Casino glossary
Clear definitions of the terms you meet in casino terms and conditions, game rules and bonus offers.
Short answer
The glossary explains 80 terms from bonuses, games, payments and player safety in plain English, each with an example where numbers matter.
The glossary below lists every term alphabetically with a one-sentence definition; open a term for the full explanation and a worked example wherever numbers matter. Each entry is written for players reading real casino terms, bonus conditions and game rules, not for the industry.
If you are about to sign up somewhere, start with the bonus and payment terms. They decide whether and when you can withdraw, and they are where most player complaints begin. The topic overview after the list groups the most important terms.
A
- Actual return (observed payout)
- Actual return is the payout percentage observed over a specific period or sample, which can differ sharply from a game's theoretical RTP.
- ADR (alternative dispute resolution)
- ADR is an independent service that decides unresolved complaints between a player and a licensed casino without going to court.
- Affiliate
- An affiliate is a website or publisher that refers players to casinos and is paid a commission or fee by the operator for doing so.
- Affordability check
- An affordability check is an operator's assessment of whether your level of gambling spend is sustainable given your income and finances.
- American roulette
- American roulette adds a double zero to the wheel, making 38 pockets and raising the house edge to about 5.26%.
- AML (anti-money laundering)
- AML refers to the legal controls casinos apply to detect and prevent criminal money being moved through gambling accounts.
B
- Bankroll
- A bankroll is the amount of money you set aside for gambling, kept separate from funds needed for living costs, savings or debts.
- Basic strategy (blackjack)
- Basic strategy is the mathematically optimal way to play each blackjack hand, based only on your cards and the dealer's upcard.
- Blacklist
- A casino blacklist is a list of operators flagged for unfair practices, non-payment or operating without a valid licence.
- Bonus abuse
- Bonus abuse is the casino term for using promotions in ways the terms prohibit, such as multiple accounts or banned low-risk betting patterns.
- Bonus balance
- The bonus balance holds promotional funds separately from your real-money balance; it can be played but not withdrawn until conditions are met.
- Bonus buy (feature buy)
- A bonus buy lets you pay a fixed multiple of your stake to trigger a slot's bonus feature immediately instead of waiting for it to occur.
- Bonus code
- A bonus code is a string you enter at registration or deposit to activate a specific promotion; without it, the offer may not apply.
- Bonus expiry
- Bonus expiry is the deadline for claiming, using or completing wagering on a bonus; unfinished bonuses and their winnings are removed afterwards.
C
- Cashback
- Cashback returns a percentage of your net losses over a set period, paid as cash or as bonus funds depending on the terms.
- Chargeback
- A chargeback is a forced reversal of a card or payment transaction, initiated through your bank or payment provider rather than the casino.
- Chasing losses
- Chasing losses means continuing to gamble, often with bigger stakes, in an attempt to win back money already lost.
- Closed-loop policy
- A closed-loop policy requires withdrawals to be paid back to the same method used for deposits, as far as that method allows.
- Cluster pays
- Cluster pays is a slot payout system in which wins come from groups of matching symbols touching each other, not from paylines.
- Cooling-off period (time-out)
- A cooling-off period, or time-out, is a short voluntary break from gambling with an operator, lasting from a day up to several weeks.
- Crash game
- A crash game shows a multiplier rising from 1x until it randomly stops; you receive your stake times the multiplier only if you cash out before it stops.
- Cryptocurrency payment
- A cryptocurrency payment uses a digital currency such as Bitcoin to deposit or withdraw at a casino that accepts it.
D
- Demo mode
- Demo mode lets you play a casino game with virtual credits and no real money, to learn its rules and features.
- Deposit limit
- A deposit limit caps how much money you can add to your casino account per day, week or month.
- Deposit match
- A deposit match adds bonus money equal to a percentage of your deposit, up to a stated maximum amount.
- Dormant account
- A dormant account is a casino account with no activity for a defined period, after which fees or closure may apply under the terms.
E
- E-wallet
- An e-wallet is an online payment account that holds money and transfers it between your bank and merchants such as casinos.
- En prison
- En prison is a roulette rule under which an even-money bet is held for one more spin when zero appears, instead of being lost immediately.
- European roulette
- European roulette uses a wheel with 37 pockets, numbers 1 to 36 plus a single zero, giving a house edge of about 2.70%.
- Expected value (EV)
- Expected value is the average result of a bet if it were repeated many times, calculated by weighting each outcome by its probability.
F
- Free spins
- Free spins are slot rounds funded by the casino at a fixed stake; winnings are often credited as bonus money subject to wagering.
