Casino & Slots Glossary – A to Z of Gambling Terms

A to Z of casino terms

Term	Meaning
Avalanche / cascade	Winning symbols are removed and replaced, allowing more wins from one spin.
Bonus funds	Money credited by a casino that must be wagered before winnings can be withdrawn.
Cluster pays	Wins for groups of matching symbols touching each other.
Expanding wild	A wild that grows to fill its reel.
Free spins	Spins played without using your balance, as a bonus or a slot feature.
GAMSTOP	The free UK self-exclusion scheme for online gambling.
Hit frequency	How often a slot lands any win.
House edge	The casino's average advantage; 100% minus RTP.
Jackpot	A top prize – fixed or progressive.
KYC	"Know your customer" – identity and age verification.
Max bet	The largest stake allowed, by law or bonus terms.
Megaways	A mechanic with a changing number of ways to win on every spin.
No wagering	Winnings are paid as cash with no playthrough.
Paylines	Lines across the reels on which wins are paid.
Progressive jackpot	A jackpot that grows with every bet until won.
RNG	Random number generator – decides every spin.
RTP	Return to player – the long-run percentage of stakes paid back.
Scatter	A symbol that pays anywhere and often triggers features.
Significant terms	The key bonus conditions shown beside an offer.
Tumble	Another name for cascading reels.
UKGC	The UK Gambling Commission, which licenses gambling in Great Britain.
Volatility	How a slot spreads its wins – frequent and small, or rare and large.
Wagering	How many times bonus funds must be played through.
Wild	A symbol that substitutes for others.

For a full guide to bonus conditions, see bonus terms explained and wagering requirements.

Term	Meaning
10x cap	The maximum bonus wagering allowed in the UK since 19 January 2026.
Mixed-product promotion	A bonus requiring play on more than one product – banned since January 2026.
Stake limits	£5 per spin on slots (£2 for 18–24s).
ADR	Alternative dispute resolution – independent complaint handling for licensed casinos.
Safer gambling tools	Deposit limits, time-outs, reality checks and self-exclusion.

Term	Meaning
E-wallet	A digital wallet such as PayPal or Skrill.
Open banking	Paying directly from your bank, as with Trustly.
Visa Fast Funds	Faster card withdrawals for eligible debit cards.
Closed loop	Withdrawals must go back to the method you deposited with.
Pending period	Time before a casino processes a withdrawal request.

Term	Meaning
House edge	The casino's average advantage on a game.
Basic strategy	The mathematically best blackjack decisions.
La Partage	A French roulette rule returning half of even-money bets on zero.
Banker / Player	The two hands you can bet on in baccarat.
Shoe	The container holding several decks of cards.

Term	Meaning
Deposit limit	A cap on how much you can deposit.
Time-out	A short break from your account.
Reality check	An on-screen reminder of time played.
Self-exclusion	Closing your account for a set period.

Term	Meaning
Qualifying stake	The amount you must bet to unlock an offer.
Spin value	The stake value of each free spin, usually 10p.
Max bet	The largest stake allowed while a bonus is active.
Expiry	The time limit to use a bonus or complete wagering.

What does RTP mean?

Return to player – the long-run percentage of stakes a game pays back.

What does KYC mean?

Know your customer – the identity checks casinos must carry out.