03 Glossary
Glossary
The terms used in gambling, in alphabetical order.
A
- Accumulator (parlay)
A bet that links several selections on one slip and wins only if every selection wins; their odds are multiplied together. The margins of the individual selections compound along with the odds, so the bookmaker's edge on an accumulator is larger than on each selection taken on its own.
- All-in
The situation in which a poker player puts all the chips they have left at the table into play. That player can win from each opponent at most as much as they put in themselves; bets above that amount form a separate pot.
- American odds (moneyline)
The odds format used in the United States, written with a plus or minus sign. Positive odds, for example +150, show the net win on a stake of 100, and negative odds, for example −200, show how much must be staked for a net win of 100.
- Ante
A small compulsory bet placed by every player at the table before the cards are dealt, in some forms of poker and in the later stages of many tournaments. Unlike the blind, the ante is paid by every player, not only by two. In some casino games played against the house, “ante” is the compulsory opening stake.
B
- Backgammon (triple win)
Besides being the name of the game, a scoring term for a win in which the loser has not borne off any checker and still has a checker on the bar or in the winner's home board. It counts triple a single win; some local rules do not apply it and count it as a gammon.
- Banker
One of the two hands dealt in punto banco, and the bet on it winning. The banker hand wins slightly more often than the player hand (45.86% against 44.62%), so winning banker bets are paid 1 to 1 less a commission. With the usual commission, the house edge on this bet is 1.06%.
- Bankroll
The total amount a player sets aside for gambling over a period or a session, kept apart from money for other expenses. The term comes up in connection with variance: the larger the stakes relative to the bankroll, the more likely short-term swings are to exhaust it. How a bankroll is managed does not change the house edge.
- Bar
The divider in the middle of the backgammon board, on which hit checkers are placed. A player with a checker on the bar must bring it back into the opponent's home board before making any other move, which is impossible when the points shown by the dice are each held by at least two opposing checkers.
- Basic strategy
The table of decisions (hit, stand, double, split) that gives, for every combination of the blackjack player's hand and the dealer's face-up card, the decision with the smallest average loss, worked out mathematically. Basic strategy does not remove the house edge, it only reduces it: under the rules used in this site's calculations the house edge is 0.57%, against 5.67% for a player who copies the dealer's rules. The exact table depends on the table rules (number of decks, S17 or H17, doubling after a split).
- Bearing off
The final stage of a backgammon game, in which a player removes checkers from the board once all of them have been brought into their home board. The first player to bear off all 15 checkers wins.
- Blackjack (natural)
In blackjack, a two-card starting hand made of an ace and a ten-value card (10, jack, queen or king), totalling 21. It beats any other 21 and usually pays 3 to 2, a win of 1.50 times the stake; some tables pay less, which increases the house edge. The chance of being dealt a blackjack is about 4.73%.
- Blacklist (ONJN)
The list published by ONJN of gambling websites operating without a Romanian licence. This site does not reproduce the list.
- Blind
A compulsory bet placed before the cards are dealt in poker games with blinds, such as Texas hold'em and Omaha, by the two players to the left of the dealer position: the “small blind”, the smaller one, and the “big blind”, usually twice as large. The blinds make every hand start with a pot, and they move around the table from one hand to the next.
- Blot
In backgammon, a single checker alone on a point, which can be hit by an opposing checker landing there. The hit checker is placed on the bar and must re-enter the game before any other move. The chance of being hit depends on the distance from the opposing checker: with nothing blocking the way, it is 47.22% at a distance of 6 and 8.33% at a distance of 12.
- Bust
In blackjack, going over a total of 21, which loses the hand at once. A player who busts loses even if the dealer busts later; much of the house edge comes from this order of play. Under the rules used in this site's calculations, the dealer busts in about 28.16% of hands, most often with a 6 showing (42.32%) and least often with an ace (16.65%).
C
- Call
A poker player's decision to put into the pot the amount needed to match the largest bet in the current betting round.
- Cash game
A form of poker in which the chips on the table stand directly for money, players can join and leave at any time, and the blinds stay the same. The house usually takes a rake from each pot or a fee for time at the table.
- Check
A poker player's decision to put nothing into the pot and pass the turn to the next player, possible only if nobody has bet yet in the current round.
- Class II licence
The licence granted by ONJN to suppliers of services to gambling organisers, such as providers of gaming software, hosting or payment services.
