Online Casino Glossary: Casino Terms Explained

This glossary explains the terms you will meet in casino terms and conditions, bonus pages and licence statements, in plain language and with examples. It describes how these things usually work at online casinos in general. The exact rules at any particular casino are in that operator's own terms.

Odds and Game Maths

Bankroll — The money you have set aside for gambling, kept separate from money for bills and savings. Budgets, bet sizes and stop-losses are all worked out from it.

House edge — The share of each bet a game keeps on average over the long run. European roulette has a 2.70% edge: over a large number of bets, $100 staked returns $97.30 on average.

Return to Player (RTP) — The share of all bets a game pays back over a very large number of rounds; 100% minus RTP is the house edge. A 96% RTP slot keeps 4% on average. The same slot can be released at several RTP settings, so check the figure in the game's information panel.

Volatility — How unevenly a game pays out. High-volatility slots pay rarely but in larger amounts, while low-volatility slots pay small amounts often. Volatility does not change the house edge, but it does change how quickly a budget can run out.

Turnover — The total of all bets placed, including winnings bet again. Expected loss is turnover times house edge, which is why 500 spins at $1 count as $500 of turnover even if the deposit was $100.

Expected loss — The average amount a player loses over a given turnover: turnover multiplied by the house edge. Any single session can end well above or below it.

Random Number Generator (RNG) — The software that decides the outcome of digital games. Each result is independent of the previous one. Licensed operators must use RNGs tested by an approved laboratory.

Gambler's fallacy — The mistaken belief that past results change future odds in independent games, for example that black is "due" after five reds. The odds on the next spin stay the same.

Bonuses and Promotions

Welcome bonus — An offer for new accounts, usually a percentage match on the first deposit, sometimes with free spins. It nearly always comes with wagering requirements.

Wagering requirement — How many times a sum must be bet before bonus money can be withdrawn. A $100 bonus at 35x requires $3,500 of bets. If the multiplier applies to deposit plus bonus, the figure doubles.

Game weighting — How much each game counts towards wagering. Slots usually count 100%, table games 10% or less, and live dealer games often 0%.

Maximum bet rule — The highest stake allowed while a bonus is active, often around $5 per spin. Breaking it can void the bonus and any winnings made with it.

Free spins — Slot rounds paid for by the casino at a fixed stake. Winnings are usually credited as bonus money with their own wagering requirement and sometimes a cap on how much can be withdrawn.

No deposit bonus — A small bonus or a number of free spins credited without a deposit. These usually have high wagering and a low maximum cashout, so treat them as a free trial, not a source of money.

Bonus code — A word or string entered at registration or in the cashier to claim an offer. A code is only real if the operator publishes it on its own promotions page and the cashier accepts it.

Sticky bonus — A bonus that can be played with but never withdrawn; it is removed when you cash out. A non-sticky bonus is used only after your own deposit runs out, so you can withdraw winnings made from the deposit before touching the bonus.

Cashback — A percentage of net losses returned over a period, sometimes as cash and sometimes as bonus money with wagering. Ten percent cashback on a $200 net loss is $20.

Reload bonus — A deposit match for existing players, usually smaller than the welcome bonus and with the same kind of wagering conditions.

Maximum cashout — The most that can be withdrawn from winnings made with a bonus or free spins. Any amount above the cap is removed when you withdraw.

Payments and Accounts

KYC (Know Your Customer) — Identity checks a licensed operator must carry out, usually photo ID, proof of address and proof of payment method. Doing them before the first withdrawal avoids delays later.

Pending period — The time a withdrawal request waits before the operator processes it. During this time some casinos let players cancel the request and play the money again, so a long pending period works against the player.

Withdrawal limit — The most an operator will pay out per day, week or month. It is set in the terms, and large wins may be paid in instalments.

Closed loop — The rule that withdrawals go back to the payment method used for the deposit, where that method allows it. It is part of anti-money-laundering controls.

E-wallet — An online payment account such as Skrill or Neteller that sits between your bank and the casino. Some bonuses exclude deposits made with certain e-wallets, and the bonus terms say which.

Licences and Player Protection

Gaming licence — Permission from a regulator to offer gambling, issued to a named company for named domains. You can confirm it only in the regulator's own register, not through a seal image on the casino's page.

Licence register — The regulator's public list of licence holders, showing the company, licence number, status, dates and usually the domains covered. Search it by domain and company name, not by brand.

B2C and B2B licence — A B2C licence allows a company to run a casino for players. A B2B licence covers suppliers such as game studios and platforms that serve other operators. A casino that shows a B2B number as its own licence is not showing its own licence.

Licence seal — A badge in a casino footer that should link to the regulator's own website and show the licence entry. A seal that does not link anywhere, or links to the casino's own domain, proves nothing.

ADR (Alternative Dispute Resolution) — An independent service that decides complaints the operator has not resolved. Under Anjouan rules a complaint goes to the operator first. After 30 days it can go to an approved ADR provider, and the operator pays for it.

Restricted countries — The countries whose residents an operator does not accept, listed in its terms. Accounts opened from those countries can be closed and winnings withheld.

Self-exclusion — A request to be blocked from gambling for a set period, either with one operator or through a national scheme. A licensed operator must honour it for the whole period.

Deposit limit — A cap you set on how much you can deposit per day, week or month. Lowering a limit takes effect at once, while raising it usually needs a waiting period.

Reality check — A pop-up reminder of how long you have been playing and how much you have won or lost, shown at intervals you choose.

Game Terms

Payline — A line across the reels on which matching symbols pay. "Ways to win" slots pay matching symbols on adjacent reels from left to right instead of on fixed lines.

Wild symbol — A slot symbol that substitutes for others to complete a winning combination. Some wilds also expand, stick in place or carry multipliers.

Scatter symbol — A slot symbol that pays or triggers a feature wherever it lands, regardless of paylines. Three or more usually start free spins.

Progressive jackpot — A prize that grows with a small share of every bet until someone wins it. Part of the RTP goes into the jackpot, so the base game usually returns less.

Bonus buy — A feature that lets you pay a fixed price, often 100 times the stake, to start a slot's bonus round directly. The game's information panel shows its price and RTP.

Basic strategy — The mathematically best play for every blackjack hand against every dealer upcard. It brings the house edge down to about 0.5% under common rules.