The blackjack glossary

Blackjack has a small working vocabulary and a much larger surrounding folklore. These one hundred and twelve terms describe the game, the table, the people around it and its mathematics. Familiarity with the words helps you ask precise questions; the connected guides explain how to use the answers. Rules below describe conventional blackjack unless a variation is explicitly identified.

Reading your hand

Start with the rules and soft hands. Bicycle’s introduction explains card values and naturals; Wizard of Odds distinguishes a split twenty-one from blackjack.

1. Natural / blackjack. An ace and a ten-value card in the initial, unsplit two-card hand. A natural ordinarily outranks a twenty-one made by drawing or splitting. Its winning payout depends on the table.

2. Twenty-one. A hand totalling 21. It may be a natural, a hand made with three or more cards, or a hand made after splitting. The total alone does not establish a blackjack payout.

3. Ten-value card. A ten, jack, queen or king. These share a blackjack point value even though their ranks differ. Sixteen of every fifty-two cards are ten-value, which is why “assume the hole card is a ten” is a useful rule of thumb but not a probability.

4. Hard hand. A hand with no ace counting as eleven. Ace–six–ten is hard seventeen because the ace must count as one.

5. Soft hand. A hand with an ace counting as eleven without busting. Ace–six is soft seventeen. Another card may turn a soft hand into a hard one.

6. Bust. A total above 21 after aces have been counted appropriately. A player bust ordinarily loses immediately, even if the dealer later busts.

7. Pair. Two cards of the same rank; many blackjack games also permit splitting two different ten-value ranks. Check the table’s definition of a splittable pair.

8. Upcard. The dealer’s visible initial card. It is a principal input to a basic-strategy decision.

9. Hole card. A dealer card initially dealt face down. A no-hole-card game does not deal this concealed second card at the start.

10. Push. A tied result that returns the wager without profit or loss. Two naturals ordinarily push; an ordinary twenty-one does not ordinarily push a dealer natural.

11. Stiff hand. A hard total from twelve to sixteen: one that can bust on a single card yet is unlikely to win if it stands. Stiff hands are where basic strategy earns its keep, because the right answer depends entirely on the dealer’s upcard.

12. Pat hand. A hand on which you stand without drawing, conventionally any hard seventeen or more, or a soft nineteen or twenty. The dealer’s own stopping rule also produces a pat hand. The term says nothing about whether the hand will win.

13. Bust card. Informally, the card that takes a hand over 21, and, in table folklore, the card the dealer “would have” drawn had another player not taken it. The folklore is a myth: every card is equally likely to sit in any position.

Choosing an action

Follow the decisions through doubling, splitting, insurance and surrender. Availability is part of the rule set, not a player’s preference.

14. Hit. Request another card. If the hand remains playable, further choices depend on the cards and rules.

15. Stand. Finish drawing and keep the current total for settlement against the dealer.

16. Double down. Increase the wager, ordinarily by an amount equal to the initial stake, and receive exactly one more card. Eligible hands and whether smaller doubles are permitted vary.

17. Double for less. Doubling down with an additional stake smaller than the original bet, where the table permits it. You still receive exactly one card, so you accept the full restriction for a reduced reward; basic strategy treats a full double as the correct play whenever doubling is right.

18. Split. Separate an eligible two-card pair into two hands, adding a second stake. Each hand then plays under the table’s split rules.

19. Resplit. Split another eligible pair arising in a split hand. The maximum number of resulting hands and permissions for aces vary.

20. Resplit aces / RSA. Permission to split again when a split ace is dealt another ace. It is worth a small amount to the player and is absent at many tables, including the profile used on this site, where split aces receive one card each and no further decision.

21. DAS. Double after split. Permission to double an eligible split hand; it does not by itself authorise doubling split aces.

22. Surrender. End an eligible hand by giving up half the initial wager. It differs from standing, which keeps the full wager at risk.

23. Early surrender. Surrender available before dealer blackjack is ruled out, subject to the table’s restrictions. It differs materially from late surrender.

24. Late surrender. Surrender available after dealer blackjack has been ruled out. A dealer natural therefore prevents this escape.

25. Insurance. A separate bet on dealer blackjack, normally offered against an ace upcard. It ordinarily pays 2:1 and is limited to half the main stake.

26. Even money. An offered 1:1 settlement of a player’s natural against a dealer ace. Under conventional 3:2 rules, its payoff is equivalent to taking full insurance on that natural; it is not an extra bonus.

