid Expansion — Expanding Reels set a larger grid at the start of a feature and it stays fixed. Dynamic Grid Expansion grows the grid incrementally mid-feature as wins cascade.
Progressive Grid / Collapsing Mine / Growing Grid / Unlocking Rows / Row Unlock
The grid physically grows mid-feature as wins form, progressively unlocking new rows or columns with each cascade or win event. Unlike static Expanding Reels (which add rows at feature start), this is gradual — the grid grows bigger the longer your win chain continues.
Not Expanding Reels — Dynamic Grid Expansion grows the grid progressively during gameplay with each win/cascade. Expanding Reels set the grid size once at feature start.
Respins / Extra Spin / Bonus Spin / Respin Feature
One or more free extra spins awarded by the game after specific events — landing certain symbols, near-miss combinations, or improving win conditions. A small second chance mechanic triggered automatically, not purchased by the player.
Not Buy Respin — Re-Spins are free extra spins triggered by gameplay. Buy Respin is a paid respin of individual reels chosen by the player.
Hold and Spin / Hold & Spin / Lock and Respin / Sticky Respin / Cash Respin / Money Respin
Qualifying symbols (often coins or special icons) lock in place while all remaining positions respin. If new qualifying symbols land, they lock too and respins reset (usually to 3). Continues until no new symbols appear or all positions are filled. A self-contained bonus loop.
Not Locking Reels — Hold & Respin locks individual qualifying symbols in place while all other positions respin. Locking Reels freezes entire reels.
Nudge Reels / Reel Nudge / Symbol Nudge / Nudge Up / Nudge Down / xNudge
After a spin lands, one or more reels shift up or down by one or more positions to create or improve a win. Can be random, triggered by near-misses, or guaranteed for specific symbol types (e.g., stacked wilds that always nudge fully into view, gaining a +1 multiplier per nudge step).
Synced Reels / Twin Reels / Synchronized Reels / Cloned Reels / Paired Reels / Mirror Reels / Dual Reel Sync
Two or more reels spin with identical symbol strips, guaranteeing matching columns. Which reels are linked can be random each spin or fixed. Creates large multi-reel matches that would be statistically rare otherwise.
Not Locking Reels — Linked Reels sync two or more reels to show identical symbol strips. Locking Reels freeze a reel result across multiple spins.
Infinite Reels / Endless Reels / Adding Reels
The grid starts at a fixed width and adds a new reel to the right each time a winning symbol appears on the rightmost reel. Theoretically, reels can keep adding indefinitely as long as wins keep extending. The grid grows horizontally with each successive win.
Giant Reels / Dual Reel Set / Main and Colossal
A second, larger reel set plays alongside the main grid. The colossal set typically mirrors some symbols from the main set or shares wilds between the two. Wins are evaluated on both grids, and interactions between them create unique bonus potential.
Not Colossal Symbols — Colossal Reels is a second, larger reel set alongside the main grid that mirrors or interacts with it. Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on a single grid.
Split Screen / Twin Grid / Double Grid Play / Parallel Grids / Multi Grid
Two separate grids play simultaneously, each with their own independent mechanics. The grids can interact by sharing wilds, combining multipliers, transferring symbols, or merging results. Distinct from Colossal Reels — both grids operate independently rather than one mirroring the other.
Not Colossal Reels or Split Ways — Dual Grid runs two fully independent grids that cross-pollinate (sharing wilds, combining multipliers). Colossal Reels mirrors one grid onto a larger one. Split Ways divides a single grid into sections for separate ways calculations.
Swap Reels / Reel Exchange / Reel Shuffle
Entire reel strips get exchanged between positions after the spin lands. Reel 1 might swap with Reel 5, or multiple reels shuffle simultaneously. Rearranges the grid layout to create new winning combinations from the same set of landed symbols.
Locked Reels / Reel Lock / Frozen Reels / Held Reels / Sticky Reels
Entire reels freeze in place for one or more subsequent spins while the remaining reels continue to spin normally. Distinct from Hold & Respin (locks individual symbols) and Linked Reels (syncs strips). The locked reel keeps its exact result across multiple spins.
Not Linked Reels or Hold & Respin — Locking Reels freeze entire reels for subsequent spins. Linked Reels force reels to show identical strips. Hold & Respin locks individual symbols (not entire reels).
Modifier Reel / Auxiliary Reel / Extra Reel / Bonus Reel / Hot Sauce Reel / Conveyor Reel
A separate reel strip outside the main grid that spins independently to deliver modifiers — extra wilds, multipliers, bombs, split symbols, or other effects. Does not participate in win formation directly. Acts as a randomized modifier delivery system for the main grid.
Not Colossal Reels — Side Reel is an auxiliary strip that delivers modifiers to the main grid (it does not generate wins itself). Colossal Reels is a second full reel set that generates its own wins.
