Casino Glossary — Every Gambling Term Explained

Whether you’re new to online casinos or just encountered a term you don’t recognise, this glossary covers every gambling term you’re likely to come across. All definitions are written in plain English with practical context so you actually understand what each term means for your money.

A

Account Verification — See KYC. The process of confirming your identity before a casino allows withdrawals. Typically requires a photo ID, proof of address, and proof of payment method.

Active Payline — A line across the reels of a slot machine on which a winning combination can land. Modern slots can have anywhere from 1 to over 100,000 paylines (or “ways to win”).

Affiliate — A website or individual that promotes online casinos in exchange for a commission on referred players. RollBat is a casino affiliate — we earn commissions when you sign up through our links, which we disclose in our affiliate disclosure.

All-In — Betting your entire remaining balance on a single wager. Common in poker; generally inadvisable in casino games.

Alt (Alternative Dispute Resolution / ADR) — An independent third party that mediates disputes between players and casinos. Licensed casinos are required to offer ADR as an escalation path.

Autoplay — A slot feature that automatically spins the reels a set number of times at your chosen bet level. Some jurisdictions (like the UK) have restricted or banned autoplay features.

B

Baccarat — A card game where you bet on whether the “Player” or “Banker” hand will be closest to 9. One of the lowest house edge games in the casino (around 1.06% on Banker bets).

Bankroll — The total amount of money you’ve set aside specifically for gambling. Proper bankroll management means never betting more than a small percentage of your total bankroll on any single wager.

Bet Max — A button on slot machines that automatically places the maximum allowed bet. During bonus wagering, be careful — most casinos cap your bet at €5 per spin while a bonus is active.

Blackjack — A card game where the goal is to get closer to 21 than the dealer without going over. With basic strategy, the house edge can be as low as 0.5%.

Bonus Abuse — A vaguely defined term in casino T&Cs that covers behaviours like creating multiple accounts to claim bonuses, using low-risk strategies to clear wagering, or coordinating with other players. Casinos use this clause to void bonuses they consider exploitative.

Bonus Buy — A slot feature that lets you pay a premium (usually 80-100x your bet) to instantly trigger the bonus round instead of waiting for it to hit naturally. Banned in some jurisdictions including the UK.

Bonus Round — A special feature within a slot game triggered by landing specific symbols (usually Scatters). Typically awards free spins, multipliers, or pick-and-win games with higher win potential than the base game.

Bust — In blackjack, going over 21. If you bust, you lose your bet immediately regardless of what the dealer has.

C

Card Counting — A blackjack strategy that tracks which cards have been dealt to estimate the composition of remaining cards. Effective in land-based casinos but virtually impossible online due to continuous shuffling.

Cascading Reels — A slot mechanic where winning symbols are removed and new symbols fall into their place, potentially creating chain reactions of wins from a single spin. Also called “Avalanche,” “Tumble,” or “Cluster” mechanics.

Cashback Bonus — A bonus that returns a percentage of your net losses over a specific period. For example, 10% weekly cashback means if you lose €500 in a week, you get €50 back. See our casino bonus types guide for more.

Cashout — See Withdrawal.

Cold Streak — An extended period of losing results. Despite how it feels, cold streaks are a normal part of statistical variance and don’t indicate that a game is “due” to pay out.

Contribution Rate — See Game Weighting.

Crash Game — A game type where a multiplier increases from 1x and can “crash” at any random moment. Players must cash out before the crash to win. Learn more in our crash games guide.

Cryptocurrency Casino — An online casino that accepts deposits and withdrawals in Bitcoin, Ethereum, or other cryptocurrencies. Often features faster payouts and lower fees. See our fastest crypto casinos list.

Curaçao Licence — A gambling licence issued by the Government of Curaçao. Less stringent regulatory requirements than MGA or UKGC, though the jurisdiction has been tightening standards.

D

Dealer — The person (or software) that manages the game, deals cards, and enforces rules. In live casino games, this is a real human streamed via video.

Demo Mode — Playing a casino game with fake/virtual credits instead of real money. Also called “free play” or “practice mode.” Useful for testing games before betting real money.

Deposit Bonus — A bonus awarded when you deposit money. The most common type is a “match bonus” — e.g., “100% up to €200” means the casino matches your deposit euro for euro up to €200.

