Glossary · 112 terms
Roulette Glossary
Every term used on this site, with the French originals where they are still spoken at the table.
American roulettevariantWheel with 0 and 00, 38 pockets, house edge 5.26%. Not the default model on this site.Announced bettableSynonym for call bet: a wheel-sector bet spoken to the dealer, who places the chips.ApronequipmentThe sloped area between the ball track and the pockets, where the deflectors sit.Ball trackequipmentThe rim groove the ball runs along before it slows and falls. Also: upper track.BankrollmoneyThe total amount set aside for play. Bankroll management is deciding how much of it to risk per bet and per session.BasketbetOn a single-zero wheel: 0, 1, 2, 3 with one chip, pays 8:1. Also: first four, quatre premiers.Biased wheellabA wheel whose physical defects make some pockets more likely than 1/37. Rare, detectable only with thousands of recorded spins.BlackbetEven-money bet on the 18 black numbers. French: noir.Call bettableA bet announced to the dealer rather than placed by hand, usually a wheel-sector bet such as voisins or tiers. Also “announced bet”.CarréFR · cornerFrench for corner: one chip on the intersection of four numbers, pays 8:1.ChevalFR · splitFrench for split: one chip on the line between two numbers, pays 17:1.Chi-square testlabStatistical test comparing observed hits per pocket with the expected n/37. Used to judge whether a wheel is biased.ColonneFR · columnFrench for column bet, pays 2:1.ColumnbetTwelve numbers in one vertical column of the layout, pays 2:1.CornerbetFour numbers sharing a corner on the layout, pays 8:1.CroupierpeopleThe dealer at a roulette table.DeflectorequipmentOne of the metal obstacles on the apron that scatter the falling ball. Also: canoe, diamond, pin.DollyequipmentThe marker placed on the winning number on the layout while bets are settled.Double zerovariantThe 00 pocket of the American wheel. Its presence raises the house edge from 2.70% to 5.26%.DouzaineFR · dozenFrench for dozen: première (1–12), moyenne (13–24), dernière (25–36).Dozenbet1–12, 13–24 or 25–36, pays 2:1.DrawdownmoneyThe fall from a bankroll peak to a later low within a session. Maximum drawdown is the largest such fall.En prisonruleFrench rule: when zero hits, an even-money bet is held for the next spin instead of lost. Halves the house edge on those bets.European roulettevariantSingle-zero wheel, 37 pockets, house edge 2.70%. The canonical model on this site.Even-money betbetRed/black, odd/even, high/low. 18 numbers, pays 1:1.Expected lossmathExpected value times total amount wagered; the average amount lost over a session or a period.Expected valuemathThe average result per bet over the long run. −1/37 of the stake for every standard European bet.FinalebetCall bet on all numbers ending in the same digit, e.g. finale 5: 5, 15, 25, 35.Flat bettingstrategyWagering the same amount every spin. The baseline every progression is compared against.French roulettevariantSingle-zero wheel with la partage or en prison, lowering the even-money house edge to 1.35%.FretequipmentThe metal divider between two pockets on the wheel.Gambler's fallacymathThe belief that past spins change the odds of the next one. They do not: spins are independent.High / LowbetEven-money bets on 19–36 (high, passe) or 1–18 (low, manque).House edgemathThe share of each stake the casino keeps on average: 2.70% in European roulette.Impair / PairFR · odd/evenFrench for odd and even.Independent spinsmathEach spin has the same probabilities regardless of history. The basis for every calculation on this site.Inside betbetAny bet placed on or between the numbers of the grid: straight up, split, street, corner, six line.Jeu zéroFR · sector“Zero game”: the seven numbers nearest zero (12, 35, 3, 26, 0, 32, 15), bet with four chips.La partageruleFrench rule: when zero hits, half of an even-money stake is returned. Halves the house edge on those bets to 1.35%.LayoutequipmentThe printed betting grid on the table. Also: table, felt, cloth.Manque / PasseFR · low/highFrench for low (1–18) and high (19–36).MartingalestrategyProgression that doubles the bet after each loss. See the Strategy section for what it does and does not do.Monte Carlo simulationlabRunning thousands of random sessions to see the distribution of outcomes. The method behind the simulators here.NeighborsbetA number and the two pockets on either side of it on the wheel, five straight-up chips.Noir / RougeFR · black/redFrench for black and red.Odd / EvenbetEven-money bets on the 18 odd or 18 even numbers. Zero is neither.OrphelinsFR · sector“Orphans”: the eight numbers left over by voisins and tiers: 17, 34, 6 and 1, 20, 14, 31, 9.Outside betbetA bet on the boxes surrounding the grid: dozens, columns and even-money bets.PayoutmoneyWhat a winning bet returns, quoted as “X to 1” on top of the returned stake.PleinFR · straight upFrench for straight up: one chip on a single number, pays 35:1.PocketequipmentOne of the 37 numbered compartments on the rotor. Also: slot, cup.ProbabilitymathChance of an outcome, from 0 to 1 or 0% to 100%. One number: 1/37 = 2.70%.ProgressionstrategyAny rule that changes the stake based on previous results. Negative progressions raise it after losses, positive after wins.Quatre premiersFR · basketFrench for the basket bet: 0, 1, 2, 3.RedbetEven-money bet on the 18 red numbers. French: rouge.Risk of ruinmathProbability of losing the whole bankroll before reaching a target or spin count.RNG roulettevariantRoulette with a software random number generator instead of a physical wheel. Same odds, no wheel bias possible.RotorequipmentThe spinning part of the wheel that carries the pockets.SectorwheelA contiguous arc of pockets on the wheel, as distinct from a group on the layout.Six linebetSix numbers in two adjacent rows, pays 5:1. French: sixain.SixainFR · six lineFrench for six line: six numbers in two rows, pays 5:1.SplitbetTwo adjacent numbers, pays 17:1.Standard