Short definitions of the terms the calculators use, grouped by where you meet them. Each links to the guide that explains it in full.
Bonus terms
Bonus funds. Money a casino credits to your account as part of a promotion. It cannot be withdrawn until the playthrough is met, and regulators call it restricted credit for that reason. See what a playthrough requirement means.
Bonus spins. Spins a casino gives you on a named slot without charging the bet. What you win with them may come with its own playthrough, which you can check with the wagering requirement calculator by entering the winnings as the bonus.
Deposit match. A bonus worth a percentage of your deposit, for example 100% up to a set amount. A $100 deposit with a 100% match adds $100 of bonus funds.
Eligible games. The games whose bets count toward a playthrough. Licensed casinos in New Jersey, Pennsylvania and Michigan must list them in the terms. See game contribution.
Expiry. The deadline for meeting a playthrough. An unfinished requirement usually means the bonus is forfeited. See the bonus rules the calculator cannot see.
Game contribution. The share of each bet that counts toward a playthrough. At 20%, a $1 bet clears 20 cents. See game contribution.
Maximum bet rule. A cap on the stake per spin or hand while a bonus is active, found in some bonus terms. Breaking it can void the bonus and its winnings.
No-deposit bonus. A bonus credited without a deposit. Because none of your money is at risk, the worst outcome is ending with nothing. See what a bonus is worth.
Order of funds. The order a casino uses your deposit, bonus funds and bonus winnings in while a bonus is active. Regulated terms must state it.
Playthrough requirement. The total amount you must bet before bonus funds become withdrawable, written as a multiple such as 15x. Also called a wagering, rollover or turnover requirement. See what a playthrough requirement means.
Winnings cap. A limit on how much of a bonus win can be withdrawn. Licensed casinos in New Jersey, Pennsylvania and Michigan may not cap winnings once you have met a promotion’s terms. See how regulated US casino bonuses are structured.
Game math
Expected value. The average result of a bet or a bonus across a very large number of tries. For a slot spin it is the bet times (RTP minus 1), a negative number below 100% RTP.
Hit frequency. The share of spins that pay anything, including payouts smaller than the bet. See hit frequency.
House edge. The share of every bet a game keeps on average: 100% minus the RTP. A 96% slot has a 4% edge. See what RTP means.
Maximum win. The largest payout a game can make, usually shown as a multiple of the bet. A very high maximum win is a sign of high volatility.
Paytable. The game’s list of winning combinations and what each pays. It shows payouts, not how often each lands.
Progressive jackpot. A prize that grows as players bet, until someone wins it. In Michigan, the projected contribution of a progressive jackpot may not be counted toward a game meeting the state’s minimum RTP.
Random number generator (RNG). The software that decides each spin. The test standard for online games requires its results to be independent of previous games. See why RTP only shows up over many spins.
RTP (return to player). The share of all money bet that a game is designed to pay back over its full cycle of outcomes. One title can be offered at several RTP settings. See what RTP means.
Standard deviation. The typical distance between one result and the average. For a slot it is measured per spin, in bets, and it is the usual way to put a number on volatility.
Volatility. How a game spreads its return: many small wins (low volatility) or a few large ones (high volatility). It does not change the RTP. See slot volatility explained.
Session terms
Bankroll. The money you set aside for a session and are prepared to lose. Measure it in bets: $200 at $1 a spin is 200 bets. See choosing a bet size.
Deposit limit. A cap you set on how much you can pay into your casino account per day, week or month. Licensed casinos in New Jersey and Pennsylvania must offer one. See session limits.
Self-exclusion. A formal program, run by a state regulator, that bars you from gambling for a set period. See the responsible gambling page.
Spend limit. A cap on how much of your deposited money you can put at risk in a period.
Spins per minute. Your pace. It multiplies the hourly cost of a session. See spin speed.
Theoretical loss. The expected loss on a session: total bet times house edge. At $1 a spin, 600 spins an hour and a 4% edge it is $24 an hour. See expected loss per hour.
Time limit. A cap you set on daily playing time. When it runs out at a licensed New Jersey or Pennsylvania casino, you can finish the round you are in.
Turnover. The total amount bet, counting wins you bet again. A $200 bankroll at 96% RTP turns over $5,000 on average before it is gone. See the session and bankroll calculator.
Common questions
What is the difference between RTP and house edge?
They are two sides of the same number. RTP is the share of money bet that a game pays back over the long run, and the house edge is the share it keeps. They always add up to 100%, so a 96% RTP slot has a 4% house edge.
What does turnover mean at a casino?
Turnover is the total amount you have bet, counting every bet including wins you bet again. Wagering requirements are measured in turnover, which is why $1,500 of playthrough costs far less than $1,500 on average.