Reel Respin / Paid Respin / Respin Purchase / Individual Reel Respin
The player pays a cost to respin one or more specific reels while keeping the rest of the grid locked. The cost is usually calculated based on the potential improvement. Distinct from Re-Spins (free, auto-triggered) and Feature Buy (purchases the full bonus).
Not Re-Spins — Buy Respin is a player-paid respin of specific individual reels. Re-Spins are free extra spins awarded by the game.
14 mechanics
Wild symbol variants and behaviors. Wilds substitute for other symbols to complete wins, but modern games have created an entire family of specialized wild types.
Wild Symbol / Standard Wild / Basic Wild / Substitute
The basic wild symbol substitutes for any regular paying symbol to help complete winning combinations. Typically does not substitute for scatters, bonus symbols, or other special symbols. The foundation that all other wild variants build upon.
Growing Wilds / Full Reel Wild / Stretching Wild
When this wild lands, it stretches to cover the entire reel (vertically) or the entire row (horizontally). One wild symbol becomes a full column or row of wilds, dramatically increasing substitution coverage across multiple paylines or ways.
Stacked Wild Symbols / Wild Stacks / Full Stack Wild
Multiple wild symbols appear stacked on top of each other on a single reel as part of the reel strip. When a full stack lands in view, it covers the entire reel. Unlike Expanding Wilds (one symbol stretches), stacked wilds are multiple individual wilds occupying consecutive positions.
Not Stacked Symbols — Stacked Wilds are wild substitutes arranged in a stack. Stacked Symbols are regular paying symbols in stacks; they do not substitute.
Locked Wilds / Persistent Wilds / Frozen Wilds / Held Wilds
Wild symbols that remain locked in their grid position for one or more subsequent spins. Especially impactful during free spins where they accumulate over time, gradually filling the grid with wilds as the feature progresses.
Shifting Wilds / Moving Wilds Directional / Wandering Wilds
Wild symbols move one position in a fixed direction (typically left) with each spin, remaining on the grid until they walk off the edge. Each step is essentially a free respin with the wild in a new position. Moves in a predictable, consistent direction.
Not Roaming, Jumping, or Trailing Wilds — Walking Wilds move one step in a fixed direction (usually left) per spin. Roaming Wilds move unpredictably to adjacent positions. Jumping Wilds teleport anywhere. Trailing Wilds leave copies behind.
Wild Trail / Shadow Wilds / Echo Wilds / Copy Wilds
A wild that leaves behind a copy of itself in its previous position as it moves across the grid. Combines the movement of Walking Wilds with duplication — the trail grows longer as the wild walks, creating multiple wilds from a single source.
Not Walking Wilds — Trailing Wilds move AND leave a wild copy behind in their previous position. Walking Wilds vacate their old position when they move.
Moving Wilds / Drifting Wilds / Floating Wilds
Wild symbols that move in unpredictable directions between spins — up, down, left, right, or diagonally. Unlike Walking Wilds (fixed direction), roaming wilds can go anywhere adjacent. Adds randomness to where wild coverage will appear next.
Not Walking or Jumping Wilds — Roaming Wilds move to adjacent positions in unpredictable directions. Walking Wilds follow a fixed direction. Jumping Wilds teleport to any random position.
Teleporting Wilds / Bouncing Wilds / Leaping Wilds / Random Position Wilds
Wild symbols that teleport to a completely random grid position on each spin, carrying a persistent multiplier that can grow over the course of a feature. Distinct from Walking/Roaming (which move to adjacent positions) — jumping wilds can land anywhere on the grid regardless of previous position.
Not Walking or Roaming Wilds — Jumping Wilds teleport to any random grid position each spin. Walking Wilds step one position in a fixed direction. Roaming Wilds drift to adjacent positions.
Added Wilds / Dropped Wilds / Wild Placement
The game places wild symbols onto random grid positions after the spin has landed. The wilds were not part of the original spin result — they are injected by the game engine. Might add 2, 3, 5 or more wilds to turn a losing spin into a winner.
Not Infectious Wilds — Random Wilds place wilds at random positions regardless of grid content. Infectious Wilds select a symbol type and convert all instances of it into wilds (spread is content-dependent).
Spreading Wilds / Virus Wilds / Contagious Wilds / Wild Infection
A wild that selects a random regular symbol type and converts every instance of that symbol on the grid into a wild. The infection spreads based on what's already on the reels. Multiple infectious wilds can each target different symbols, potentially turning large portions of the grid wild.
Not Random Wilds — Infectious Wilds choose a symbol type on the grid and convert every instance into wilds. Random Wilds place wilds at random positions without regard to existing symbols.
Exploding Wilds / xBomb / Destruction Wilds / Blast Wilds / Detonating Wilds / Wild Blast
A wild symbol that detonates when it participates in a win (or on landing), removing all adjacent symbols from the grid. Often carries or adds a persistent multiplier that increases with each explosion. The cleared positions allow new symbols to cascade in. Combines wild substitution with symbol destruction and multiplier accumulation.