Reading a table and its rules

Use choosing a table to turn these labels into questions. The rule-variation reference treats payout, dealer behaviour and settlement procedures separately.

27. 3:2 / 6:5. Ratios describing profit on a winning natural. A $10 wager earns $15 or $12 respectively, with the original wager returned separately.

28. S17. Dealer stands on soft seventeen. The dealer also stands on hard seventeen.

29. H17. Dealer hits soft seventeen. The dealer still stands on hard seventeen; H17 does not mean hitting every seventeen.

30. Peek. A check of the dealer’s hole card for blackjack before ordinary player actions, when the upcard makes a natural possible.

31. ENHC. European no hole card. The dealer takes the second card after players act. Full ENHC settlement can lose doubles and split stakes to a dealer natural; ask whether extra wagers are protected.

32. Original bets only / OBO. A settlement provision protecting additional split and double wagers against a later dealer blackjack, with the original wager lost. Confirm the precise local handling, including busted hands.

33. Placard. The sign on the table stating the minimum and maximum bet, the natural payout and usually the dealer’s soft-seventeen rule and doubling permissions. It is the authoritative statement of the game; a rule not on the placard or the felt should be confirmed with the dealer before betting.

34. Table limits. The minimum and maximum stake accepted on the main wager. The minimum sets the cost of a session; the maximum caps any betting progression and limits how widely a counter can spread. Side bets commonly carry their own, lower limits.

35. Rule set / profile. The complete list of conditions a strategy chart assumes: deck count, dealer soft-seventeen rule, doubling and splitting permissions, surrender, peek and payout. This site’s charts use six decks, S17, double any two cards with DAS, no surrender, US peek and 3:2 naturals.

36. Deck count. The number of 52-card decks in play, from one to eight. Fewer decks favour the player when other rules are equal, by roughly half a per cent between single deck and eight decks, but single-deck tables often pair with a 6:5 payout that outweighs the benefit.

Table procedure and equipment

How a round actually unfolds is covered in casino etiquette. The cut-card analysis explains why the shuffle point is a mathematical matter and not merely a procedural one.

37. Shoe. The device holding cards for dealing, commonly used with several decks. “Shoe game” does not specify the payout or dealer’s soft-seventeen rule.

38. Cut card. A marker used to establish a stopping point for a dealt batch. The dealer completes play according to the table’s procedure before reshuffling.

39. Penetration. How much of the available deck or shoe is dealt before reshuffling. It matters to tracking the remaining composition; it does not describe how deeply cards are inserted into a machine.

40. Continuous shuffling machine / CSM. Equipment that repeatedly mixes returned cards into the available pool. It differs from a machine that prepares a separate batch for the next shoe. The cut-card analysis above explains the mathematical distinction.

41. Burn card. One or more cards removed from the top of a freshly shuffled deck or shoe and placed in the discard tray unseen before the first round. Burning prevents anyone who glimpsed the top card during the cut from using it; it does not alter the odds otherwise.

42. Discard tray. The clear holder, usually on the dealer’s right, where played cards are stacked until the shuffle. Counters estimate decks remaining by comparing the height of the discard stack with the known size of the shoe.

43. Pitch game. A single- or double-deck game dealt by hand, with player cards delivered face down. Players pick up the cards with one hand and signal by scratching or tucking them. Hand-held games can offer better penetration but are often paired with poorer rules.

44. Face-up game. The standard multi-deck arrangement in which player cards are dealt face up and must not be touched. Decisions are communicated by hand signals so that surveillance cameras can see them, and the dealer reads totals aloud.

45. First base. The seat immediately to the dealer’s left, which receives cards and acts first in every round. It offers the least thinking time and no information from other players’ draws.

46. Third base / anchor. The seat immediately to the dealer’s right, which acts last. It sees the most cards before deciding, which counters value, and it attracts unjustified blame when its draw “takes the dealer’s bust card”.

47. Hand signal. The physical gesture that communicates a decision: tapping to hit, waving to stand, and placing chips beside the bet with one or two fingers raised to double or split. Signals, not words, are what the cameras record, so most dealers insist on them.

48. Toke. Casino slang for a tip to the dealer, either handed over directly or placed as a small bet in front of your own wager that wins and loses with your hand. Tipping is customary in the United States and less so in the United Kingdom and Europe.

