Casino Glossary: Key Terms Explained

A plain-English guide to the words you will meet at online casinos worldwide.

Online casinos come with their own vocabulary, and the same term can mean very different things for your money. This global glossary explains the words you will meet most often — from RTP and volatility to wagering, KYC and sticky bonuses — in plain English. Availability and legality differ by country, so always check the per-country guide for your market before you play.

Why a casino glossary matters

Every online casino is built on a small set of recurring concepts, and most misunderstandings come from not knowing what a single word actually means. A bonus that looks generous can be tied up by a wagering requirement, a slot that looks lively can be high in volatility, and a withdrawal can be paused simply because an identity check has not been completed. None of these are tricks; they are standard mechanics with standard names. Once you understand the vocabulary, you can read a promotion or a game’s information panel and judge it for yourself rather than relying on the headline.

This guide is a global reference. It explains the terms in a way that applies anywhere, but it does not tell you which casinos you may legally use, because that depends entirely on where you live. The games themselves are typically built by licensed studios, yet the casino that offers them must also hold a licence valid in your own country. For the rules, licensing and recommended operators in your market, use the menu to open your national guide, or browse our Guides hub.

RTP, house edge and volatility

RTP stands for Return to Player. It is the percentage of all wagered money that a game is designed to pay back to players over a very large number of rounds. An RTP figure is a long-run theoretical average, not a promise about your individual session — over a short visit you can win far more or lose far more than the percentage suggests. The mirror image of RTP is the house edge, the casino’s built-in mathematical advantage. If a game returns most of the stake to players on average, the remainder is the house edge, and it is how the casino covers its costs and makes a profit over time.

Volatility (sometimes called variance) describes how a game’s wins are distributed. A low-volatility slot tends to pay smaller amounts frequently, which keeps a balance ticking along; a high-volatility slot pays rarely but can deliver much larger wins when it does. Two games can share the same RTP yet feel completely different to play because of volatility. Knowing this helps you match a game to your budget and your patience: high-volatility titles can drain a small bankroll quickly between wins, while low-volatility titles stretch play but rarely produce dramatic results.

RNG and game fairness

An RNG, or Random Number Generator, is the software that decides the outcome of each spin, card or roll. A properly implemented RNG produces results that are statistically independent, meaning a previous outcome has no influence on the next one — there is no “due” win and no pattern to exploit. Reputable game studios have their RNGs tested by independent laboratories, and licensed casinos are generally required to use games that meet these testing standards.

In live-dealer games the randomness comes from real cards, wheels and dice streamed in real time, but the studio running the table is still a licensed, audited operation. Fairness, then, is not something you can verify by watching a single session; it rests on certification and on the casino holding a valid licence. This is why playing only at operators licensed for your country matters: that licence is what ties the game’s tested fairness to enforceable consumer protection where you live.

Bonuses, wagering and free spins

A bonus is extra value a casino credits to your account, most commonly a deposit match (a percentage added on top of what you put in) or free spins on selected slots. The single most important term attached to almost any bonus is the wagering requirement, also written as a playthrough or rollover. It is a multiplier stating how many times you must bet the bonus — and sometimes the deposit too — before any winnings can be withdrawn. A higher multiplier means more turnover is required, so a “bigger” bonus is not automatically a better one.

Two further details shape how a bonus behaves. Game weighting determines how much each bet counts toward the requirement; slots often count fully while table games count partially or not at all. Maximum bet limits and time limits restrict how you can clear the requirement and how long you have to do it. Free spins usually generate winnings that are themselves subject to wagering. Reading these conditions before you opt in is the difference between a bonus that adds genuine value and one that simply locks up your money.

Sticky vs. cashable bonuses

Bonuses fall into two broad families, and the distinction matters at withdrawal time. A cashable (or non-sticky) bonus lets you keep the bonus funds once wagering is met — the bonus amount becomes part of your withdrawable balance. A sticky bonus is different: the bonus itself can never be withdrawn. You play with it, and only the net winnings produced on top of it can be cashed out, while the original bonus amount is removed when you withdraw.