Deposit Limit — A responsible gambling tool that caps how much you can deposit over a set period (daily, weekly, or monthly). Decreases take effect immediately; increases have a mandatory cooling-off period.

Double Down — In blackjack, doubling your bet and receiving exactly one more card. A powerful move when the odds strongly favour you.

Drop — The total amount of money deposited or exchanged for chips at a table or casino over a given period.

E

eCOGRA — eCommerce Online Gaming Regulation and Assurance. An independent testing agency that audits online casinos for fairness, responsible conduct, and player protection.

Edge — See House Edge.

Even Money — A bet that pays 1:1. If you bet €10 and win, you get €10 in profit plus your original €10 back.

Expanding Wild — A Wild symbol in a slot that expands to cover an entire reel when it lands, substituting for all other symbols on that reel.

F

Fair Play — The principle that casino games produce genuinely random, unmanipulated outcomes. Licensed casinos must have their games tested by independent labs to verify fairness.

Fixed Jackpot — A jackpot with a set, unchanging prize amount. Contrast with Progressive Jackpot, which grows over time.

Free Spins — Bonus spins on a slot machine that don’t cost you anything. Can be awarded as part of a welcome bonus, a reload promotion, or triggered within a game’s bonus round. Free spins from promotions usually have their own wagering requirements.

Fruit Machine — A traditional term for slot machines, originating from the fruit symbols (cherries, lemons, oranges) used on early mechanical slots. Still commonly used in the UK.

G

Gambler’s Fallacy — The incorrect belief that past results influence future outcomes in games of chance. If a roulette wheel lands on red 10 times in a row, the probability of red on the next spin is still 48.6%. Each spin is independent.

Game Show — A category of live casino game hosted by a presenter, combining elements of game shows with gambling. Popular titles include Crazy Time, MONOPOLY Live, and Deal or No Deal. See our best live casino game shows ranking.

Game Weighting — How much different games contribute toward clearing wagering requirements. Slots typically count 100%, while table games count 10-20%. Also called “contribution rate.” A critical factor in bonus value — see our wagering requirements guide.

GGR (Gross Gaming Revenue) — The total amount wagered by players minus the total amount won. This is how casinos measure their revenue.

H

High Roller — A player who bets significantly larger amounts than average. Also called a “whale.” Many casinos offer VIP programmes with dedicated account managers, higher withdrawal limits, and exclusive bonuses for high rollers.

Hit — In blackjack, requesting another card from the dealer.

Hit Frequency — How often a slot machine produces a winning combination. A slot with 30% hit frequency pays out on roughly 1 in 3 spins — though most of these “wins” may be less than the original bet.

House Edge — The mathematical advantage the casino has over the player, expressed as a percentage. A 2% house edge means that for every €100 wagered, the casino expects to keep €2 over the long term. Lower is better for the player. Blackjack with basic strategy: ~0.5%. European roulette: 2.7%. Slots: 2-6%.

I

Insurance (Blackjack) — A side bet offered when the dealer’s upcard is an Ace. It pays 2:1 if the dealer has blackjack. Mathematically a bad bet — always decline it.

Instant Withdrawal — A withdrawal processed and received within minutes of the request. Typically available via e-wallets (Skrill, Neteller) or cryptocurrency.

iTech Labs — An independent testing laboratory that certifies the fairness of online gambling games and random number generators.

J

Jackpot — The largest possible prize in a game. Can be fixed (set amount) or progressive (growing over time until won).

Juice — See House Edge. Also called “vig” or “vigorish” in sports betting contexts.

K

KYC (Know Your Customer) — Identity verification required by licensed casinos before processing withdrawals. Typically involves submitting a photo ID (passport, driving licence), proof of address (utility bill, bank statement), and proof of payment method. Required by anti-money laundering regulations.

L

Live Casino — Casino games hosted by real human dealers in a studio, streamed to your device via video. Provides a more authentic casino experience than software-based (RNG) games. Major providers include Evolution and Pragmatic Play Live.

Loss Limit — A responsible gambling tool that caps the maximum amount you can lose in a given period. Once hit, you cannot place further bets until the period resets.