49. Colour up. Exchanging a stack of small-denomination chips for fewer larger ones, normally when leaving the table. The dealer announces the amount so the pit can record what leaves; you then cash the larger chips at the cage.

50. Marker. A line of credit extended by the casino to an approved player, drawn against at the table in exchange for chips and settled later. Markers are real debt, and gaming regulators treat an unpaid marker as seriously as a bounced cheque.

51. Chips / cheques. The tokens that stand in for money at the table. Regulators and casinos formally call value chips “cheques”; dealers must change cash into chips before you bet, and chips are redeemable only at the issuing casino’s cage.

52. Round. One complete cycle of a deal: bets placed, two cards to each hand, player decisions in order from first base, the dealer’s draw and settlement. House edge and standard deviation are usually quoted per round of one initial bet.

Variants and side bets

The site’s rules articles cover the major variants in detail. The side-bet index analyses each extra wager’s paytable and house edge separately.

53. Side bet. An optional wager with its own winning conditions and paytable, separate from beating the dealer in the main game. Side bets typically carry a house edge several times that of the main game and are settled on the initial cards only.

54. 21+3. A side bet combining the player’s two cards and the dealer’s upcard into a three-card poker hand, paying on a flush, straight, three of a kind or straight flush according to the table’s paytable. The house edge varies widely with the paytable.

55. Perfect pairs. A side bet paying when the player’s first two cards form a pair, with higher payouts for a same-colour pair and the highest for an identical “perfect” pair of the same suit. Multi-deck shoes are what make an identical pair possible.

56. Pontoon. The British home-game ancestor and casino cousin of blackjack. The dealer’s cards are hidden, a “pontoon” (ace plus ten-value) and a five-card trick pay 2:1, “twist” means hit and “stick” means stand. Australian casino Pontoon is instead a Spanish 21 variant.

57. Spanish 21. Blackjack played with 48-card decks from which the tens (not the picture cards) are removed, offset by liberal rules: late surrender, doubling on any number of cards, player twenty-one always wins and bonus payouts for 21 made of five or more cards or specific combinations.

58. Blackjack Switch. A variant in which you play two hands and may swap the second cards between them. In exchange, a natural pays 1:1 and a dealer total of 22 pushes all standing player hands rather than busting. Switching strategy is distinct from ordinary basic strategy.

59. Free Bet Blackjack. A variant in which the house funds the extra stake on most doubles and splits as a “free bet” token; if the hand wins, the free bet is paid as if real. The compensating rule is that a dealer 22 pushes all player hands still standing.

60. Double Exposure. A variant in which both dealer cards are dealt face up. The information is offset by a natural paying 1:1 and the dealer winning all ties except on a player natural. Strategy changes substantially because the dealer’s total is known.

61. Charlie rule. A bonus rule under which a hand of a stated number of cards, most commonly five, six or seven, wins automatically without busting. A five-card Charlie is a feature of some home and online games and almost no casino shoe games.

62. Match play. A promotional coupon, often issued to new or returning players, that the casino matches against a real wager of the same amount. A winning hand pays on both; the coupon is collected whether the hand wins or loses. Used once on an even-money bet, it has positive expectation.

Strategy and probability

Read basic strategy first, bankroll and variance for the money questions and card counting for composition-based play. The gambling glossary defines house edge relative to initial wagers; the variance analysis examines the spread of blackjack outcomes. The multi-deck strategy page is the published reference the site’s chart was checked against.

63. Basic strategy. A decision system based on your hand, the dealer’s upcard and the game rules, without tracking previously dealt cards. It seeks the best expected result among legal actions, not a guaranteed win.

64. Total-dependent strategy. The standard form of basic strategy, in which the decision depends only on the hand’s total (and whether it is soft or a pair) and the dealer’s upcard. It is what strategy charts and this site’s trainer present, and it captures nearly all the available value.

65. Composition-dependent strategy. A refinement that also considers which cards make up a total, such as standing on a three-card hard sixteen against a ten while hitting ten–six. The gain in a six-deck game is a few hundredths of a per cent; in single deck it is larger.

66. Expected value / EV. The probability-weighted average net result of an action or wager under stated assumptions. A positive outcome on one hand does not prove the action had positive EV.

67. House edge. Expected player loss expressed as a proportion of the initial wager under a specified rule set and playing strategy. Blackjack calculations commonly use initial bets rather than including every later double or split stake in the denominator.