Neither type is inherently good or bad, but they suit different goals. A sticky bonus gives you more funds to play with and absorb variance, which can be useful on higher-volatility games, but you should never treat the sticky portion as your own money. A cashable bonus is more straightforward if your aim is to keep what you earn. Always check the terms to see which kind you are accepting, because the label is not always shown prominently on the offer banner.

KYC, e-wallets and payouts

KYC stands for Know Your Customer. It is the verification process — confirming your identity, age and sometimes your address or payment method — that licensed casinos are legally required to carry out. KYC protects against fraud, money laundering and underage play, and it is normal for it to be triggered before a first withdrawal. Completing it promptly, with clear documents, is the simplest way to avoid payout delays. A request for documents is routine, not a sign that anything is wrong.

An e-wallet is a digital payment service that sits between your bank and the casino, letting you move funds without sharing card details directly each time. E-wallets are popular because they are often fast for both deposits and withdrawals, though some bonuses exclude certain payment methods, so check the terms. When a withdrawal is approved it may still pass through a pending or processing period before reaching you. Importantly, the deposit and withdrawal methods that are available, and any associated rules, vary by operator and by country — never assume a method works the same way everywhere.

Jackpots and game types

A jackpot is a top prize. A fixed jackpot pays a set amount, while a progressive jackpot grows as a small slice of many players’ bets is added to a shared pool, sometimes across multiple casinos, until someone wins it and the pool resets. Progressive prizes can become very large, but the odds of hitting them are correspondingly long, and they typically require playing under specific conditions, so the game’s rules are worth reading first.

You will also meet broad categories: slots (reel-based games driven by an RNG), table games such as blackjack and roulette, and live casino, where a human dealer hosts a real table streamed to you in real time. A paytable lists what each combination pays, and a bankroll is simply the money you have set aside to play with. Treating your bankroll as a fixed entertainment budget — not a sum you expect to grow — is the single healthiest habit a glossary like this can encourage.

Availability and legality vary by country

This glossary is intentionally global, because the terms above mean the same thing everywhere. What is not global is which casinos you may legally use and which games, payment methods and bonuses are permitted. Licensing is granted at the national level, so an operator licensed in one country is not automatically allowed to serve players in another. A live table may be run by a licensed studio, yet the casino offering it must hold a licence valid in your own country for your play to be protected.

Because of this, we do not name a single regulator here or imply any licence that an operator does not hold. For the rules, the responsible regulator, age requirements and the operators that are appropriate for your market, open the per-country guide via the menu or the Guides hub. Treat every term in this glossary as a starting point, then confirm the specifics against your national guide before you deposit.

Responsible gambling

Gambling is entertainment, not a way to make money, and the mathematics described above — the house edge in particular — means the casino holds a long-run advantage. Play only with money you can afford to lose, set deposit and time limits before you start, and never chase losses. The minimum age is 18 in most markets and higher in some, so always follow the legal age where you live. If gambling stops feeling fun, take a break and use the tools your casino and your country provide. You can read more on our responsible gambling page, and each national guide links the help resources available in that country.

FAQ

Does a high RTP mean I will win?

No. RTP is a long-run theoretical average measured over enormous numbers of rounds. In any single session you can win much more or lose much more than the percentage suggests, and the house edge still gives the casino an advantage over time.

What is the difference between a sticky and a cashable bonus?

A cashable bonus can be withdrawn once you meet the wagering requirement. A sticky bonus cannot — you play with it, but only the winnings generated on top of it can be cashed out, while the bonus amount itself is removed at withdrawal.

Why does the casino ask for my documents (KYC)?

KYC verification confirms your identity and age and is a legal requirement for licensed casinos. It commonly happens before a first withdrawal and helps prevent fraud and underage play. Submitting clear documents early is the easiest way to avoid payout delays.

What does the wagering requirement actually mean?

It is a multiplier showing how many times you must bet the bonus (and sometimes the deposit) before winnings can be withdrawn. Game weighting, maximum-bet rules and time limits all affect how quickly you can meet it, so read the full terms.

Are these terms the same in every country?

The definitions are global and do not change, but which casinos, games, payment methods and bonuses are legally available does change by country. Check your national guide via the menu or our Guides hub before you play.