Every slots term, defined
Plain definitions for the words you meet on a paytable, a bonus page or a regulator's notice. Each links to the deeper page where there is one.
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- 1,024 ways
- The ways-to-win format on a five-reel, four-row grid: 4 × 4 × 4 × 4 × 4 = 1,024 possible ways.
- 243 ways
- The ways-to-win format on a five-reel, three-row grid: 3 × 3 × 3 × 3 × 3 = 243 possible ways.
A
- Affiliate
- A website or marketer paid by casinos for referring new customers, usually through tracked links.
- Age verification
- The checks a GB-licensed operator must complete to confirm you are 18 or over before you can gamble or play free demos.
- Aggregator
- A platform that bundles games from many providers so a casino can offer them all through one integration.
- Ante bet
- An optional extra stake on each spin that raises the chance of triggering the bonus round.
- Autoplay
- A setting that spins a slot automatically for a chosen number of rounds; banned on GB-licensed online slots since 31 October 2021.
- Avalanche
- NetEnt's name for cascading reels, where symbols fall into place and winning ones explode to let new ones drop.
B
- Bankroll
- The money you set aside for gambling, which should only ever be money you can afford to lose.
- Base game
- The ordinary spins of a slot outside any bonus feature, where you pay a stake for each spin.
- Bet level
- The number of coins bet per line or per spin, multiplied by the coin value to set the stake.
- Bonus buy
- Paying a fixed price, usually a multiple of the stake, to go straight into a slot's bonus round. Not offered on GB-licensed sites.
- Bonus funds
- Money credited by a casino as part of a promotion, which can be played with but not withdrawn until its terms are met.
- Bonus round
- A special feature inside a slot, triggered during play, that plays differently from the base game and often pays more.
- Bonus symbol
- A symbol whose job is to trigger a bonus round, usually by landing a set number in view or on particular reels.
- Branded slot
- A slot built around licensed content such as a TV show, film, band or game show.
C
- Cascading reels
- A mechanic where winning symbols disappear and new ones drop into their place, allowing several wins from one spin.
- Cash on reels
- Symbols that display a cash value or a multiple of the stake directly on the reels, paid when a feature collects them.
- Cashable bonus
- A bonus whose amount becomes withdrawable cash once its wagering is complete, unlike a sticky bonus that is removed on withdrawal.
- Category B machine
- The higher-stake gaming machine categories under the Gambling Act 2005, found in casinos, betting shops, bingo halls and adult gaming centres.
- Category C machine
- The gaming machine category that covers typical pub fruit machines, also found in arcades, bingo halls and clubs.
- Category D machine
- The lowest-stake gaming machine category, including coin pushers and crane grabs found in family arcades.
- Certification
- Formal confirmation from an approved test house that a specific game version meets a regulator's technical standards.
- Classic slot
- A slot styled after traditional machines: usually three reels, a few paylines and symbols such as fruit, bars, bells and sevens.
- Cluster pays
- A win system that pays for groups of matching symbols touching each other horizontally or vertically, anywhere on the grid.
- Coin value
- The cash value of one betting coin on games that build the stake from coins, lines and levels.
- Colossal symbols
- Oversized symbols that cover a block of positions, such as 2x2 or 3x3, and count as that symbol in every position they cover.
- Credit card ban
- Since 14 April 2020, GB-licensed operators cannot accept credit cards for gambling, including slots.
D
- Dead spin
- A spin that pays nothing at all.
- Demo mode
- Playing a slot with virtual credits instead of money; on GB-licensed sites you must be age-verified first.
- Deposit limit
- A cap you set on how much you can deposit into a gambling account over a day, week or month.
E
- Expanding wild
- A wild that grows to cover its whole reel when it lands or is part of a win.
- Expected value (EV)
- The average result per spin over the long run; on a slot it is negative and equals the stake times the house edge.
F
- Feature board
- The illuminated area above a fruit machine's reels showing a trail of features and prizes that can be climbed during play.
- Five-reel slot
- A slot with five reels, the standard layout for video slots, usually with three or four rows.
- Fixed jackpot
- A jackpot of a set size, usually a fixed multiple of the stake, that does not grow with play.
- Free spins (feature)
- A bonus round of spins played at no extra cost at the stake that triggered it, usually with added features.
- Free spins offer
- A casino promotion giving a set number of spins on a named slot at a fixed stake, with any winnings subject to terms.
- Fruit machine
- The British name for a slot machine, especially the pub and arcade type with fruit symbols, nudges, holds and feature boards.
G
- Gamble feature
- An optional step after a win that lets you risk it on a guess, such as card colour, to double it or lose it.
- GamCare
- A charity offering free support, information and treatment for anyone affected by gambling, and operator of the National Gambling Helpline.
- Game cycle
- The regulatory unit of play on a GB online slot: one stake through to its result, which must take at least 2.5 seconds.
- Game provider
- The studio that designs and supplies slot games to casinos, including their maths, art and RNG integration.
- Game round
- Everything that follows a single paid stake, including cascades, respins and any feature it triggers, until the result settles.
