Slot glossary

Short, plain-English definitions of the terms you'll see in slot reviews and paytables. Each entry links to a longer guide or a list of slots that use the feature.

Ante bet
An optional extra stake (often about 25% more per spin) that raises the chance of triggering free spins. It increases the cost of every spin. Learn more →
Avalanche
Thunderkick's and NetEnt's name for tumbling reels: winning symbols disappear and new ones fall into place. Learn more →
Base game
Normal paid spins, outside any bonus feature. Learn more →
Bonus buy
Paying a fixed multiple of your stake to go straight into a bonus round. Banned in some markets, including Great Britain. Learn more →
Bonus frequency
How often the main bonus triggers on average, e.g. 1 in 180 spins. Learn more →
Book slot
A slot where a special symbol expands to cover whole reels during free spins, popularised by Book of Dead. Learn more →
Cascading reels
Another name for tumbling reels – winning symbols are removed and replaced from above. Learn more →
Cluster pays
A pay system where groups of matching symbols touching horizontally or vertically form wins. Learn more →
Collector
A symbol that gathers the values of cash or coin symbols on the grid, common in fishing and hold-and-win games. Learn more →
Demo mode
Playing a slot with play-money credits instead of real money. Official demos run the same rules as the real game. Learn more →
DuelReels
Hacksaw Gaming's expanding wild reels where two characters duel and the winner's multiplier applies to the reel. Learn more →
Expanding wild
A wild that grows to cover a whole reel, often with a multiplier or respin. Learn more →
Feature
Any special event beyond a normal win: free spins, respins, modifiers or pick games. Learn more →
Free spins
A bonus round of spins at no cost, usually triggered by three or more scatter symbols. Learn more →
Gamble feature
An optional double-or-nothing step after a win. You can lose the win entirely. Learn more →
Hit frequency
How often any winning spin lands, e.g. 1 in 4 spins. Includes wins smaller than your stake. Learn more →
Hold and win
A respin feature where coin symbols lock in place and new ones reset a respin counter. Learn more →
House edge
The share of each stake a game keeps over the long run: 100% minus the RTP. Learn more →
Infectious wild
A wild or xWays symbol that spreads its symbol to other positions on the grid. Learn more →
Jackpot (fixed)
A set prize, usually a multiple of your bet, awarded by special symbols or a full grid. Learn more →
Max win
The largest payout a slot allows from one spin or bonus round, as a multiple of your stake. Learn more →
Megaways
Big Time Gaming's mechanic where reel heights change every spin, giving up to 117,649 ways to win. Learn more →
Multiplier
A value that multiplies a win – on a wild, a grid position, a reel or the whole round. Learn more →
Mystery symbol
A symbol that reveals a random symbol, wild or feature after the reels stop. All mystery symbols usually reveal the same thing. Learn more →
Pay anywhere
Also called scatter pays: enough matching symbols anywhere on the grid win, with no lines or adjacency needed. Learn more →
Paylines
Fixed lines across the reels on which matching symbols must land to win. Learn more →
Progressive multiplier
A multiplier that grows with each win or cascade during a feature, often without resetting. Learn more →
Respin
A free re-spin of some or all reels, usually with certain symbols held in place. Learn more →
Retrigger
Extra free spins awarded for landing more scatters during the bonus round. Learn more →
RTP
Return to player: the percentage of all money wagered that a slot is designed to pay back over millions of spins. Learn more →
RTP version
One of several RTP configurations of the same game that providers offer casinos, e.g. 96.5%, 95.5% and 94.5%. Learn more →
Scatter
A symbol that pays or triggers a feature wherever it lands, regardless of lines. Learn more →
Sticky wild
A wild that stays in place for more than one spin. Learn more →
Super Cascades
Hacksaw Gaming's tumble variant that removes every symbol of a winning type, not just the winning group. Learn more →
Tumbling reels
Winning symbols disappear and new ones drop in, so one paid spin can win several times. Learn more →
Volatility
How unevenly a slot pays: high volatility means rarer but bigger wins, low volatility means frequent smaller wins. Learn more →
Walking wild
A wild that moves one position (usually one reel left) on each spin, paying again where it lands. Learn more →
Ways to win
A pay system where matching symbols on adjacent reels pay in any row, e.g. 243 or 4,096 ways. Learn more →
Wild
A symbol that substitutes for other symbols to help complete wins. Learn more →
xBet
Nolimit City's option to pay a higher stake per spin for a better chance of triggering bonuses. Learn more →
xBomb
Nolimit City's exploding wild that clears neighbouring symbols and raises the win multiplier. Learn more →
xNudge
Nolimit City's stacked wild that nudges into view, adding +1 to its multiplier with each step. Learn more →
xSplit
Nolimit City's mechanic that splits symbols in half to double them, often doubling a multiplier too. Learn more →
xWays
Nolimit City's mystery symbol that reveals several copies of one symbol, making the reel taller and adding ways. Learn more →