Not Remove Symbols — Bomb Wilds are wild symbols that explode, removing adjacent symbols with an active event and often a growing multiplier. Remove Symbols is a passive feature that strips specific symbol types without explosion or multiplier.
Multiplying Wilds / Wild Multiplier / x2 Wild / x3 Wild
Wild symbols that substitute like a normal wild AND multiply the value of any win they participate in — by 2×, 3×, 5× or more. When multiple multiplier wilds contribute to the same win, their multipliers typically multiply together (e.g., 2× and 3× = 6×).
Not Multiplier Symbols — Multiplier Wilds substitute for other symbols AND carry a multiplier. Multiplier Symbols are their own symbol type with a multiplier but do not substitute.
Full Wild Reel / Entire Reel Wild / Wild Column
An entire reel turns completely wild, either randomly or as part of a feature trigger. Every position on that reel becomes a wild symbol, guaranteeing substitution on every payline or way passing through it. Can affect one or multiple reels.
Wild Overlay / Superimposed Wilds / Layered Wilds
Wild symbols placed on top of existing symbols without replacing the underlying reel result. The wild acts as a transparent layer — if the wild is removed or expires, the original symbol underneath is still there. Used in mechanics where wilds are temporary additions rather than replacements.
6 mechanics
Mechanics that scale win values by a factor. Can apply to individual wins, entire spins, specific grid positions, or accumulate over time.
Multiplier / Payout Multiplier / Win Boost
A specific multiplier applied to an individual win after it has been calculated. A 50-coin win with a 3× win multiplier pays 150 coins. Applied per winning combination, not globally.
Total Multiplier / Round Multiplier / Feature Multiplier / Base Multiplier
A multiplier that applies to all wins on all spins while it is active. Commonly used during free spins rounds and often increases as the round progresses. Everything pays more while this is in effect.
Column Multiplier / Reel Boost
A multiplier attached to a specific reel (column). Any win that includes a symbol from that reel gets boosted by the multiplier value displayed on it. Different reels can carry different multiplier values.
Not Position Multiplier — Reel Multiplier applies to an entire column. Position Multiplier applies to a specific individual cell. Reel multiplier boosts everything on that reel; position multiplier boosts only the specific grid square.
Cell Multiplier / Grid Multiplier / Spot Multiplier / Tile Multiplier / Square Multiplier
Multipliers tied to specific grid cells rather than reels or wins. Individual squares on the grid display a multiplier value, and any winning symbol occupying that cell gets its contribution boosted. Multipliers on cells typically accumulate across cascades — each new win on that cell increases its multiplier. Central to tumble games like Sugar Rush and Sweet Bonanza 1000.
Not Reel Multiplier — Position Multiplier is tied to a specific grid cell that can accumulate its own value. Reel Multiplier applies to an entire column uniformly.
Ramping Multiplier / Increasing Multiplier / Escalating Multiplier / Cascade Multiplier / Tumble Multiplier
A multiplier that increases over time or with each consecutive win event. In cascading reels games, it typically starts at 1× and goes up by 1 with each cascade: 1×, 2×, 3×, 4×, etc. Resets when the cascade chain ends or the feature concludes. Rewards long win chains.
Not Progressive Jackpot — Progressive Multiplier increases during a feature (e.g., +1× per cascade) and resets after. Progressive Jackpot is a prize pool that grows with bets over time. Unrelated mechanics.
Bet Multiplier / Enhanced Bet / Boosted Bet / Super Bet / xBet
An optional surcharge on top of the base bet (typically 10–100% extra) that unlocks a specific in-game advantage — better odds, enhanced features, or additional mechanics. The player pays more per spin voluntarily in exchange for improved conditions.
13 mechanics
Discrete events and game modes that break up the base game — bonus rounds, free spins, interactive features, and triggered events.
FS / Free Games / Bonus Spins / Feature Spins / Bonus Round
A set number of spins awarded at no cost, usually triggered by landing scatter symbols. Free spins rounds often come with enhanced mechanics — higher multipliers, more wilds, expanded reels, or special rules that don't apply in the base game. The primary source of big wins in most slots.
Retrigger / Extra Spins / Bonus Retrigger / Add Spins
The ability to earn additional free spins while already inside a free spins round. Land the trigger symbols again during the bonus and more spins get added to your total. Some games allow multiple retriggers, extending the round far beyond its initial length.
Buy Feature / Bonus Buy / Buy Bonus / Direct Buy / Feature Purchase
Pay a lump sum (typically 50× to 100× the base bet) to skip the base game entirely and jump straight into the bonus feature. Controversial, banned in some jurisdictions (UK, Belgium), and beloved by impatient players. The standard single-tier buy option.
Not Tiered Feature Buy or Lucky Buy — Feature Buy is a single fixed-price purchase to enter the bonus. Tiered Feature Buy offers multiple price points for different bonus levels. Lucky Buy randomizes the bonus level at a discount.
