Casino Terminology Glossary

This is a reference list, not an introduction: terms are grouped by where you meet them, each definition says what the word actually denotes, and every entry has its own link so a single term can be sent to someone.

Where a term has a standard English form that is used untranslated across markets — RTP, wild, scatter — that form is kept. Where the English and the local usage differ, both are given.

Odds and the basics of a bet

Stake — the amount of money placed on a single bet or spin; everything else in a wager is calculated from it.

Odds — the price of a bet, expressed as the payout per unit staked; they imply a probability, with the bookmaker’s margin added on top.

Decimal odds — the format where the number includes your stake: 2.50 returns 2.50 per 1.00 staked, so the profit is 1.50.

Fractional odds — the British format showing profit against stake: 3/2 pays three units of profit for every two staked.

Implied probability — the chance an odds price corresponds to, found by dividing 1 by the decimal odds; summed across a market it exceeds 100 per cent, and the excess is the margin.

Overround (margin) — the amount by which a market’s implied probabilities exceed 100 per cent; this is the bookmaker’s built-in edge.

Accumulator (parlay) — a single bet combining several selections where all must win; the margin compounds with each leg added.

Handicap — a market where one side is given a virtual head start or deficit to even out the contest.

Value bet — a bet whose price is longer than the true probability justifies; it is a judgement about the price, not a prediction of the result.

Closing line — the final price before an event starts; beating it consistently is the usual test of whether a bettor prices better than the market.

Cash out — settling a bet before the event ends for an amount the operator calculates; the offered sum always carries a further margin.

Live betting (in-play) — betting after an event has started, with prices updated continuously and brief suspensions around key moments.

Slots and reel mechanics

Reel — one of the vertical strips of symbols that spin; most modern slots use five, and the number of reels fixes how paylines can run.

Row — a horizontal line of symbol positions across the reels; reels times rows gives the size of the visible grid.

Payline — a fixed path across the reels on which matching symbols pay; the paytable states how many lines a game has.

Ways to win — an alternative to paylines where any matching symbols on adjacent reels pay, regardless of position.

Cluster pays — a mechanic paying for groups of touching identical symbols rather than for lines.

Megaways — a licensed mechanic where the number of symbols per reel changes each spin, so the number of ways to win varies.

Return to player (RTP) — the published share of all stakes a game returns to players over the long run; the remainder is the house edge.

House edge — the operator’s expected share of each stake, equal to 100 per cent minus the return to player.

Volatility (variance) — how a game’s return is distributed: low volatility pays small amounts often, high volatility pays rarely and large.

Hit frequency — how often a spin produces any win at all, which is a separate figure from the return to player.

Wild symbol — a symbol that substitutes for others to complete a winning combination.

Scatter symbol — a symbol that pays or triggers a feature wherever it lands, without needing to be on a payline.

Free spins round — a bonus feature of a slot giving spins at no additional stake; this is a game feature, not a promotional bonus.

Bonus buy (feature buy) — paying a fixed multiple of the stake to enter a bonus round immediately; the buy mode carries its own certified return.

Progressive jackpot — a prize pool fed by a slice of every qualifying stake, often shared across many casinos until someone wins it.

Max win (win cap) — the highest multiple of the stake a game can pay, stated on the information screen.

Paytable — the game’s own information screen listing symbol values, features, the applied return and the testing laboratory.

Random number generator (RNG) — the certified software that draws each result; draws are independent, so past spins carry no information about the next.

Table games

Dealer (croupier) — the person running a table game, dealing cards or spinning the wheel.

Shoe — the box holding several shuffled decks from which cards are dealt.

Hole card — a card dealt face down, visible only to its holder; in blackjack it is the dealer’s second card.

Push — a tied hand where the stake is returned and nothing is won or lost.

Insurance — a side bet in blackjack offered when the dealer shows an ace; it carries its own, worse, house edge.

Surrender — forfeiting half the stake to end a blackjack hand early, where the rules allow it.

Side bet — an optional extra wager on a table game, almost always with a higher house edge than the main game.

Outside bet — in roulette, a bet on a large group such as red, black, odd or even, paying short odds.

Inside bet — in roulette, a bet on one number or a small group of them, paying long odds.

En prison / la partage — French roulette rules that return or halve an even-money stake when zero lands, lowering the house edge.

Banker and player — the two hands in baccarat; both are dealt by the house and the names describe the hands, not the participants.

Sic bo — a dice game in which the house edge differs sharply between bet types on the same table.

Keno, bingo and draw games

Keno — a draw game where you pick numbers from a field, usually 1 to 80, and twenty are drawn.

Spot — one chosen number on a keno ticket; a ten-spot ticket carries ten picks.

Catch — a chosen number that is actually drawn; the paytable pays by how many you catch out of how many you picked.

Keno paytable — the table of prizes by spots picked and numbers caught; returns differ widely between operators, more than in most casino games.

Race (draw) — a single round of keno; in online keno races run back to back without waiting for other players.

Bingo pattern — the shape that must be completed on a card to win, from a single line to the full house.

Full house (blackout) — covering every number on a bingo card, usually the largest prize of a game.

Progressive bingo jackpot — a prize paid when a full house is completed within a set number of calls.

Live casino

Live dealer game — a table filmed in a studio and streamed, with bets placed through the interface rather than with chips.

Game show title — a live format built around a wheel or a presenter, where the return comes from a paytable like any other game.

Betting window — the seconds in which bets are accepted before a live round closes.

Table limits — the minimum and maximum stake a table accepts; live tables usually sit in a narrower band than software games.

Multiplier drop — a feature where random positions are boosted before a round; the boost is already priced into the game’s return.

Bonuses and promotions

Welcome bonus — an offer for a first deposit, usually a percentage match up to a ceiling.