Low Volatility — A slot that pays out frequently but in smaller amounts. Better for extended play sessions and bonus clearing. Contrast with High Volatility. See our slot volatility guide.

M

Martingale — A betting strategy where you double your bet after every loss. Theoretically recovers all losses with one win, but in practice, it rapidly hits table limits or depletes your bankroll during losing streaks. Does not overcome the house edge.

Match Bonus — A bonus where the casino matches your deposit by a percentage. “100% match” means they double your deposit. “200% match” means they triple it. The matched amount is bonus money subject to wagering requirements.

Max Bet Rule — A restriction during bonus wagering that limits the maximum amount you can bet per spin or hand — typically €5. Exceeding this can void your bonus and all winnings. One of the most commonly violated rules. Read more in our casino T&Cs guide.

Max Cashout — See Win Cap.

Megaways — A slot mechanic by Big Time Gaming that produces a different number of symbols on each reel per spin, creating up to 117,649 ways to win. Licensed to many other providers.

MGA (Malta Gaming Authority) — One of the most respected gambling regulators in the world. An MGA licence requires strict player protection standards, fund segregation, and dispute resolution. See our MGA licensed casinos guide.

Multiplier — A feature that multiplies your winnings by a specified factor. A 3x multiplier on a €10 win gives you €30.

N

Natural (Blackjack) — An Ace plus a 10-value card dealt as your first two cards, totalling 21. Also simply called “blackjack.” Typically pays 3:2.

No Deposit Bonus — A bonus awarded without requiring any deposit. Usually small (€5-€20 or 10-50 free spins) with high wagering requirements and a win cap. See our best no deposit bonuses list.

No-Wager Bonus — A bonus with zero wagering requirements. Whatever you win is immediately withdrawable as cash. The most player-friendly bonus type, though typically smaller than standard bonuses.

O

Odds — The probability of a particular outcome occurring, or the ratio of payout to stake. Can be expressed as a percentage, fraction, or decimal.

Over/Under — A type of bet (mainly in sports betting) on whether a total score or value will be above or below a specified number.

P

Payline — See Active Payline.

Payout Percentage — See RTP.

Paytable — The information screen within a slot game showing symbol values, paylines, bonus features, and RTP. Always check the paytable before playing a new slot.

Pending Period — The time between requesting a withdrawal and the casino beginning to process it. During this window, some casinos allow you to cancel the withdrawal and continue playing — a deliberate tactic to encourage you to gamble back your winnings. Better casinos have no pending period.

Progressive Jackpot — A jackpot that grows incrementally as players place bets, with a small portion of each bet contributing to the prize pool. Can reach millions of euros. The jackpot resets to a base amount after being won.

Provably Fair — A cryptographic verification system that lets players independently verify that a game outcome was genuinely random and not manipulated. Common in cryptocurrency casinos. See our provably fair gaming guide.

Push — A tie between the player and the dealer, most commonly in blackjack. Your bet is returned — you neither win nor lose.

R

Reality Check — A responsible gambling feature that notifies you at regular intervals (e.g., every 60 minutes) how long you’ve been playing and how much you’ve won or lost. Required by MGA and UKGC regulations.

Reload Bonus — A bonus offered to existing players on subsequent deposits (after the welcome bonus). Typically smaller than welcome bonuses — e.g., 50% match up to €100.

Responsible Gambling — The principle that gambling should be entertainment, not a way to make money, and that operators must provide tools to help players stay in control. Includes deposit limits, self-exclusion, and reality checks. See our responsible gambling page.

RNG (Random Number Generator) — The software algorithm that determines the outcome of online casino games. Certified RNGs produce statistically random results that cannot be predicted or manipulated. Learn more in our how online slots work guide.

Rollover — See Wagering Requirement.

Roulette — A table game where a ball is spun on a numbered wheel. European roulette (single zero) has a 2.7% house edge; American roulette (double zero) has 5.26%. Always play European.

RTP (Return to Player) — The theoretical percentage of all wagered money a game pays back to players over time. An RTP of 96% means the game returns €96 for every €100 wagered on average. Higher is better. See our highest RTP slots list.

