📚
Casino
9 minOnline casino glossary: the terms that actually matter
The vocabulary that decides what a game costs, what a bonus is worth, and whether you get paid. Grouped by where you meet it.
The fundamentals: the maths of gambling
| Term | What it means |
|---|---|
| RTP | Return to player. The share of all money staked that a game returns over an enormous sample. 96% means 4% is the long-run cost |
| House edge | The mirror of RTP. A 96% RTP is a 4% house edge |
| Volatility | How results are distributed. High volatility means rare large wins; low means frequent small ones. It does not change the cost |
| Hit frequency | The proportion of rounds that return anything at all, however small |
| RNG | Random number generator. The software producing outcomes in non-live games |
| Provably fair | A cryptographic system letting you verify that a result was fixed before you bet |
| Element of risk | House edge measured against total money actually risked, rather than against the initial bet. More meaningful in games where you raise |
| Variance | Used interchangeably with volatility in casino contexts |
| Expected value | The average result of a bet over the long run. Negative on every casino game |
Bonuses: the vocabulary of the conditions
| Term | What it means |
|---|---|
| Wagering requirement | The volume of bets needed before bonus money becomes withdrawable. x30 on a $100 bonus means $3,000 staked |
| Rollover | The same thing, different word |
| Sticky bonus | The bonus amount itself never becomes withdrawable — only winnings generated from it |
| Non-sticky | The bonus converts to real money once wagering is met |
| Game weighting | How much each game type counts toward wagering. Slots usually 100%, table games 10 to 20%, sometimes zero |
| Maximum bet | The stake cap while a bonus is active. Exceeding it can void the bonus and the winnings |
| Maximum cashout | A cap on what you can withdraw from bonus winnings, regardless of how much you won |
| No-deposit bonus | A bonus granted without depositing. Almost always carries a low maximum cashout |
| Free spins | Slot spins granted at a set value, usually with wagering attached to the winnings |
| Reload bonus | An offer on a subsequent deposit rather than the first |
| Cashback | A share of losses returned, sometimes as cash, more often as bonus funds with their own conditions |
The games: slots and tables
| Term | What it means |
|---|---|
| Payline | A pattern across the reels on which matching symbols pay |
| Ways to win | An alternative to paylines, where adjacent matching symbols pay regardless of position |
| Scatter | A symbol that pays or triggers a feature regardless of position on the reels |
| Wild | A symbol substituting for others to complete a win |
| Bonus buy | Paying directly to enter a feature round. Usually similar or slightly worse RTP at far higher volatility |
| Megaways | A mechanic where the number of symbols per reel varies each spin |
| Cascading reels | Winning symbols disappear and are replaced, allowing chained wins |
| Progressive | A jackpot funded by a slice of every qualifying bet |
| Basic strategy | The chart of mathematically optimal decisions in blackjack |
| Side bet | An optional additional wager at a table, almost always with a much higher house edge than the main game |
| La partage | A roulette rule returning half your even-money stake on zero, halving the edge |
| Free odds | The craps bet paid at true odds with no house margin |
| Push | A tie in which the stake is returned |
The account, the live tables and the money
| Term | What it means |
|---|---|
| KYC | Know Your Customer. The identity verification required before withdrawal |
| Source of funds | Documentation proving where deposited money came from. Requested on larger withdrawals |
| Closed loop | The rule that withdrawals return to the payment method used for the deposit |
| Pending period | The time an operator holds a withdrawal before processing it |
| Reverse withdrawal | A feature letting you cancel a pending withdrawal and return the money to your balance. Turn it off |
| Self-exclusion | A binding request to be blocked from an account for a defined period |
| Timeout | A shorter, voluntary cooling-off period |
| Deposit limit | A cap you set on your own deposits |
| Live dealer | A game streamed from a studio with a physical dealer and physical equipment |
| Game show | A live-studio format built around a wheel or presenter, usually with a far higher house edge than classic tables |
| Betting window | The timed period in which bets can be placed at a live table |
| VIP or loyalty programme | Tiered rewards based on volume wagered. The value is usually far below the amount you must lose to reach it |
| Rakeback | A share of the operator's take returned to high-volume players |
Put this guide to use
Ranked on the size of the game library, with payout reliability as the deciding criterion.
Also in this ranking: Ninecasino, 1win.
Best crypto casinos