Pick & Click / Pick Me / Choose Feature / Selection Bonus / Pick and Win
Presents the player with a set of hidden items — chests, doors, envelopes — and asks them to choose. Each pick reveals a prize: coins, multipliers, extra spins, or upgrades. Outcomes are predetermined by the RNG, but the interaction creates a sense of agency.
Spin the Wheel / Bonus Wheel / Prize Wheel / Fortune Wheel / Wheel of Fortune
A large spinning wheel appears on screen with different prizes in each segment. The player spins the wheel and collects whatever it lands on — coins, multipliers, jackpot tiers, or feature upgrades. Visually dramatic and common on land-based cabinets.
Mystery Bonus / Random Bonus / Surprise Feature / Random Modifier
A feature that can trigger at any time during the base game without warning or specific symbol requirements. Might add wilds, transform symbols, award instant wins, or activate a full bonus round. The unpredictability and surprise element is the core appeal.
Not Mystery Symbols — Mystery Feature is a random bonus event that can do anything (add wilds, trigger free spins, award prizes). Mystery Symbols are a specific symbol type where all instances reveal the same randomly chosen symbol.
Random Trigger / Random Activation / Random Event
Any bonus or enhancement that activates randomly rather than through a specific symbol combination. Distinct from Mystery Feature (which is a single surprise event) — this is the broader category of any randomly-triggered mechanic.
Upgrade Feature / Feature Upgrade / Level Select / Bonus Choice / Pre-Bonus Selection
The ability to improve or choose your bonus configuration before or during the round. Some games offer a choice between different bonus tiers, or let you upgrade through gameplay — accepting fewer spins with more powerful mechanics.
Not Buy Enhancement — Bonus Upgrade is earned or chosen during gameplay to improve a bonus. Buy Enhancement is a paid purchase made before the bonus starts.
Double or Nothing / Risk Feature / Card Gamble / Coin Flip / 50/50 Gamble
Appears after a win and lets the player risk their winnings on a double-or-nothing bet — typically a coin flip or card-color guess. Win and the payout doubles, lose and it's gone. Some games allow multiple rounds.
Not Max Win Gamble — Gamble Feature is offered after any win for a 50/50 double-or-nothing. Max Win Gamble only triggers when near the game maximum win cap.
xBizarre / Endgame Gamble / Cap Gamble / Max Win Chance
A special gamble offered specifically when the player is near the game's maximum win cap after a bonus round. Each gamble gives a 50/50 chance to add another chunk toward the max win. Distinct from regular Gamble Feature — only available at extreme win levels and interacts with the max win ceiling.
Not Gamble Feature — Max Win Gamble is a special opportunity near the max win cap. Standard Gamble Feature is offered after any win.
Scatter Bonus Trigger / Scatter Activation / Bonus Scatter / Trigger Scatter
Scatter symbols that specifically serve as bonus activation triggers — landing 3+ scatters opens a feature like free spins. Distinct from Scatter Pays (where scatters pay based on count). The same scatter can do both in one game.
Not Scatter Pays — Scatter Trigger opens a bonus feature when enough scatters land. Scatter Pays awards a payout based on scatter count. The same symbol can do both in a single game.
Board Game Bonus / Path Bonus / Map Bonus / Journey Bonus / Trail Feature / Board Walk
A board-game-style bonus where the player advances along a trail or path, landing on spaces that award prizes, multipliers, extra moves, or feature triggers. Classic land-based cabinet mechanic experiencing a revival.
Continue Feature / Buy Extra Spin / Extend Bonus / Add Spin / Spin Extension
After a bonus round ends, the game offers to sell additional spins at a price calculated from the current bonus state (active multipliers, sticky wilds, grid conditions). Extends a completed bonus while preserving its accumulated state. Not a Feature Buy (pre-bonus) or Buy Respin (individual reel).
Not Feature Buy or Buy Respin — Extra Spin Purchase extends an active bonus round that has already been playing, priced on the current bonus state. Feature Buy skips the base game to enter a bonus. Buy Respin targets individual reels.
4 mechanics
Purchasable mechanics that let players pay to alter game conditions, trigger features, or enhance upcoming bonuses.
Multi-Level Buy / Tiered Bonus Buy / Multiple Buy Options / Bonus Tiers Buy
Multiple buy-in price points for different bonus levels. For example: 60× for basic free spins, 100× for enhanced, 500× for super. Each tier costs more but provides a more powerful bonus with better mechanics or more starting wilds.
Not Feature Buy — Tiered Feature Buy offers multiple price tiers (cheap to expensive) with different bonus levels. Standard Feature Buy has one fixed price and one bonus level.
Random Buy / Mystery Buy / Lucky Draw / Discount Buy / Gamble Buy
A discounted feature buy where the player pays a reduced price but receives a random bonus tier. Might get the basic bonus or the premium one — it's a gamble. Cheaper than buying the top tier directly, but you can't choose what you get.