G
- Gambler's fallacy
- The gambler's fallacy is the mistaken belief that past random results make a particular outcome more or less likely next time.
- Game provider
- A game provider is the studio that develops and supplies casino games, which operators then license and offer on their own sites.
- Game weighting
- Game weighting sets how much of each bet counts toward wagering: slots often count 100%, table games much less or nothing at all.
- Gaming licence
- A gaming licence is the official authorisation a regulator grants an operator to offer gambling services, subject to legal and technical conditions.
- GAMSTOP
- GAMSTOP is Great Britain's free national self-exclusion scheme, blocking access to online gambling with every operator licensed there.
- Geo-blocking
- Geo-blocking is the restriction of access to a casino's services based on the user's location, usually detected through the IP address.
H
- High roller
- A high roller is a player who stakes amounts well above the typical range, often with access to higher limits and personal account management.
- Hit frequency
- Hit frequency is the share of spins or rounds that return any win at all, whether or not the win exceeds the stake.
- House edge
- House edge is the average share of each bet the casino expects to keep over the long run, expressed as a percentage of the stake.
I
- Insurance (blackjack)
- Insurance is a blackjack side bet, offered when the dealer shows an ace, that pays 2 to 1 if the dealer has blackjack.
K
- KYC (know your customer)
- KYC is the identity verification a licensed casino must carry out to confirm who you are, your age and your address.
L
- La partage
- La partage is a roulette rule that returns half of each even-money stake to the player when the ball lands on zero.
- Licence number
- The licence number is the unique identifier a regulator assigns to a licence, used to verify an operator in the regulator's public register.
- Live dealer
- Live dealer games stream a real croupier and physical equipment from a studio, with bets placed through an online interface.
- Loss limit
- A loss limit stops you from continuing to play once your net losses over a chosen period reach a set amount.
M
- Max bet (bonus rule)
- The max bet rule limits your stake per spin or hand while a bonus is active; exceeding it can void the bonus and its winnings.
- Max cashout
- Max cashout is the upper limit on how much you can withdraw from winnings generated with a particular bonus or free-spin offer.
- Max win
- Max win is the largest payout a game can produce in one round or feature, usually stated as a multiple of the stake.
- Megaways
- Megaways is a licensed slot mechanic in which the number of symbols on each reel changes every spin, varying the number of ways to win.
- Minimum deposit
- The minimum deposit is the smallest amount a casino accepts in one payment, which may differ by payment method and for bonus eligibility.
N
- No deposit bonus
- A no deposit bonus is a small credit or set of free spins given without requiring a payment, usually with strict wagering and cashout limits.
- Non-sticky bonus
- A non-sticky bonus keeps your real money separate and plays it first, so real-money winnings can be withdrawn before the bonus is touched.
P
- Paylines
- Paylines are fixed patterns across the reels on which matching symbols must land to produce a win in a classic slot.
- Payout limit
- A payout limit caps how much a casino will pay out within a given period, such as per transaction, day, week or month.
- Playthrough
- Playthrough is another name for the wagering requirement: the volume of qualifying bets needed before bonus-linked funds become withdrawable.
- Prepaid voucher
- A prepaid voucher is a code bought with cash or card that funds a casino deposit without sharing bank details with the casino.
- Problem gambling
- Problem gambling is gambling that harms a person's finances, relationships, health or work, ranging from moderate risk to clinical addiction.
- Progressive jackpot
- A progressive jackpot is a prize that grows as a small share of each qualifying bet is added to it, until someone wins it.
- Provably fair
- Provably fair is a cryptographic method that lets players verify after each round that the result was fixed before the bet and not changed afterwards.
R
- Reality check
- A reality check is an on-screen reminder at set intervals that shows how long you have been playing and offers options to stop.
- Regulator
- A regulator is the public authority that licenses gambling operators, sets the rules they must follow and enforces them through audits and sanctions.
- Reload bonus
- A reload bonus is a deposit match offered to existing customers on later deposits, usually smaller than the welcome offer.
- Restricted games
- Restricted games are titles you may not play, or that do not count, while a bonus is active; using them can forfeit the bonus.
- Reverse withdrawal
- A reverse withdrawal lets you cancel a pending payout and return the money to your playable balance.
- RNG (random number generator)
- An RNG is the software that produces unpredictable outcomes for digital casino games, independent of all previous results.
- RTP (return to player)
- RTP is the theoretical percentage of all money staked on a game that is paid back as winnings over a very large number of plays.
