Gambling glossary

Casino vocabulary is mostly plain once someone explains it, and it is rarely explained. This glossary covers the terms that carry real money consequences rather than the ones that just sound technical.

Where an entry quotes a figure, it comes from the computed sections of this site and links to the page where it is derived. A definition and its arithmetic should not live in different places.

Odds & money

• Bankroll — The money set aside for gambling, kept separate from money needed for anything else.
• Expected value — The average result of a bet if it could be repeated indefinitely.
• Flat betting — Wagering the same amount every hand regardless of what came before.
• House edge — The average share of each bet the casino expects to keep over the long run.
• Martingale — Doubling after every loss until a win recovers everything, plus one unit.
• RTP — Return to player: the mirror of house edge, quoted as what comes back rather than what is kept.
• Standard deviation — A measure of how far results typically stray from the average.
• True odds — The payout that would make a bet exactly fair, with no advantage to either side.
• Unit — One standard bet, used as the yardstick for measuring results and bankroll.
• Variance — How widely results scatter around their expected value.
• Vigorish — The built-in charge a house takes, whether as a commission, a shaded payout, or a rake.

Casino floor

• Cage — The secure counter where chips are exchanged for money.
• Chip — The casino's own token, standing in for money at the table.
• Colour up — Exchanging a pile of small chips for fewer larger ones before leaving the table.
• Commission — A percentage charged on winning bets that would otherwise favour the player.
• Comp — Complimentary goods or services given to players based on tracked play.
• Cut card — A coloured plastic card placed in the shoe to mark where dealing stops.
• Drop — The total money exchanged for chips at a table, measured by the drop box.
• Eye in the sky — The casino's surveillance system, and the department that runs it.
• Handle — The total amount wagered, counting every bet including money won and re-bet.
• High roller — A player whose stakes justify individual attention from the casino.
• Hold — The share of buy-ins a casino keeps, which is not the same as the house edge.
• Marker — A line of credit extended by the casino, drawn at the table.
• Natural — A hand that wins immediately on the first cards dealt.
• Penetration — The proportion of a shoe dealt before the reshuffle.
• Pit boss — The supervisor responsible for a group of tables.
• Push — A tie in which the bet neither wins nor loses and the stake is returned.
• Rating — The casino's record of your average bet and time played.
• Shoe — The box holding several shuffled decks from which cards are dealt.
• Table etiquette — The unwritten rules of behaviour at a casino table.
• Theoretical loss — What the casino expects to win from a player, used to set comps and credit.
• Toke — A tip to a dealer, often made as a bet placed on their behalf.

Poker

• Ante — A small forced bet from every player, used alongside or instead of blinds.
• Blind — A forced bet posted before the cards are dealt.
• Button — The dealer position, which acts last on every postflop street.
• Combinatorics — Counting the exact number of card combinations that make up a range.
• Cutoff — The seat immediately to the right of the button.
• Equity — Your share of the pot, meaning how often you win it if the hand plays to showdown.
• Fold equity — The value that comes from an opponent folding, separate from winning at showdown.
• Implied odds — The money you expect to win later if your draw comes in, beyond what is in the pot now.
• Outs — The cards remaining that would improve your hand to a likely winner.
• Position — Where you act in the betting order, and the largest structural edge in poker.
• Pot odds — The price a call is getting, compared against how often it needs to win.
• Rake — The house's cut of each pot, or the fee on a tournament entry.
• Range — The full set of hands a player could hold, rather than a guess at one specific hand.
• Straddle — A voluntary blind raise posted before the cards, usually double the big blind.
• Tilt — Playing worse than you can because of emotion rather than judgement.
• Under the gun — The seat immediately left of the big blind, first to act before the flop.

Tournaments

• Bubble — The point at which the next player eliminated finishes just outside the money.
• Chop — An agreement among remaining players to split the prize pool rather than play it out.
• Freeroll — A tournament with no entry fee, or a situation where you cannot lose but might win.
• Guarantee — A minimum prize pool the organiser commits to regardless of entries.
• ICM — Independent Chip Model: the conversion from tournament chips into real money value.
• Overlay — The shortfall an organiser covers when entries do not reach the guarantee.

The four worth reading first

House edge is the number every other page on this site is about, and the one casinos never print.

Hold explains why a 1.4% edge produces a 15% loss over a visit, which is the gap most players never account for.

True odds is the comparison that prices any bet in seconds, and shows that a 180:1 payout can be worse value than an even-money one.

Variance is why a night's results tell you nothing about whether a bet was good.

Where an entry quotes a number, that figure comes from the computed sections of this site rather than from another glossary, so the definition and the derivation cannot drift apart. Each entry links to the page where the number is worked out.