- Game weighting
- The percentage of a stake on a given game that counts towards a bonus's wagering requirement.
- GAMSTOP
- The free national self-exclusion scheme that blocks you from every GB-licensed online gambling site for 6 months, 1 year or 5 years.
- Grid slot
- A slot played on a larger grid, often 6x6 or 7x7, where wins usually come from clusters rather than lines.
H
- High roller
- A player who stakes large amounts; casinos often target them with VIP schemes, now closely regulated in Great Britain.
- High-paying symbol
- One of the themed symbols that pay the most for a line or way, and appear less often than low payers.
- Hit frequency
- The proportion of spins that return any win at all, usually written as a percentage or as one win in so many spins.
- Hit rate (bonus hit rate)
- How often, on average, a slot's bonus feature is triggered, usually quoted as one in so many spins.
- Hold
- A fruit machine option that keeps one or more reels in place on the next spin while the others spin again.
- Hold and win
- A bonus where cash or coin symbols lock in place and respins reset each time a new one lands, often with fixed jackpots.
- House edge
- The share of each stake a slot is built to keep over the long run: 100% minus its RTP.
- HTML5
- The web technology modern online slots are built with, letting one game run in any browser on desktop or mobile.
I
- Infinity Reels
- A mechanic where every win adds a new reel to the right, so the grid keeps growing for as long as wins continue.
J
- Jackpot contribution
- The share of each stake that is added to a progressive jackpot pot, and so counts as part of the game's RTP.
L
- LCCP (Licence Conditions and Codes of Practice)
- The Gambling Commission's main rulebook for licensees, setting conditions on fairness, safer gambling, marketing and more.
- LDW (loss disguised as a win)
- A spin that pays back less than was staked but is presented like a win; a net loss with win-style sounds or animation.
- Liberty Bell
- The three-reel slot machine built by Charles Fey in San Francisco around the 1890s, widely regarded as the first true slot machine.
- Local jackpot
- A progressive jackpot fed only by stakes on one game or within one casino, rather than a shared network.
- Loss limit
- A cap on how much you can lose, net of wins, over a set period, after which play is stopped.
- Low stakes
- Playing slots at small stakes per spin, such as a few pence; this lowers the cost per spin but not the house edge.
- Low-paying symbol
- The commonest regular symbols, often card ranks from 10 to A, which pay the smallest amounts.
M
- Max bet rule
- A bonus term limiting the stake per spin while a bonus is active; breaking it can void the bonus and its winnings.
- Max win
- The largest amount a slot can pay on one game round, usually shown as a multiple of the stake.
- Megaways
- A reel mechanic created by Big Time Gaming in which the symbols per reel change every spin, giving up to 117,649 ways to win.
- Mixed-product promotion
- An offer requiring play on one gambling product to unlock a reward on another, such as casino spins for a sports bet; banned in GB since 19 January 2026.
- Mobile slot
- A slot played on a phone or tablet, either in a browser or in a casino app; nearly all modern slots are built to run on mobile.
- Money collect
- A mechanic where a collector symbol gathers the cash values shown on other symbols in view and pays their total.
- Money Honey
- Bally's 1963 machine, the first electromechanical slot with a bottomless hopper that could pay out large amounts automatically.
- Multiplier
- A feature that multiplies a win by a set factor, such as 2x or 10x, sometimes growing during a bonus.
- Must-drop jackpot
- A progressive jackpot guaranteed to be won before a set time or before it reaches a set amount.
- Mystery symbols
- Placeholder symbols that all turn into the same randomly chosen symbol after the reels stop.
N
- National Gambling Helpline
- Free, 24-hour confidential support for anyone affected by gambling, run by GamCare on 0808 8020 133.
- Near miss
- A losing result that looks close to a big win, such as two jackpot symbols with the third just off the line.
- Net position
- Your overall result in a session, wins minus stakes; GB-licensed online slots must display it during play.
- Networked jackpot
- A progressive jackpot shared across many casinos, all contributing to and able to win the same prize pool.
- No-deposit bonus
- A small bonus or set of free spins given on registration without needing a deposit, always with terms and usually a winnings cap.
- Nudge
- A fruit machine feature that lets you move a reel one position, usually down, to try to complete a winning line.
O
- One-armed bandit
- An old nickname for a slot machine, from the side lever used to start the reels and the money it took.
- Operating licence
- The Gambling Commission licence a business needs to offer gambling to people in Great Britain.
- Operator
- The licensed business that runs a casino and holds your account, as opposed to the studio that makes the games.
P
- Pay anywhere
- A win system that pays when enough of the same symbol lands anywhere on the screen, with no lines or adjacency needed.
- Payline
- A set path across the reels along which matching symbols must land, usually from the left, to form a win.
- Paytable
- The in-game screen listing what each symbol pays, how features work, the game's rules and its RTP.
- Pick bonus
- A bonus round where you choose from hidden items to reveal prizes, multipliers or further features.
- Playthrough
- The total amount you must stake to clear a bonus: the bonus amount multiplied by its wagering requirement.
- PRNG (pseudo-random number generator)
- An algorithm that produces a sequence of numbers that behaves as random; the kind of RNG almost every slot uses.