deviationmathSquare root of variance; the typical distance of a result from the expected value.Straight upbetA single number, pays 35:1.StreetbetThree numbers in a row of the layout, pays 11:1. French: transversale.Table limittableMinimum and maximum bet allowed. The maximum is what stops doubling progressions.Tiers du cylindreFR · sector“Third of the wheel”: the twelve numbers opposite zero, 27 to 33 on the wheel, bet with six splits.TransversaleFR · streetFrench for street (transversale pleine, 3 numbers) and six line (transversale simple, 6 numbers).VariancemathA measure of how widely results spread around the expected value. High for straight up, low for even-money bets.Voisins du zéroFR · sector“Neighbors of zero”: the seventeen numbers from 22 to 25 on the wheel, bet with nine chips.Wheel headequipmentSynonym for rotor: the spinning part carrying the numbers.ZerowheelThe single green pocket that no even-money, dozen or column bet covers; the source of the house edge. Also: single zero, 0.BallequipmentThe small ball launched along the track against the rotor. Modern balls are ivorine or Teflon, 18–21 mm.Betting windowliveThe period in a live round during which bets are accepted, timed by the game server and shown as a countdown.Buy-intableExchanging cash for chips at the table. Done between spins, with the cash placed on the layout rather than handed to the dealer.ChipmoneyA token representing a fixed amount, placed on the layout to make a bet. Also: check.Cold numbermythA number that has not appeared for many spins. Carries no information about future spins on a fair wheel.Color chipstableRoulette-only chips in a color unique to each player at the table, with a value set at buy-in. Also: wheel checks.Complete betbetAll inside bets that include a given number: the straight up, every split, street, corner and six line it belongs to. Also: complet; at the table limit, a maximum.D'AlembertstrategyProgression that adds one unit after a loss and removes one after a win.Degrees of freedomlabThe number of independent values in a statistic. For a chi-square test on 37 pockets it is 36, because the counts must add up to the total.Faites vos jeuxFR · procedure“Place your bets.” The dealer’s call that opens betting for a round.FibonaccistrategyProgression that follows the sequence 1, 1, 2, 3, 5, 8, 13…: one step forward after a loss, two steps back after a win.HoldmoneyThe share of the money players bring to the table that the casino actually keeps. Higher than the house edge because winnings are re-bet.Hot numbermythA number that has appeared more often than expected recently. On a fair wheel it predicts nothing.LabouchèrestrategyCancellation system: write a line of numbers, bet the sum of the two ends, cross them off after a win, add the lost stake after a loss.Law of large numbersmathThe average of independent results converges to the expected value as the number of trials grows.No more betsprocedureThe dealer’s call (or the on-screen prompt) that closes betting. Chips may no longer be placed, moved or removed.p-valuelabThe probability of seeing a deviation at least as large as the one observed if the wheel were fair.ParolistrategyPositive progression: double after a win, reset after a loss or after three wins in a row. Also: reverse Martingale.RacetracktableThe oval strip on live and electronic layouts showing the numbers in wheel order, used to place neighbors and sector bets in one tap.Rien ne va plusFR · procedure“Nothing goes any more.” The French call for no more bets.RTPmoneyReturn to player: the share of wagers paid back on average. European roulette: 97.30%, which is 100% minus the 2.70% house edge.Snake betbetTwelve red numbers that zigzag down the layout: 1, 5, 9, 12, 14, 16, 19, 23, 27, 30, 32, 34. Pays 2:1 like a dozen where offered.Stop-lossstrategyA pre-set amount of loss at which you end the session.Stop-winstrategyA pre-set profit target at which you end the session.TurnovermoneyThe total amount wagered over a session or period, counting re-bet winnings. Also: handle, action.UnitmoneyThe base stake a system or a player works in. Progressions are described in units so they apply at any table.Visual ballisticslabPredicting the drop sector by eye, from the ball’s and rotor’s speeds, without a device.BowlequipmentThe fixed outer part of the wheel: the wooden or composite rim that holds the ball track and apron, inside which the rotor spins.Side betbetAn optional extra wager attached to the main game, usually on a streak, a bonus event or a jackpot. Almost always dearer than the standard bets.Progressive jackpotmoneyA top prize that grows by a slice of every bet until someone wins it, then drops back to a starting amount, the seed.Break-evenmathThe point where a bet’s expected value is exactly zero, so neither side has an edge. Usually a payout or a jackpot size.True oddsmathThe payout that would make a bet fair: losing outcomes divided by winning ones. A straight up on 37 pockets has true odds of 36 to 1.Pay tablemoneyThe list of what each bet or result pays. On machines and side bets, it is where the house edge is set.Fair gamemathA game in which neither side has an edge: every bet has an expected value of zero.Birthday problemmathHow many people it takes before two probably share a birthday, or how many spins before a number probably repeats. On a 37-pocket wheel, 8 spins are enough for a better-than-even chance.AntemoneyA fixed amount paid to take part in a round, before anything is decided. It is gone whatever happens.Wild cardruleA card, usually a joker, that counts as whatever card makes the best hand.Prime numbermathA whole number above 1 that only 1 and itself divide exactly: 2, 3, 5, 7, 11, 13 and so on.Hot handmythThe belief that a run of wins, or of one result, makes another more likely. At the wheel it is the gambler’s fallacy turned around.Inverse gambler's fallacymathConcluding from one unusual result that many tries must have come before it.