- Class I licence
The licence granted by ONJN to organise gambling in Romania. Companies holding one are licensed operators.
- Column
A roulette bet on one of the three columns of the layout, each with 12 numbers (for example 1, 4, 7 and so on up to 34); it pays 2 to 1. The probabilities are the same as for a dozen: 32.43% on a European wheel; zero makes the bet lose.
- Combination
In mathematics and in lotteries, a selection of items in which order does not matter. A 6-from-49 lottery has 13,983,816 possible combinations and a 5-from-40 lottery 658,008, so a ticket with a single combination has a chance of 1 in 13,983,816 or 1 in 658,008, respectively, of matching all the numbers.
- Come bet
A craps bet that works like the pass line but is placed after a point has been set: the next roll acts as that bet's own come-out roll. It has the same house edge as the pass line, 1.41%.
- Come-out roll
The first roll of a round of craps, made when no point has been set. A 7 or 11 wins for the pass line, a 2, 3 or 12 (crap) loses, and any other total (4, 5, 6, 8, 9 or 10) becomes the point.
- Commission (baccarat)
The amount the house keeps from winning banker bets in punto banco, a small fixed share of the win. The commission makes up for the banker hand winning more often than the player hand; its size can differ, and “no commission” versions instead pay less when the banker wins with certain totals.
- Community cards
The cards turned face up in the middle of the table in community-card poker, which all players can use to make their hand. In Texas hold'em and Omaha there are five, turned in three stages: the flop, the turn and the river.
- Corner (carré)
A roulette bet on four numbers that form a square on the layout (for example 1, 2, 4 and 5), with the chip placed where they meet; it pays 8 to 1. The chance of winning is 10.81% on a European wheel and 10.53% on an American one.
- Crap
In craps, a roll totalling 2, 3 or 12. On the come-out roll, a crap makes the pass line bet lose; the “any craps” bet wins if the next roll is a crap.
- Croupier (dealer)
The casino employee who runs the game at a table: deals the cards or spins the ball, collects losing stakes and pays out winnings. In blackjack the dealer plays the house's hand by fixed rules, without making decisions; in poker between players the dealer only deals the cards and manages the pot, without playing.
D
- Decimal odds
The odds format most used in continental Europe, Romania included: the total amount returned for a stake of 1, stake included. At odds of 2.10, a winning bet returns the stake multiplied by 2.10; the implied probability is 1 divided by the odds, here 47.62%.
- Don't pass
The opposite of the pass line in craps: on the come-out roll it wins with 2 or 3, loses with 7 or 11, and 12 is usually a push; once a point is set, it wins if a 7 comes before the point. It pays 1 to 1 and has a house edge of 1.36%.
- Double down
The blackjack player's decision to double the stake after the first two cards, in exchange for receiving exactly one more card. The totals on which doubling is allowed (any two cards, only 9–11 or only 10–11) and whether doubling after a split is allowed differ from one venue to another.
- Double zero (00)
The second green pocket of American roulette, marked 00, which gives the wheel 38 pockets instead of 37. The payouts stay the same as on the European wheel, so the house edge rises to 5.26%; the five-number bet (0, 00, 1, 2, 3), found only on this version, has an even higher house edge of 7.89%.
- Doubling cube
The special die with faces 2, 4, 8, 16, 32 and 64, used in backgammon to double the value of the game. A player can propose a double before rolling; the opponent either accepts, and the game is worth twice as much with the cube passing to them, or declines and loses the game at its previous value.
- Dozen
A roulette bet on one of the three groups of 12 numbers: 1–12, 13–24 or 25–36; it pays 2 to 1. The chance of winning is 32.43% on a European wheel and 31.58% on an American one; zero makes the bet lose.
- Draw
The procedure by which the winning numbers of a lottery or keno game are chosen, either mechanically with balls or electronically with a random number generator. Each draw is independent of the previous ones: numbers that came up often or rarely in the past have the same chance in the next draw.
E
- En prison
A rule at some French roulette tables: when zero comes up, an even-money bet is not lost at once but stays “in prison” for the next spin; if it wins then, the stake is returned without winnings. Its effect on the house edge is close to that of la partage: the edge on these bets falls to almost half. Whether the rule exists and its details, such as what happens on a second zero, differ from one venue to another.