Deposit match — a bonus calculated as a share of the deposit: a 100 per cent match doubles the balance and doubles nothing else.

No-deposit bonus — a small credit given without payment, normally with the tightest withdrawal cap on the site.

Free spins (promotional) — spins granted as a promotion at a fixed stake per spin, so their value is the stake times the count, not the headline number.

Cashback — a share of net losses returned over a period; whether it is wager-free is the clause that decides its worth.

Reload bonus — a repeat deposit offer for existing accounts, usually at a lower percentage than the welcome offer.

Loyalty programme — a tier system awarding points for turnover; the conversion rate from points to money is the only figure that matters.

Bonus code — a string that must be entered for an offer to apply; without it the deposit is usually processed without the bonus.

Wagering and bonus mechanics

Wagering requirement — the turnover needed before bonus funds can be withdrawn, written as a multiple such as 35×.

Wagering base — what that multiple applies to; 35× on deposit plus bonus is twice the turnover of 35× on the bonus alone.

Game contribution (weighting) — the share of a stake that counts towards wagering, commonly 100 per cent on slots and 10 per cent or less on live tables.

Maximum bet with a bonus — the per-spin cap while a bonus is active; exceeding it once is among the most common grounds for voiding winnings.

Maximum cashout — a ceiling on what can be withdrawn from a bonus, often expressed as a multiple of the bonus.

Sticky bonus — a bonus that cannot itself be withdrawn: it is removed from the balance when a withdrawal is made.

Non-sticky bonus — a structure keeping cash and bonus as separate balances, so the cash stays withdrawable at the cost of losing the bonus.

Bonus expiry — the window in which wagering must be completed, after which the bonus and any winnings from it are removed.

Excluded games and providers — titles or studios on which bonus funds may not be used, or which contribute nothing to wagering.

Bonus abuse — patterns an operator treats as exploiting an offer, such as low-risk opposing bets, and which can void the bonus.

Payments and verification

E-wallet — an intermediary payment account used to fund gambling accounts, usually faster on withdrawal than a bank transfer.

Minimum deposit — the smallest payment an operator accepts, and often also the threshold that qualifies for an offer.

Pending period — the time a withdrawal sits before processing, during which it can usually be reversed back into the balance.

Reverse withdrawal — cancelling a pending withdrawal to play with the money again; where it exists, it is the clause that most often turns a win back into a loss.

Know your customer (KYC) — the identity and address checks a licensed operator must complete, normally requested at the first withdrawal.

Source of funds check — additional documentation of where money came from, requested above certain thresholds or on unusual patterns.

Chargeback — reversing a card payment through the bank; it is not available for most crypto payments and usually closes the account.

Currency conversion — the spread applied when the account currency differs from the payment currency, charged on both directions.

Responsible gambling

Deposit limit — a cap on what can be paid in over a chosen period; increases take effect with a delay, which is what makes it work.

Loss limit — a cap on net losses in a session or period, after which play stops.

Session time limit — a cap on how long a single session may run.

Reality check — a recurring on-screen reminder of elapsed time and amounts staked.

Cooling-off period — a short self-imposed break during which the account cannot be used.

Self-exclusion — a longer, enforced block on the account that cannot be lifted on request before it expires.

Loss chasing — raising stakes to recover a loss; the behaviour most consistently associated with gambling harm.

Gambler’s fallacy — the belief that an outcome is due because it has not appeared recently; in independent draws the past changes nothing.

Types of casino and licensing

Licensed operator — a site holding a gambling licence from a named regulator, verifiable in that regulator’s public register.

White-label casino — a site running on another company’s licence and platform, where the licence holder, not the brand, carries the obligations.

Sweepstakes casino — a model using virtual currencies and prize redemption to operate outside gambling licensing in some jurisdictions.

Crypto casino — a site accepting cryptocurrency as a payment method; the payment rail changes, the house edge and licence duties do not.

Mirror domain — a numbered or renamed copy of a site used where access is blocked; the licence number in the footer is what identifies a genuine one.

Affiliate site — a site that reviews or lists operators and is paid for referrals rather than by taking bets; this site is one.

Alternative dispute resolution (ADR) — an independent body that rules on complaints; some licences require one and others, including offshore frameworks, do not.

Segregation of player funds — holding customer balances separately from operating money, so they survive insolvency; required by some regulators only.

Geo-blocking — refusing access from jurisdictions a licence does not cover, usually by IP address.

Excluded territories — the countries listed on a licence where the operator may not offer its service.

Technical terms

Provably fair — a scheme, mostly on crypto sites, letting a player verify a result was not altered after the bet; it does not change the house edge.

Certification laboratory — an independent testing house that verifies a game’s random number generator and its stated return.

Seamless wallet — an integration where one balance is shared across all game providers on a site.

Latency — the delay between an action and its result on screen, which matters for live tables and crash games.

Demo (play-for-fun) mode — a version running on the same software without real stakes; the return is the same, the risk is not.

Staking and strategy terms

Bankroll — the money set aside for gambling, kept separate from funds needed for anything else.

Flat staking — keeping every stake the same size so one result cannot reshape the bankroll.

Martingale system — doubling the stake after each loss; it reaches the table limit or the end of the bankroll long before it reaches a win.

Kelly criterion — a formula sizing a stake from the perceived edge; with no edge it returns a stake of zero.

Arbitrage betting — covering every outcome at different operators for a guaranteed small profit; operators restrict accounts that do it.

Hedging — placing a second bet against the first to lock in part of a position, at the cost of the margin on both.

Expected value — the average result of a bet repeated indefinitely; negative for every game whose return to player is below 100 per cent.

If a term here contradicts the wording in an operator’s own rules, the operator’s published text governs — the definitions on this page describe standard industry usage, not any single company’s terms.