Not Feature Buy — Lucky Buy is a discounted purchase where the bonus level is randomized. Standard Feature Buy has a fixed price and guaranteed bonus level.
Extra Scatter / Scatter Buy / Scatter Guarantee / Nolimit Booster / Add Scatter
Pay to add one or more extra scatter symbols to the next spin, improving trigger odds without guaranteeing it. You still need the remaining scatters to land naturally. Different from Ante Bet (which modifies odds passively every spin).
Not Ante Bet, Double Chance, or Bonus Chance — Buy Scatter adds extra scatters to one specific spin only. Ante Bet is a persistent per-spin surcharge. Double Chance doubles scatter rates persistently. Bonus Chance adjusts trigger conditions.
Buy Upgrade / Enhanced Buy / Pre-Loaded Buy / Boosted Start
Pay a premium to start a bonus round with pre-loaded upgrades — a starting multiplier of 3× instead of 1×, sticky wilds already placed, or enhanced grid conditions. The bonus triggers normally or via standard buy, but you're paying for a head start.
Not Bonus Upgrade — Buy Enhancement is a paid pre-purchase that boosts starting conditions of a bonus. Bonus Upgrade happens during or at the start of a bonus through gameplay or a choice mechanic (earned, not bought).
4 mechanics
Mechanics that create forward momentum — accumulation, leveling, and persistent advancement across spins or sessions.
Meter / Fill Meter / Progress Bar / Charge Meter / Feature Meter / Energy Bar
A visual meter that fills gradually as specific symbols land or events occur. When full, it triggers a bonus, modifier, or reward. Gives every spin a sense of progress. Resets after triggering.
Levels / Level Up / Multi-Level Bonus / Staged Bonus / Bonus Levels / Feature Progression
A bonus with multiple escalating levels, each more rewarding than the last. Advancement depends on performance, trigger symbols, or accumulated progress. Higher tiers unlock better multipliers, more powerful mechanics, or reduced symbol sets.
Symbol Collection / Collector / Gather Feature / Accumulate Symbols
Special symbols that land on the reels and activate values, wilds, or enhancements that have been building in specific grid positions. They act as activators — they don't do much alone, but they unlock value accumulated elsewhere.
Not Value Collect — Collect Symbols gather enhancements (wilds, upgrades, abstract bonuses) from grid positions. Value Collect specifically aggregates monetary values from coin/cash symbols into a single payout.
Persistent Collection / Cross-Session Progress / Permanent Upgrades / Lifetime Collection / Save Progress
Progress that carries over between bonus rounds or play sessions. Collections that take dozens of spins to complete, permanent upgrades that unlock over time, or cumulative achievements. Creates long-term player investment in a specific game.
8 mechanics
Mechanics built around symbols that carry specific monetary values rather than paying through traditional combinations.
Coins / Money Symbols / Gold Symbols / Token Symbols
Symbols displaying a specific value (coins, tokens). Their payout typically only activates during Hold & Respin features or bonus rounds — in the base game they may land but don't pay until collected by a feature.
Not Prize Symbols — Coin Symbols typically only pay during Hold & Respin or collection features. Prize Symbols pay on landing during normal base game spins. Value Symbols is the umbrella term for all.
Cash / Money Bags / Dollar Symbols / Bet Multiplier Symbols
Symbols displaying their value as a direct cash amount or bet multiplier. Functionally similar to Coin Symbols — the distinction is mostly thematic. Some games activate them only in features; others pay on landing.
Not Prize Symbols — Cash Symbols function like Coin Symbols but with different thematic presentation and value ranges. They typically pay during features, not in the base game.
Symbol Values / Numbered Symbols / Valued Symbols
The umbrella term for any symbol carrying a displayed numerical value — coins, gems, tokens, orbs. Used as a generic label covering all value-carrying symbol types regardless of visual presentation.
Umbrella term covering Coin Symbols, Cash Symbols, and Prize Symbols. Use this when the specific variant does not matter or is unclear.
Instant Pay Symbols / Direct Pay / Base Game Pay Symbols / Instant Value
Symbols that award their displayed cash value immediately on landing during the base game, without needing a feature. Distinct from Coin/Cash Symbols which typically only pay within bonus contexts. These pay on sight.
Not Coin Symbols or Cash Symbols — Prize Symbols pay their displayed value immediately on landing in the base game. Coin/Cash Symbols only pay during Hold & Respin or similar features.
Sack / Bag Symbol / Collector Coin / Value Sweep / Cash Collector / Payer Symbol
Symbols that sweep up all coin/cash values currently visible on the grid into a single combined payout. When a collector lands, it sums every value symbol on screen and pays the total. Central to Hold & Respin and coin features. Distinct from Collect (Symbols) which activates enhancements — this aggregates monetary values.