S

Scatter Symbol — A special slot symbol that typically triggers bonus features (like free spins) regardless of its position on the reels. Unlike regular symbols, Scatters don’t need to land on a payline to activate.

Self-Exclusion — A responsible gambling tool that blocks you from accessing your casino account for a chosen period (24 hours to permanent). During self-exclusion, the casino is legally required to prevent you from gambling, depositing, or accessing your account.

Session Limit — A time-based responsible gambling tool that logs you out after a set duration of play.

Side Bet — An optional additional bet alongside the main game. Common in blackjack (Perfect Pairs, 21+3) and baccarat. Side bets almost always have a significantly higher house edge than the main game.

Slot — A casino game with spinning reels and symbol combinations. The most popular game type in online casinos, making up 70-80% of most casinos’ game libraries. See our how online slots work guide.

Soft Hand — In blackjack, a hand containing an Ace counted as 11. Called “soft” because it can’t bust with the next card — the Ace will simply revert to counting as 1.

Split — In blackjack, dividing a pair into two separate hands, each with its own bet. Always split Aces and 8s.

Stake — The amount of money wagered on a single bet or spin.

Stand — In blackjack, keeping your current hand and ending your turn.

Sticky Bonus — A bonus where the bonus amount itself can never be withdrawn — only winnings above the bonus amount. Less common today but still found at some casinos.

Sticky Wild — A Wild symbol that remains in place for multiple spins, typically during a free spins bonus round.

Surrender — In blackjack, forfeiting half your bet to give up your hand before playing. Available at some tables for unfavourable hands (e.g., hard 16 vs dealer 10).

T

Table Limit — The minimum and maximum bet allowed at a specific game table. Online table limits vary widely — from €0.10 to €500,000+ at high-roller live tables.

Terms and Conditions (T&Cs) — The legal rules governing your relationship with the casino. Covers everything from bonus rules to withdrawal procedures to account closure conditions. Always read the bonus-specific terms before claiming. See our how to read casino T&Cs guide.

Tilt — Making emotional, irrational betting decisions — usually after a losing streak. Playing on tilt leads to chasing losses with bigger bets. If you feel tilted, stop playing.

Tournament — A competitive event where players compete against each other (not the house) for prizes by accumulating points, usually from slot play within a set timeframe.

Tumble — See Cascading Reels.

V

Variance — See Volatility. The mathematical measure of how results deviate from the expected average. High variance means bigger swings in both directions.

VIP Programme — A loyalty scheme that rewards regular players with perks like cashback, personal account managers, faster withdrawals, higher limits, and exclusive bonuses. Usually structured in tiers based on wagering volume.

Volatility — A measure of risk in a slot game. High volatility slots pay out less frequently but in larger amounts. Low volatility slots pay more often but in smaller amounts. See our slot volatility explained guide.

W

Wagering Requirement — The number of times you must bet a bonus (or deposit + bonus) before you can withdraw any winnings. A “35x” requirement on a €100 bonus means you must place €3,500 in total bets. The single most important factor in bonus value. See our full wagering requirements guide.

Ways to Win — A slot mechanic that replaces traditional paylines. Matching symbols on adjacent reels from left to right create wins regardless of vertical position. Common formats: 243 ways, 1,024 ways, and Megaways (up to 117,649 ways).

Welcome Bonus — The bonus offered to new players on their first deposit (or first several deposits). Also called a “sign-up bonus” or “first deposit bonus.” See our best welcome bonuses ranking.

Whale — See High Roller.

Wild Symbol — A slot symbol that substitutes for most other symbols to help complete winning combinations. Similar to a joker in card games. Wilds cannot usually substitute for Scatter or Bonus symbols.

Win Cap — A maximum limit on how much you can withdraw from bonus winnings. Common on no-deposit bonuses and free spins (e.g., “maximum cashout €100”). Means that even if you win €10,000 from a bonus, you can only keep the capped amount.

Withdrawal — The process of transferring winnings from your casino account to your personal bank account, e-wallet, or crypto wallet. Also called a “cashout.” Processing times vary by method — see our payment methods guide.

Withdrawal Limit — The maximum amount you can withdraw in a given period (daily, weekly, or monthly). Low withdrawal limits are a casino red flag — reputable casinos set limits of €50,000+/month or have no limits at all.