Why You Need to Know the Lingo

Online casinos come with their own vocabulary. Bonus terms, game rules, and platform features are all described using specific language — and misunderstanding even one term can lead to confusion or poor decisions. This glossary covers the most important terms for anyone new to online gambling.

General Casino Terms

House Edge
The mathematical advantage the casino holds over players in any given game. Expressed as a percentage of each bet the casino expects to retain over the long run.
RTP (Return to Player)
The inverse of the house edge. An RTP of 96% means that, over millions of spins or hands, the game returns 96% of all money wagered to players. Higher RTP = better odds for players.
Variance / Volatility
How frequently and how much a game pays out. Low variance = frequent small wins. High variance = infrequent but potentially large wins.
RNG (Random Number Generator)
The software that ensures game outcomes are entirely random and not influenced by previous results. Reputable casinos use independently audited RNGs.
Bankroll
The total amount of money you have set aside for gambling.
Wagering Requirement
The number of times you must bet a bonus amount before you can withdraw any winnings from it. E.g., a £20 bonus with a 30x wagering requirement means you must wager £600 before withdrawing.

Bonus and Promotion Terms

Welcome Bonus
An offer given to new players upon registering and/or making their first deposit. Often a deposit match (e.g., 100% up to £100).
Free Spins
Bonus spins on slot games given without requiring a bet from your own funds. Winnings from free spins often carry wagering requirements.
No-Deposit Bonus
A small bonus awarded just for registering, with no deposit required. Almost always comes with significant wagering requirements.
Sticky Bonus
A bonus that cannot be withdrawn — only the winnings made from it can be cashed out.
Cashback
A promotion returning a percentage of your net losses over a defined period, sometimes as real cash and sometimes as bonus funds.

Game-Specific Terms

Payline
In slot games, a line across the reels on which matching symbols must land to form a win.
Wild Symbol
A slot symbol that substitutes for most other symbols to help complete winning combinations.
Scatter Symbol
A slot symbol that triggers bonuses or free spins, often regardless of its position on the reels.
Progressive Jackpot
A jackpot that grows over time as a small portion of every bet is added to it, across one or many linked games.
Bust
In blackjack, when a hand's total exceeds 21, resulting in an automatic loss.
Ante
A mandatory initial bet placed before cards are dealt in poker and some other table games.
Inside Bet / Outside Bet
In roulette: inside bets are placed on specific numbers or small groups (higher risk, higher reward); outside bets cover larger groups like red/black or odd/even (lower risk).

Account and Platform Terms

KYC (Know Your Customer)
Identity verification process requiring you to submit documents (ID, proof of address) before withdrawing funds.
Self-Exclusion
A responsible gambling tool allowing you to block yourself from a casino for a set period or permanently.
Withdrawal Pending Period
A time window after requesting a withdrawal during which you can reverse it. Can be used to encourage players to keep gambling — be aware of it.
Verified Account
An account that has passed KYC checks and is fully enabled for deposits, withdrawals, and bonuses.
Live Casino
Games broadcast in real-time from a studio or land-based casino, featuring real human dealers interacted with via video stream.

Quick Reference Summary

TermIn Simple Terms
House EdgeCasino's built-in mathematical advantage
RTP% of bets returned to players over time
Wagering RequirementHow many times you must bet a bonus before withdrawing
VarianceHow often and how big a game pays out
RNGSoftware ensuring random, fair outcomes

Bookmark this page and refer back to it whenever you encounter an unfamiliar term. Understanding the language of online casinos puts you in a much stronger position as a player.