- Even-money bet (chance simple)
A roulette bet on half of the numbers from 1 to 36: red or black, odd or even, low (1–18) or high (19–36); it pays 1 to 1. Zero belongs to none of these groups, so on a European wheel the chance of winning is 48.65% and the chance of losing 51.35%. Some tables reduce the loss when zero comes up through the la partage or en prison rules.
- Expected value
The average result of a bet, found by multiplying each possible outcome by its probability and adding up the products. On European roulette, a stake of 100 on any of the standard bets has an expected value of −2.70. For almost every casino bet the expected value is negative for the player, and its size relative to the stake is the house edge.
F
- Field bet
A one-roll craps bet that wins if the total is 2, 3, 4, 9, 10, 11 or 12 and loses on 5, 6, 7 or 8. The 2 and the 12 pay more than the other numbers, and the exact payouts differ from one venue to another; with 2 to 1 on both 2 and 12, the house edge is 5.56%.
- Flop
The first three community cards, turned face up together in Texas hold'em and Omaha after the first betting round; the second betting round follows.
- Flush
A poker hand of five cards of the same suit (for example five hearts) that are not consecutive. It beats a straight and loses to a full house; of all possible five-card hands, 5,108 are flushes, or 0.20%.
- Fold
A poker player's decision to give up the hand, losing everything already put into the pot in that hand.
- Four of a kind
A poker hand made of four cards of the same rank, for example four 9s, and any fifth card. It beats a full house and loses only to a straight flush; of all possible five-card hands, 624 are four of a kind, or 0.0240%.
- Fractional odds
The traditional odds format in the United Kingdom and Ireland, written as a fraction showing the net win relative to the stake. Odds of 5/2 mean a win of 5 units for every 2 units staked, plus the stake back; the equivalent decimal odds are found by adding 1 to the value of the fraction.
- Full house
A poker hand made of three cards of the same rank and a pair, for example three 8s and two 5s. Between two full houses the one with the higher three of a kind wins; of all possible five-card hands, 3,744 are full houses, or 0.14%.
G
- Gambler's fallacy
The mistaken belief that, in a game of independent events, past results influence future ones, for example that after a run of reds on roulette black is “due”. A run of ten reds is rare when seen in advance (0.0743% on a European wheel), but once it has happened it does not change the next spin: the chance of another red stays at 48.65%. More in Gambler's fallacy.
- Gambling disorder (gambling addiction)
A disorder in which a person keeps gambling despite negative consequences for their finances, relationships, work or health, usually with a loss of control over the time and money spent. It is recognised as a disorder in the international medical classifications, under names such as “gambling disorder” or, in older terminology, “pathological gambling”. Specialised help exists; information on support is on the Responsible gambling page.
- Gammon
In backgammon, a win in which the loser has not yet borne off any checker when the winner has borne off all of them. It counts double a single win, multiplied by the value of the doubling cube if one is used.
H
- Handicap
A type of bet in which one team starts, for the purposes of the bet, with an advantage or a deficit in goals or points, to balance a match between unequal opponents. In Asian handicap, half-goal lines (for example 0.5) rule out a draw, and quarter-goal lines (for example 0.25) split the stake between two adjacent lines; the exact settlement rules differ from one bookmaker to another.
- Hard hand
In blackjack, a hand without an ace, or one in which the ace can only count as 1, for example 10 and 6 (“hard 16”). Unlike a soft hand, a hard hand of 12 or more can go over 21 with one more card.
- Hit
The blackjack player's decision to take another card. The player can keep taking cards until choosing to stand or going over 21 (bust); the dealer makes no such decision and draws by fixed rules, usually until reaching at least 17.
- Hit frequency
The share of a slot machine's spins that produce a payout of any size. It does not show how much the game returns: a machine can pay small amounts often or large amounts rarely with the same RTP. On the imaginary machine used as an example on this site, the hit frequency is 15.97% and the RTP 90.69%.
- Hole cards
The cards dealt face down to each poker player, seen only by that player: two in Texas hold'em, four in Omaha. In Texas hold'em the chance that the first two cards form a pair is 5.88%, and for a pair of aces it is 1 in 221.