S
- Scatter symbol
- A scatter is a slot symbol that pays or triggers a feature wherever it lands, without needing to sit on a payline.
- Self-exclusion
- Self-exclusion is a formal request to be blocked from gambling with an operator, or across a national scheme, for a fixed period of months or years.
- Source of funds
- A source of funds check asks you to prove where the money you gamble with comes from, such as salary, savings or an inheritance.
- Sportsbook
- A sportsbook is the betting section of an operator where you place wagers on sports and other events at odds set by the bookmaker.
- Sticky bonus
- A sticky bonus can be used for betting but never withdrawn itself; its amount is deducted from your balance when you cash out.
T
- Terms and conditions
- Terms and conditions are the contract between you and the casino, setting the rules for accounts, bonuses, payments and disputes.
V
- VIP programme
- A VIP programme is a tiered loyalty scheme that rewards players with benefits based on how much they stake or lose.
- Volatility (variance)
- Volatility describes how widely results swing around the average: high-volatility games pay rarely but larger amounts, low-volatility games pay often but smaller amounts.
W
- Wager-free bonus
- A wager-free bonus pays its winnings as withdrawable cash straight away, with no requirement to re-stake them first.
- Wagering requirement
- A wagering requirement is the total amount you must stake before bonus funds, or winnings made with them, can be withdrawn as cash.
- Welcome package
- A welcome package is a set of bonuses for new customers, often spread across several deposits with separate terms for each stage.
- Wild symbol
- A wild is a slot symbol that substitutes for other symbols to complete winning combinations, usually excluding scatters and bonus symbols.
- Withdrawal pending
- Withdrawal pending is the status of a payout request that the casino has received but not yet approved and sent.
The most important casino terms by topic
A small set of gambling terms explains most casino rules: bonus conditions, game maths, payments, licensing and player protection. Learn these and you can read almost any set of casino terms with confidence.
Bonus terms
The wagering requirement is the amount you must stake before bonus money becomes withdrawable: a 100 bonus with 35x wagering means 3,500 in stakes. The max bet rule caps your stake while a bonus is active, and max cashout limits what you can withdraw from it. A sticky bonus can never be withdrawn itself, while a non-sticky bonus lets you play with your own money first. Game weighting decides how much each game counts towards wagering.
Game maths
RTP is the share of stakes a game pays back over the long run, and the house edge is the share it keeps. According to the Wizard of Odds, the house edge is 2.70% in single-zero roulette and 5.26% on most bets in double-zero roulette. Volatility describes how unevenly a slot pays, and the RNG is the random number generator behind every digital result.
Payments and withdrawals
KYC is the identity check a casino runs before paying out. A pending withdrawal is waiting for the casino’s approval, and a payout limit caps how much you can withdraw per day, week or month.
Licensing and safety
A gaming licence is issued by a regulator, and its licence number can be checked in the regulator’s register. ADR is the independent complaints route that strong licences require.
Responsible gambling
A deposit limit caps what you can add to your account, a reality check reminds you how long you have played, and self-exclusion blocks your account for a set period or permanently. Set limits before you play, not after a loss.
How to use the casino glossary when reading terms
Read the casino’s terms with the glossary open and look up every term that affects your money. The terms that matter most are the ones that limit withdrawals.
- Find the wagering requirement, max bet and max cashout in the bonus terms.
- Check withdrawal limits and the KYC documents required in the payment terms.
- Look up the regulator and verify the licence number.
Our guide to wagering requirements works through full examples.
Frequently asked questions
What does wagering requirement mean?
A wagering requirement is the total amount you must stake before you can withdraw a bonus and the winnings from it. It is written as a multiple, such as 35x the bonus. With a 100 bonus at 35x, you must place 3,500 in bets first, and some games may count only partly towards that total.
What is the difference between RTP and house edge?
They describe the same thing from opposite sides. RTP is the share of all stakes a game pays back to players over the long run; the house edge is the share the casino keeps. A game with 97.30% RTP has a house edge of 2.70%, which is the figure for single-zero roulette.
What is KYC in a casino?
KYC stands for “know your customer”: the identity and age checks a licensed casino must carry out. You usually provide a photo ID and proof of address, and sometimes proof of your payment method or source of funds. Many casinos complete KYC before your first withdrawal, so uploading documents early avoids delays.
What is a sticky bonus?
A sticky bonus can be played with but never withdrawn itself. When you cash out, the bonus amount is removed and only the winnings above it are paid. A non-sticky bonus works the other way round: you play with your own deposit first, and the bonus only comes into play once that money is used.
Sources: Wizard of Odds: roulette basics