Not Collect (Symbols) — Value Collect sweeps up monetary values from coin/cash symbols into a payout. Collect Symbols gather non-monetary enhancements like wilds and upgrades.
Boost Values / Value Multiplier / Coin Boost
A feature that increases the values on all coin/value symbols currently on the grid. Might double every value, add a flat amount, or multiply by a random factor. Applied to existing symbols, not new ones.
Rising Values / Incrementing Values / Value Growth / Tick Up
Values on coin/value symbols increase incrementally with each game event — each spin, cascade, or respin. Values tick up gradually rather than receiving a one-time boost. Rewards patience and long feature runs.
Combine Values / Merge Coins / Value Combine / Symbol Merge / Coin Merge
Multiple value symbols physically combine into a single, larger symbol carrying the total of merged values. Two coins worth 2× and 3× become one worth 5×. Often paired with Hold & Respin where symbols can move and merge on the grid.
6 mechanics
The biggest possible payouts — fixed prizes, growing pools, and multi-tier jackpot systems.
Static Jackpot / Set Jackpot / Flat Jackpot / Non-Progressive Jackpot
Pays a predetermined, unchanging amount. The value is set by the game and stays constant regardless of play volume or time since the last hit.
Growing Jackpot / Pooled Jackpot / Accumulating Jackpot
Grows over time as a percentage of every bet feeds into the pool. Keeps climbing until won, then resets to a seed amount. Can be local (one game) or networked (many games/casinos). Can reach life-changing sums.
Not Progressive (Ramping) Multiplier — Progressive Jackpot is a prize pool that grows with every bet placed. Progressive Multiplier is a multiplier that ramps up during a feature (e.g., +1× per cascade). Unrelated mechanics sharing the word "progressive".
MHB Jackpot / Must Drop Jackpot / Guaranteed Jackpot / Drop By Jackpot / Must Go Jackpot
A progressive jackpot with a visible ceiling. Guaranteed to be won before reaching a specific amount. As the value approaches the ceiling, trigger probability increases. Creates a dynamic where players seek machines near the must-hit-by value.
Mini/Minor/Major/Grand / Jackpot Levels / Multi-Tier Jackpot / Bronze/Silver/Gold/Platinum / Tiered Jackpot
Multiple jackpot levels organized by size — commonly Mini, Minor, Major, Grand. Each tier has different value and odds. The smallest triggers frequently; the largest is rare but substantial.
Jackpot Spinner / Jackpot Prize Wheel / Tier Wheel
A dedicated wheel-spin event that determines which jackpot tier the player wins. The segment it lands on determines the prize — from smallest tier to grand jackpot.
Linked Jackpot / Wide Area Progressive / WAP / Network Jackpot / Cross-Game Jackpot / Shared Jackpot
A shared jackpot pool spanning multiple different game titles and potentially multiple casinos. Bets from all linked games feed the same pool, creating much larger jackpots than any single game could generate alone.
4 mechanics
Optional mechanics activated by the player that change the risk profile in exchange for better potential rewards.
Enhanced Bet / Boosted Spin / Super Stake / Feature Bet
An ongoing surcharge (typically 20–25% extra) in exchange for persistently improved odds of triggering the bonus. Active on every spin until the player turns it off.
Not Buy Scatter — Ante Bet is a persistent per-spin surcharge (20-25% extra) for better bonus odds. Buy Scatter is a one-time payment to add scatters to a single spin.
Extra Chance / 2x Chance / Scatter Boost
Specifically doubles the probability of one particular event — usually scatter appearance or bonus triggers. A targeted probability modifier.
Not Ante Bet — Double Chance specifically doubles scatter/trigger symbol probability. Ante Bet is a general surcharge for improved bonus odds.
Bonus Boost / Trigger Boost / Feature Chance
Increases the likelihood of entering the bonus round through a general mechanism — enhancing scatter symbols, changing trigger conditions, or lowering thresholds.
Not Ante Bet or Double Chance — Bonus Chance modifies trigger conditions or math model, which may differ from simply doubling scatter rates or adding a bet surcharge.
Bonus Guarantee / Forced Trigger / Auto Trigger / Guaranteed Feature
After paying a premium, the bonus is guaranteed to trigger within a set number of spins. If it doesn't trigger naturally, the game forces it. Bridges standard play and Feature Buy.
12 mechanics
Mechanics that change the symbols on the reels after landing — transforming, upgrading, splitting, adding, removing, or restructuring them.
Low to High / Symbol Promotion / Pay Upgrade / Symbol Ascend
Low-value symbols convert into higher-value ones. Common implementation: all instances of the lowest-paying symbol become the next tier up, compressing the paytable. Can chain through multiple tiers.
Transforming Symbols / Symbol Change / Symbol Morph / Symbol Convert
One symbol type changes into another. Turning a random regular symbol into a wild, or converting all of one type into a different matching type. Targeted — you know what becomes what.