- House edge
The share of each stake that the house keeps on average over the long run, resulting from the gap between a game's payouts and the true probabilities of its outcomes. On European roulette, for example, the house edge is 2.70% (1/37 of the stake); on American roulette it is 5.26%. It is the complement of RTP and describes the average over a very large number of bets, not the result of a single session. More in House edge and RTP.
I
- Implied probability
The probability expressed by odds, found for decimal odds as 1 divided by the odds: odds of 2.10 correspond to 47.62%. Because the odds include a margin, the implied probabilities of all the outcomes of an event add up to more than the whole: 104.81% in the example computed on this site.
- Insurance
A side bet in blackjack, available when the dealer's face-up card is an ace: the player stakes up to half the original bet, and the side bet pays 2 to 1 if the dealer has a blackjack. It is a separate bet on the dealer's hidden card, with a higher house edge than the main game, and it is not part of basic strategy.
J
- Jackpot
The largest payout of a game, usually for the rarest combination. It can be fixed, set in the paytable, or progressive. Its probability is very small, and part of the game's RTP is concentrated in it, so the ordinary payouts return less than the overall RTP suggests.
K
- Keno
A lottery-style game in which 20 numbers are drawn from 80, and the player picks a few numbers in advance, up to a maximum that differs between games. The payout depends on how many of the chosen numbers are drawn; the more numbers are picked, the smaller the chance of matching them all: 25.00% for one number, 0.0645% for five. Paytables differ from one game to another.
- Kicker
The card that is not part of the main combination of a poker hand but decides between two hands of the same type. For example, between two players who each hold a pair of aces, the one with the higher remaining card, the kicker, wins.
L
- La partage
A French roulette rule: when zero comes up, even-money bets lose only half the stake and the other half is returned. The rule lowers the house edge on these bets to 1.35%, from 2.70% without it. Whether it applies, and under what conditions, differs from one venue to another.
- Law of large numbers
The mathematical principle that, as the number of trials grows, the average result gets closer to the expected value. On European roulette, with equal stakes on an even-money bet, the chance of being ahead is 35.53% after 100 spins but only 0.33% after 10,000 spins. The law does not “correct” past runs: deviations are not made up, they become insignificant relative to the growing number of trials. More in Variance and the law of large numbers.
- Licence
An authorisation granted by a regulatory authority to organise gambling or to provide services connected with it. In Romania, licences are granted by ONJN: a class I licence covers organising gambling, and a class II licence covers suppliers of services to gambling organisers.
- Licensed operator
A company holding a valid licence to organise gambling, granted by the competent authority; in Romania, a class I licence granted by ONJN.
- Live betting (in-play)
Betting while a sporting event is under way, at odds that change during play according to the score, the time left and other events in the game. Live odds include a margin like any others, and betting can be suspended for a while at decisive moments.
- Lottery
A game of chance in which participants buy tickets with numbers or combinations and the winners are decided by a draw. In a 6-from-49 lottery, a ticket has a chance of 1 in 13,983,816 of matching all 6 numbers. The share of takings returned as prizes is usually much smaller than in casino games.
M
- Margin (overround)
The part built into the odds that gives the bookmaker an average profit: the implied probabilities of all the outcomes of an event add up to more than the whole. In the example computed on this site, a match with three possible outcomes, they add up to 104.81%, so the margin is 4.81%. The size of the margin differs from one event to another and from one type of bet to another.
- Martingale
A betting system in which the stake is doubled after every loss, so that the first win recovers the previous losses plus one unit. On an even-money bet on a European wheel, the chance of ten losses in a row within one series is 0.13%, and over 100 series the chance of this happening at least once is 11.98%; the required stake grows exponentially and runs into the table limit or the bankroll. The system does not change the house edge; more in Betting systems.
N
- Natural (baccarat)
In baccarat, a hand totalling 8 or 9 with the first two cards. If either hand has a natural, no more cards are dealt and the result is settled at once.
- Near miss
A result in which the symbols of a large combination stop just next to the payline, or in which a single symbol is missing, giving the impression that a win was “close”. The result is a loss like any other and says nothing about the next spins; psychological research links such results to the urge to keep gambling.
O
- Odds
In betting, the number that shows how much a winning bet pays relative to the stake and, by implication, what probability the bookmaker assigns to the outcome. The same odds can be written in decimal, fractional or American format. Odds include a margin, so they do not reflect the true probabilities exactly; in casino games the word also means the payout ratio, for example 35 to 1 on a straight-up roulette bet.
