Casino Glossary
Every term you will meet when choosing and playing at a UK online casino, in plain English. If a casino's small print loses you, it is probably defined here.
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Affordability check
A light financial-risk check applied above a £150 net monthly loss, with enhanced checks for higher spenders. See affordability checks.
Deposit limit
A cap you set on how much you can pay in over a day, week or month. Available at every UK casino; the simplest way to stay in control.
Fund protection
The level of safeguarding applied to customer balances (Basic, Medium or High). UK casinos must disclose it and remind you every six months.
GAMSTOP
The free UK national self-exclusion scheme that blocks you from all UKGC-licensed online gambling for a chosen period. See GAMSTOP and self-exclusion.
House edge
The casino's built-in mathematical advantage on a game, the inverse of RTP. It is why a casino profits over time even though its games are fair.
IBAS
The Independent Betting Adjudication Service — a free, approved body that resolves disputes between players and casinos when they cannot be settled directly.
Live casino
Games streamed from a real studio with a human dealer — roulette, blackjack, baccarat and game shows — played in real time. See best live casino sites.
Online casino
A website or app licensed to offer real-money casino games — slots, live dealer and table games — to players. In the UK every legal one must hold a UK Gambling Commission licence.
Payout speed
How quickly a casino pays a withdrawal once you are verified. The best pay within 24 hours; e-wallets are usually fastest. See fast payout casinos.
Progressive jackpot
A jackpot that grows as players stake across many casinos until someone wins it, sometimes reaching millions. See jackpot casinos.
RNG
Random number generator — the certified software that produces an unpredictable result for each spin or hand. At licensed casinos it is independently tested and cannot be altered by the casino.
RTP
Return to Player — the percentage of stakes a game returns over the long run. A 96% RTP game returns £96 per £100 staked on average; the remainder is the house edge. Higher is fairer. See highest RTP casinos.
Self-exclusion
A tool that blocks you from a casino (or, via GAMSTOP, all UK casinos) for a set period. A key safeguard if gambling stops being fun.
Stake limit
The statutory cap on online slot stakes: £5 per spin for over-25s, £2 for 18–24-year-olds, in force since 2025.
UKGC
The UK Gambling Commission — the statutory regulator that licenses and supervises all gambling in Great Britain. Check any casino's licence on its register before you play.
UKGC licence
Authorisation from the UK Gambling Commission to offer gambling in Great Britain. It requires fund protection, tested games and identity checks. Always confirm a casino's licence on the public register before playing.
Verification (KYC)
The "know your customer" check every UK casino must run to confirm your identity and age before you can withdraw. Usually quick if your details are accurate. See verification explained.
Volatility
How a game pays: high-volatility games pay larger amounts less often; low-volatility games pay smaller amounts more frequently. It does not change the long-run RTP.
Wagering requirement
The number of times you must stake a bonus before winnings can be withdrawn. A £50 bonus at 10x needs £500 of stakes. Lower is better.
Welcome offer
The reward a casino gives new players on a qualifying deposit — usually free spins or a matched deposit. A factor in our ratings, but never the headline.