Casino and slots
- RTP
- Return to player: the share of all bets a game pays back on average over the long run.
- House edge
- The average share of each bet the casino keeps. For a slot it's 100% minus the RTP.
- Volatility
- How unevenly wins are spread: small and often, or rare and large.
- RNG
- Random number generator, which decides the result of every spin or deal.
- Wild
- A symbol that substitutes for others to complete a winning combination.
- Scatter
- A symbol that pays in any position and usually triggers the bonus game.
- Free spins
- Free rounds, either as a casino bonus or as a feature inside a slot.
- Progressive jackpot
- A prize that grows with a slice of every bet until someone wins it.
- Bonus buy
- The option to buy straight into a slot's bonus game for a fixed price.
- Big win
- Player slang for a large slot win, often shared as a clip.
Bonuses
- Wagering requirement
- How many times you must bet a bonus before you can withdraw it.
- No-deposit bonus
- A bonus that needs no deposit, usually with high wagering and a cashout cap.
- Cashback
- Part of your net losses returned over a set period.
- Free bet
- A free stake from a bookmaker; if it wins, you usually get only the profit.
Sports betting
- Odds
- The number your stake is multiplied by if you win. It reflects the estimated probability plus margin.
- Margin
- The bookmaker's commission built into the odds.
- Single
- A bet on one outcome.
- Accumulator
- A bet on several outcomes at once with the odds multiplied; it only wins if every leg wins.
- System bet
- A set of accumulators of a given size built from your selections.
- Handicap
- A virtual head start or deficit applied to a team for settling the bet.
- Totals
- A bet on the total goals, points or games being over or under a set line.
- In-play
- Betting during the match, with odds changing constantly.
- Bankroll
- The money set aside for gambling or betting.