- Odds bet
An additional craps bet placed behind a pass line, don't pass, come or don't come bet once a point is set, which pays exactly according to the true probabilities. The odds bet has no house edge (0.00%), but it cannot be placed on its own, and the underlying bet keeps its edge. The maximum allowed on the odds differs from one venue to another.
- Omaha
A community-card form of poker similar to Texas hold'em, in which each player receives four hole cards and must use exactly two of them together with exactly three of the five community cards. It is usually played as “pot limit”, where a raise cannot exceed the size of the pot.
- ONJN
The Oficiul Național pentru Jocuri de Noroc (National Gambling Office), the Romanian authority that licenses and supervises gambling. Official information is published on the ONJN website.
- Outs
The unseen cards that, if they appear on the board, complete the hand a poker player is hoping for. For example, with four cards of the same suit after the flop, there are 9 outs for a flush, and the chance of completing it by the river is 34.97%. The number of outs is the basis for working out pot odds.
- Over/under (totals)
A bet on whether a total in an event (goals, points, corners) will be over or under a figure set by the bookmaker, for example 2.5 goals. Half-point lines rule out a tie; on whole-number lines, a result equal to the line usually means the stake is returned.
P
- Pass line
The basic bet in craps: it wins with 7 or 11 on the come-out roll and loses with 2, 3 or 12; if a point is set, it wins if the point comes again before a 7. It pays 1 to 1, wins 49.29% of the time and has a house edge of 1.41%.
- Payline
The line across the reels on which a combination of symbols must appear to be paid, according to the paytable. Machines have anything from a single line to dozens of lines, and some pay combinations on adjacent positions without fixed lines; staking on more lines multiplies the amount put in on each spin.
- Payout
The amount a winning bet receives, usually expressed as a ratio to the stake: “35 to 1” means 35 units won for each unit staked, plus the stake back. On slot machines the payout is usually expressed as the total amount returned, stake included. The gap between the payouts and the true probabilities determines the house edge.
- Paytable
The list of a game's winning combinations and the payout for each, shown on the machine or in the game rules. The paytable shows how much each combination pays but not how often it appears, so the RTP cannot be worked out from it alone.
- Peek
The check the blackjack dealer makes, when the face-up card is an ace or a ten-value card, to find out whether the dealer has a blackjack before the players decide. If so, the hand ends at once and the players lose only their original stake, not amounts added by doubling or splitting. At tables without this check, the treatment of added amounts differs from one venue to another.
- Pip (pip count)
In backgammon, the unit of distance: one point moved by a checker. A player's pip count is the total distance all their checkers still have to travel before being borne off, and it shows who is ahead in the race; at the start of the game both players have the same count.
- Place bet
A craps bet on one of the numbers 4, 5, 6, 8, 9 or 10, which wins if the chosen number comes before a 7. The payout differs by number; on 6 and 8 it is usually 7 to 6, with a house edge of 1.52%.
- Player (baccarat)
One of the two hands dealt in punto banco, and the bet on it winning; the name does not refer to the person betting. The player bet pays 1 to 1 without commission, wins in 44.62% of hands and has a house edge of 1.24%.
- Point
In craps, a total of 4, 5, 6, 8, 9 or 10 thrown on the come-out roll. From then on the dice are rolled until the point comes again, in which case the pass line wins, or a 7 comes, in which case the pass line loses (“seven out”) and the dice pass to the next shooter.
- Pot
The sum of all the bets placed in a poker hand, won by the player with the best hand at the showdown or by the last player remaining. When a player is all-in, the bets that player cannot match form a separate “side pot”, contested only by the others. The house may take a rake from the pot.
- Pot odds
The ratio between the size of the pot and the amount a poker player must pay to stay in the hand. Compared with the chance of completing the hand, worked out from the number of outs, it shows whether calling has a positive or negative average result against the other players in the long run. The calculation does not involve the house, which takes its rake whoever wins.
- Probability
A measure of how likely an event is: a number between 0 (impossible) and 1 (certain), also written as a fraction or a percentage. When all outcomes are equally likely, the probability is the number of favourable cases divided by the total number of cases: of the 36 combinations of two dice, six give a total of 7, so the probability of a 7 is 16.67%. More in Probability basics.