Not Symbol Infection — Symbol Transform is a targeted change of one symbol type into another. Symbol Infection spreads from a source to adjacent positions in a chain reaction.
Spreading Symbols / Infectious Symbols / Symbol Spread / Contagious Symbols / Symbol Propagation / Infectious xWays
Non-wild symbols spread to adjacent positions, converting neighbours into copies of themselves. Propagates outward from the source. Distinct from Symbol Transform (random/targeted) — infection spreads organically from a point of origin.
Not Symbol Transform — Symbol Infection spreads organically from a source, converting adjacent or matching neighbours into copies. Symbol Transform is a targeted or random change of one type into another without spatial propagation.
Swap Symbols / Symbol Exchange / Symbol Switch
Two symbol types exchange — all hearts become stars and all stars become hearts. A lateral swap that can suddenly create winning combinations where none existed.
Split Symbols / xSplit / Splitting Symbols / Symbol Divide / Razor Split
A symbol or modifier splits all symbols in its row or reel into two, doubling their count and the ways to win through that position. The split symbol itself often becomes a wild. If split multiple times, symbols display a multiplier. Pioneered by Nolimit City's xSplit mechanic.
Symbol Inject / Symbol Drop / Extra Symbols / Bonus Symbols / Symbol Placement
Additional symbols placed onto the grid that weren't part of the original spin. The game drops extra wilds, scatters, or high-value symbols after the reels stop.
Symbol Removal / Symbol Clear / Symbol Destroy / Strip Symbols / Cosmic Sweep
Certain symbols are stripped off the grid entirely. Removes low-value or non-winning symbols to increase the concentration of winning symbols. Often paired with cascading reels where removed symbols create space for new ones.
Not Bomb Wilds — Remove Symbols passively strips specific symbol types from the grid. Bomb Wilds are wild symbols that actively explode adjacent symbols and typically carry a growing multiplier.
Mystery Stack / Secret Symbols / Unknown Symbols / ? Symbols / Reveal Symbols / xWays
Special placeholder symbols that all simultaneously reveal as the same randomly chosen regular symbol. Every mystery symbol on the grid reveals identically. Creates large groups of matching symbols from uncertain positions. The basis of Nolimit City's xWays mechanic.
Not Mystery Feature — Mystery Symbols are placeholder symbols that all reveal the same random symbol simultaneously. Mystery Feature is a random bonus event that could trigger any kind of enhancement.
Mega Symbols / Giant Symbols / Oversized Symbols / Big Symbols / 2x2 Symbols / 3x3 Symbols / Super Symbols
Oversized symbols occupying multiple grid positions (2×2, 3×3, or larger). Each cell they occupy counts as a separate instance, dramatically increasing win potential across multiple paylines or ways.
Not Colossal Reels — Colossal Symbols are oversized symbols (2×2, 3×3) covering multiple positions on one grid. Colossal Reels is a second full reel set that mirrors or interacts with the main grid.
Full Stacks / Symbol Stacks / Stacked Regulars / Full Reel Symbol
Non-wild regular symbols appearing in full stacks covering an entire reel. When a full stack lands in view, that reel shows only one symbol type, creating strong multi-payline wins. The non-wild counterpart to Stacked Wilds.
Not Stacked Wilds — Stacked Symbols are regular paying symbols in full stacks. Stacked Wilds are wild substitutes in stacks that can substitute for other symbols.
Multiplier Values / Symbol Multipliers / Multiplier Icons / Multiplier Positions
Non-wild symbols carrying a multiplier value. When they participate in a win or occupy specific positions, they multiply the payout. Often accumulate or double during tumble/cascade sequences. Distinct from Multiplier Wilds.
Not Multiplier Wilds — Multiplier Symbols are non-wild symbols that carry a multiplier value. Multiplier Wilds both substitute and multiply.
Locked Cells / Extra Cells / Bonus Cells / Hidden Positions / Enhancer Positions / Modifier Cells
Extra grid positions above, below, or beside the main reel area that start locked. They unlock when specific conditions are met (wilds landing, scatters appearing, bonus activation) and reveal special symbols — wilds, multipliers, mystery symbols, xWays, or split modifiers. They expand the effective grid when active and inject modifiers. Pioneered by Nolimit City, now widely adopted.
Not Expanding Reels — Enhancer Cells are hidden positions that unlock conditionally to reveal modifiers (wilds, multipliers, splits). Expanding Reels add standard rows with regular symbols at feature start.
Notes
Classification decisions and provider-specific conventions.
'Avalanche' is treated as an alias of Cascading Reels / Tumbles. Different providers use different names for the same mechanic.
'Hold & Respin' is kept separate from generic 'Re-Spins' because it is a distinct bonus structure with its own locking/respin loop.
'X Bet' is classified under Multipliers rather than Buy Features because it modifies the ongoing bet amount rather than purchasing a one-time event.
'Multi-Game Link' covers shared jackpot pools across different game titles, including wide-area progressives spanning multiple casinos.