- Progressive jackpot
- A jackpot that grows as a small share of every qualifying stake is added to it, until someone wins it and it resets.
R
- Reality check
- A pop-up reminder that tells you how long you have been playing, and often what you have won or lost, at intervals you set.
- Reel
- A vertical column of symbols that spins and stops to show the result; most video slots have five.
- Reel strip
- The full sequence of symbols on one reel, from which the visible symbols are drawn on each spin.
- Remote gambling
- Gambling done through the internet, phone, TV or other remote communication, as opposed to in a venue.
- Respin
- A further spin, usually free, in which some reels or symbols are held while others spin again.
- Retrigger
- Landing the trigger symbols again during a free spins round to win additional spins.
- Return
- The amount a spin or session pays back, including the original stake; a return can be smaller than the money staked.
- Reverse withdrawal
- Cancelling a pending withdrawal to put the money back into play; GB operators were barred from allowing it from 31 October 2021.
- RNG (random number generator)
- The software that produces the random numbers deciding every slot outcome, independently of previous spins.
- Row
- A horizontal line of symbol positions across the reels; a 5x3 slot has five reels and three rows.
- RTP (return to player)
- The share of all money staked on a slot that it is designed to pay back over the very long run, shown as a percentage.
- RTP range (variable RTP)
- Many slots come in several certified RTP versions, and each casino chooses which one to run.
- RTS (Remote Technical Standards)
- The Gambling Commission's technical rules for online gambling software, covering fairness, RNGs, game information and design.
S
- Scatter
- A symbol that pays or triggers a feature wherever it lands, without needing to be on a payline.
- Seed
- The amount a progressive jackpot starts from after it is won; also the starting value for a PRNG.
- Self-exclusion
- A request to be barred from gambling with an operator, or a group of operators, for a set period.
- Session
- One continuous period of play, from logging in or starting a game to stopping.
- Slam stop
- Pressing the spin button again to stop the reels early; banned on GB-licensed online slots since 31 October 2021.
- Spin
- One play of a slot: the stake is taken, the RNG sets the result and the reels show it.
- Split symbols
- A single symbol position showing two (or more) copies of a symbol, counting as each copy for wins.
- Stacked symbols
- Runs of the same symbol placed together on a reel strip, so the symbol can fill several positions on a reel at once.
- Stake
- The amount of money you bet on a single spin or game round.
- Stake limit
- The legal maximum stake per spin on GB online slots: £5 for players aged 25 and over, £2 for those aged 18 to 24.
- Sticky wild
- A wild that stays in place for a number of spins, often for the rest of a feature, instead of disappearing.
- Symbol
- One of the pictures that appear on the reels; matching symbols in the right positions form wins.
- Symbol upgrade
- A feature that converts lower-value symbols into higher-value ones, either on one spin or for the rest of a bonus.
T
- Test house
- An independent laboratory approved by the regulator to test gambling games and RNGs before they can be offered.
- Theoretical return
- The RTP a slot's maths model produces over an effectively infinite number of spins, as opposed to what any player actually gets.
- Three-reel slot
- A slot with three reels, the layout of the original mechanical machines and of most classic-style games.
- Time-out
- A short, chosen break during which you cannot gamble with an operator; it cannot be cancelled early.
- Total bet
- The full amount a single spin costs, covering all lines or ways and any optional extras.
- Tumble
- Pragmatic Play's name for cascading reels: winning symbols are removed and the rest drop down, with new ones filling from above.
- Turbo spin
- A setting that shortened the reel animation to make spins faster; banned on GB-licensed online slots since 31 October 2021.
U
- UKGC (Gambling Commission)
- The regulator that licenses and supervises gambling in Great Britain, including online slots and casino operators.
V
- Variance
- The statistical measure of how far individual slot results scatter around the average; the maths behind the volatility label.
- Video slot
- A slot that shows its reels on a screen rather than physical drums; the format almost all online slots use.
- Virtual reel
- A larger set of numbers mapped onto a reel's visible stops, letting some symbols be far rarer than they look.
- Volatility
- How widely a slot's results swing: low volatility pays small amounts often, high volatility pays rarely but can pay large amounts.
W
- Wagering requirement
- The number of times bonus money must be staked before it can be withdrawn; capped at 10x on GB casino bonuses since 19 January 2026.
- Walking wild
- A wild that moves one position, usually one reel to the left, on each spin until it leaves the grid.
- Ways to win
- A win system that pays matching symbols on adjacent reels from the left in any row, instead of along fixed lines.
- Welcome bonus
- A promotion for new customers, usually bonus funds or free spins on a first deposit, with terms attached.
- Wheel bonus
- A bonus where a prize wheel is spun to award a cash amount, a multiplier, a jackpot or entry to another feature.
- White label
- A casino brand run on another company's platform and licence, with the licensee responsible to the regulator.
- Wild
- A symbol that stands in for other symbols to complete wins, usually except scatters and bonus symbols.
X
- xWays
- A Nolimit City mechanic where a special symbol expands into several copies of the same symbol, multiplying the ways to win.