- Progressive jackpot
A jackpot that grows by a small share of every stake placed on one or more linked machines or games until it is won, after which it goes back to a starting amount. The fund comes from the players' stakes, and the chance of winning it on any spin stays very small, however large the amount displayed.
R
- Raise
A poker player's decision to increase the largest bet in the current betting round, so that the others must match the new amount, raise in turn or fold. The minimum and maximum size of a raise depend on the betting structure: fixed limit, pot limit or no limit.
- Rake
The commission the house takes in poker played between players: usually a small share of each pot, sometimes with a cap, or a fixed fee for time at the table or for entry. The house does not play against the players, but the rake makes the total money left at the table shrink over time. Its size and how it is calculated differ from one venue to another.
- Random number generator (RNG)
The software that produces the results of electronic games (slot machines, electronic roulette, on-screen card games), so that each result is unpredictable and independent of the previous ones. Testing and certification requirements for these generators differ from one jurisdiction to another. A fair generator does not remove the house edge, which comes from the game's payouts, not from the generator.
- Reel
One of the rotating columns of a slot machine that carry the symbols. On modern machines the position at which each reel stops is decided by the random number generator, and the number of positions and the distribution of symbols are not visible to the player. On the imaginary machine used as an example on this site, each reel has 20 positions.
- River
The fifth and last community card in Texas hold'em and Omaha, followed by the last betting round and, if at least two players remain, by the showdown.
- Royal flush
The straight flush from 10 to ace (10, jack, queen, king and ace of the same suit), the highest hand in standard poker. There are only 4 such hands, one per suit, or 0.000154% of five-card hands.
- RTP (return to player)
The share of all stakes that a game pays back to players on average over the very long run. RTP and the house edge are complementary and add up to the whole stake: on European roulette the RTP is 97.30% and the house edge 2.70%. On slot machines the RTP is set for each game by its maker; it is a theoretical average, not the amount each player gets back.
S
- S17 and H17
Abbreviations for the rule the blackjack dealer follows with a “soft 17”, a soft hand of 17 such as ace and 6: under S17 the dealer stands, under H17 the dealer hits. H17 favours the house: with basic strategy and the other rules unchanged, the house edge computed on this site is 0.57% under S17 and 0.79% under H17. The rule in force is usually printed on the table.
- Self-exclusion
A measure by which a person asks, on their own initiative, to be barred from gambling for a set period, with one gambling organiser or several. The specific conditions (duration, how it is applied, whether it can be lifted early) are set by the applicable rules and can differ. Information on support is on the Responsible gambling page.
- Shoe
The box from which the dealer draws the cards in blackjack or baccarat when several decks are shuffled together, usually six or eight. The last part of the cards is not dealt: a cut card marks when the reshuffle happens, and its position differs from one venue to another.
- Showdown
The moment at the end of a poker hand when the remaining players show their cards and the best hand wins the pot. If all the other players fold earlier, the hand ends without a showdown and the last remaining player takes the pot without showing any cards.
- Six line (sixain)
A roulette bet on six numbers, two adjacent rows of three (for example 1 to 6), with the chip placed at the edge of the line between them; it pays 5 to 1. The chance of winning is 16.22% on a European wheel and 15.79% on an American one.
- Soft hand
In blackjack, a hand containing an ace counted as 11 without going over 21, for example ace and 6 (“soft 17”). Such a hand cannot go over 21 with one more card, because the ace can also count as 1.
- Split
The blackjack player's decision to separate a pair dealt as the first two cards into two separate hands, each with a stake equal to the original one. How many times a hand can be split, what happens to a pair of aces (usually each ace receives only one card) and whether doubling after a split is allowed are rules that differ from one venue to another.
- Split (cheval)
A roulette bet on two numbers next to each other on the layout, with the chip placed on the line between them; it pays 17 to 1. The chance of winning is 5.41% on a European wheel and 5.26% on an American one.
- Stake
The amount put at risk on a bet or a hand, which the player loses if the bet loses. Tables and games usually have a minimum and a maximum stake (a table limit), set by the rules of the venue or of the game.
- Stand
The blackjack player's decision to take no more cards and keep the current total. Once every player has stood or gone over 21, the dealer plays out the house's hand by fixed rules.