'Feature Buy' remains in Bonuses & Features (not Buy Features) because it is the original and most common buy mechanic, tightly coupled with bonus activation. Buy Features covers specialized purchase variants.
Buy Features were given their own category because the number and specificity of buy mechanics has grown beyond what fits under Bonuses & Features or Risk Enhancers.
'Enhancer Cells' is placed under Symbol Modifiers because their primary function is injecting modifier symbols into the grid, even though they also expand the playable area.
'Side Reel' is placed under Reel Mechanics because it is a physical reel structure, even though it delivers symbol modifiers.
Nolimit City's 'xSeries' mechanics (xNudge, xWays, xSplit, xBomb, xPays, xBet, xBizarre, xHole) have been genericized into provider-neutral labels. Branded names appear as aliases for search/matching.
Hacksaw Gaming's 'Hackways' is treated as an alias of Megaways — functionally equivalent variable-ways mechanic under a different brand.
A single game can reference items from many categories. A cascading cluster game with progressive multipliers, free spins, sticky wilds, and tiered feature buy would reference six+ categories.
Aliases are for search, import mapping, and display only. The mechanics array in game metadata must always use canonical labels, never aliases.
If you want stricter consistency, store only labels in game JSON and resolve to names/aliases via this taxonomy.
Notes
Classification decisions and provider-specific conventions.
'Avalanche' is treated as an alias of Cascading Reels / Tumbles. Different providers use different names for the same mechanic.
'Hold & Respin' is kept separate from generic 'Re-Spins' because it is a distinct bonus structure with its own locking/respin loop.
'X Bet' is classified under Multipliers rather than Buy Features because it modifies the ongoing bet amount rather than purchasing a one-time event.
'Multi-Game Link' covers shared jackpot pools across different game titles, including wide-area progressives spanning multiple casinos.
'Feature Buy' remains in Bonuses & Features (not Buy Features) because it is the original and most common buy mechanic, tightly coupled with bonus activation. Buy Features covers specialized purchase variants.
Buy Features were given their own category because the number and specificity of buy mechanics has grown beyond what fits under Bonuses & Features or Risk Enhancers.
'Enhancer Cells' is placed under Symbol Modifiers because their primary function is injecting modifier symbols into the grid, even though they also expand the playable area.
'Side Reel' is placed under Reel Mechanics because it is a physical reel structure, even though it delivers symbol modifiers.
Nolimit City's 'xSeries' mechanics (xNudge, xWays, xSplit, xBomb, xPays, xBet, xBizarre, xHole) have been genericized into provider-neutral labels. Branded names appear as aliases for search/matching.
Hacksaw Gaming's 'Hackways' is treated as an alias of Megaways — functionally equivalent variable-ways mechanic under a different brand.
A single game can reference items from many categories. A cascading cluster game with progressive multipliers, free spins, sticky wilds, and tiered feature buy would reference six+ categories.
Aliases are for search, import mapping, and display only. The mechanics array in game metadata must always use canonical labels, never aliases.
If you want stricter consistency, store only labels in game JSON and resolve to names/aliases via this taxonomy.
Notes
Classification decisions and provider-specific conventions.
'Avalanche' is treated as an alias of Cascading Reels / Tumbles. Different providers use different names for the same mechanic.
'Hold & Respin' is kept separate from generic 'Re-Spins' because it is a distinct bonus structure with its own locking/respin loop.
'X Bet' is classified under Multipliers rather than Buy Features because it modifies the ongoing bet amount rather than purchasing a one-time event.
'Multi-Game Link' covers shared jackpot pools across different game titles, including wide-area progressives spanning multiple casinos.
'Feature Buy' remains in Bonuses & Features (not Buy Features) because it is the original and most common buy mechanic, tightly coupled with bonus activation. Buy Features covers specialized purchase variants.
Buy Features were given their own category because the number and specificity of buy mechanics has grown beyond what fits under Bonuses & Features or Risk Enhancers.
'Enhancer Cells' is placed under Symbol Modifiers because their primary function is injecting modifier symbols into the grid, even though they also expand the playable area.
'Side Reel' is placed under Reel Mechanics because it is a physical reel structure, even though it delivers symbol modifiers.
Nolimit City's 'xSeries' mechanics (xNudge, xWays, xSplit, xBomb, xPays, xBet, xBizarre, xHole) have been genericized into provider-neutral labels. Branded names appear as aliases for search/matching.
Hacksaw Gaming's 'Hackways' is treated as an alias of Megaways — functionally equivalent variable-ways mechanic under a different brand.
A single game can reference items from many categories. A cascading cluster game with progressive multipliers, free spins, sticky wilds, and tiered feature buy would reference six+ categories.
Aliases are for search, import mapping, and display only. The mechanics array in game metadata must always use canonical labels, never aliases.
If you want stricter consistency, store only labels in game JSON and resolve to names/aliases via this taxonomy.