- Standard deviation
The square root of the variance, expressed in the same unit as the result, for example in stakes. It shows how far from the average the result of a bet usually lands: on European roulette it is 1.00 times the stake for an even-money bet and 5.84 times the stake for a straight-up bet. Over a series of bets, the standard deviation grows with the square root of the number of bets, while the average loss grows in proportion to it.
- Straight
A poker hand of five cards of consecutive ranks that are not all of the same suit, for example 5, 6, 7, 8, 9; the ace can be high (10 to ace) or low (ace to 5). Of the 2,598,960 possible five-card hands, 10,200 are straights, or 0.39%.
- Straight flush
A poker hand of five consecutive cards of the same suit, for example 5, 6, 7, 8, 9 of clubs. The highest of them, 10 to ace, is called a royal flush; leaving it aside, there are 36 possible straight flushes, or 0.0014% of five-card hands.
- Straight up (plein)
A roulette bet on a single number, zero included, paying 35 to 1. On a European wheel, with 37 pockets, the chance of winning is 2.70%; on an American wheel it is 2.63%. The house edge is the same as on most other bets of that version.
- Street (transversale)
A roulette bet on the three numbers of one row of the layout (for example 1, 2 and 3), with the chip placed at the edge of the row; it pays 11 to 1. The chance of winning is 8.11% on a European wheel and 7.89% on an American one.
- Surrender
An option available only at some blackjack tables, by which the player gives up the hand after the first two cards and loses only half the stake. “Late surrender” is allowed only after the dealer has checked for blackjack; “early surrender”, before that check, is rare.
- Symbol
An image on the reels of a slot machine (fruit, numbers, letters, themed signs) whose combinations decide the payouts. Symbols appear with different frequencies: on the site's imaginary machine the 7 takes up a single position out of 20 on each reel, and the 7-7-7 combination has a probability of 1 in 8,000. Some games have special symbols with their own rules, described in the paytable.
T
- Table limit
The minimum and maximum stakes accepted at a gaming table, set by the venue and usually displayed at the table. The maximum limit prevents systems that raise the stake after losses, such as the martingale, from continuing indefinitely.
- Table (Romanian backgammon)
The Romanian name for the two-player games played on a board of 24 points, with 15 checkers each and two dice, of which backgammon is the most widely known. The result depends both on the dice and on the players' decisions; the variants differ in the starting position of the checkers and in the movement rules.
- Texas hold'em
The most widespread form of poker: each player receives two hole cards, and five community cards are turned on the table, with four betting rounds. The best five-card hand made from any of the seven available cards wins. There are 1,326 possible two-card starting combinations.
- Third-card rule
The set of fixed rules in punto banco that decides whether the player and banker hands receive a third card. If neither hand has a natural, the player hand draws on a total of 0–5 and stands on 6 or 7, while the banker's decision depends on its own total and on the player's third card. Nobody chooses: the dealer applies the rules.
- Tie
The bet in punto banco that the banker and player hands will have the same total. It usually pays 8 to 1 and wins in about 9.52% of hands, which gives it a house edge of 14.36%; some tables pay differently. On a tie, bets on banker and player do not lose but are returned.
- Tournament (poker)
A form of poker in which players pay a fixed entry fee, receive the same number of tournament chips and play until one player has won them all, with blinds that rise at set intervals. Prizes go to the players who stay in longest, according to a structure announced in advance; the organiser keeps part of the fees.
V
- Variance
A measure of how widely results spread around the expected value: the higher the variance, the further short-term results can stray from the average, in either direction. Two bets with the same house edge can have very different variance: on European roulette the standard deviation per spin is 5.84 times the stake for a straight-up bet and 1.00 times the stake for an even-money bet. Variance does not change the average loss, only how far from it a session's result can land. More in Variance and the law of large numbers.
- Volatility
A term used mainly for slot machines to describe a game's variance: how rare and how large its wins are. A high-volatility game pays rarely but sometimes large amounts, a low-volatility game pays often but small amounts; the RTP can be the same in both cases. Labels such as “low”, “medium” or “high” have no standard definition and differ from one maker to another.
Z
- Zero
The green pocket of the roulette wheel, marked 0, which is neither red nor black and counts as neither odd nor even for betting. Zero (and, on the American wheel, double zero) is the source of the house edge: payouts are set as if the wheel had only 36 numbers. On a European wheel the result is a house edge of 2.70%.