68. Element of risk. House edge expressed as a proportion of the total amount wagered, including the extra stakes placed on doubles and splits, rather than of the initial bet alone. Because the denominator is larger, the element of risk for blackjack is slightly smaller than the conventional house edge.

69. Return to player / RTP. Theoretical expected return expressed as a percentage of wagering. On a matching accounting basis, it complements house edge to 100%. A quoted blackjack figure needs its rules, strategy and wagering basis; it does not predict the amount returned in a session.

70. Variance. The mathematical spread of results around their expectation, measured using squared deviations. Large swings can occur even with correct play; a run of losses does not make a win due.

71. Standard deviation. The square root of variance, in the same units as the bet. For a round of blackjack it is a little over one initial bet, roughly 1.15 under common rules, which is why a session’s result is dominated by luck and the edge emerges only over thousands of rounds.

72. Bankroll. Money set aside for play. A session budget is the portion allocated to a particular visit. Neither changes the probability of the next card.

73. Unit. The base betting amount a player uses to express stakes and results, such as “a £10 unit” or “up 30 units”. Bankroll requirements, bet spreads and win rates are quoted in units so they scale with the player’s stakes.

74. Risk of ruin. The probability of losing an entire bankroll before reaching a goal or before the edge has time to show, given a bet size, edge and variance. It applies properly only to a player with an edge; for a basic-strategy player it is eventually 100% if play continues indefinitely.

75. Kelly criterion. A rule for sizing bets in proportion to the player’s edge divided by the variance, which maximises the long-run growth rate of a bankroll. Full Kelly produces severe swings, so advantage players usually bet a fraction of it. With no edge, Kelly prescribes a bet of zero.

76. N0. “N-zero”: the number of rounds an advantage player must play for the expected profit to equal one standard deviation of results, after which the edge becomes more likely than not to show. It is calculated as variance divided by the square of the per-round expectation.

77. Flat bet. Wagering the same amount on every round regardless of previous results or the count. For a basic-strategy player it is the lowest-variance way to play at a given stake and loses no more in expectation than any pattern of varying bets.

78. Progressive betting. Any system that changes the bet size according to previous wins or losses rather than the composition of the shoe. Progressions reshape the distribution of results, often trading many small wins for occasional large losses, but cannot change the expected loss, which depends only on total money wagered and the house edge.

79. Martingale. The best-known progression: double the bet after each loss so that any win recovers all previous losses plus one unit. A losing streak of modest length meets the table maximum or the bankroll, at which point the accumulated loss cannot be recovered. It does not alter the house edge.

80. Gambler’s fallacy. The belief that a result becomes “due” after a run of the opposite result. Within a shoe the composition does change as cards leave it, which is what counting measures, but a run of dealer wins by itself says nothing about the next round.

Counting and advantage play

The counting introduction explains why counting begins with basic strategy and still leaves substantial uncertainty; the Wikipedia article summarises the history, systems and casino responses.

81. Card counting. Tracking the ratio of high to low cards remaining in a shoe in order to bet more when the composition favours the player and to adjust a few playing decisions. It uses a running tally, not memorisation of individual cards, and gives a small long-run edge rather than a prediction of the next card.

82. Advantage player. A player who uses legal methods, such as card counting, shuffle tracking, hole carding or promotional arbitrage, to play with a positive expectation. Casinos may refuse an advantage player’s business, but the methods themselves are not cheating.

83. Running count. The accumulated value assigned to observed cards by a counting system. In Hi-Lo, low cards add, tens and aces subtract, and sevens through nines are neutral. It summarises composition, not the next card’s identity.

84. True count. In systems such as Hi-Lo, the running count adjusted for the estimated decks remaining. Conventions for estimation and rounding matter. The counting introduction above explains why counting begins with basic strategy and still leaves substantial uncertainty.

85. Hi-Lo. The most widely taught counting system: 2 to 6 count +1, 7 to 9 count 0, tens and aces count −1. It is balanced, so a full deck sums to zero, and simple enough to maintain at casino speed while playing basic strategy.

86. Balanced / unbalanced count. A balanced count sums to zero over a complete deck and needs conversion to a true count; an unbalanced count such as KO or Red Seven starts from a non-zero figure so that the running count alone approximates the true count, trading accuracy for ease.

87. Index play. A deviation from basic strategy triggered when the true count reaches a stated number, the index. Standing on sixteen against a ten at a true count of zero or above is the best-known example. Indexes depend on the counting system and the rules.

88. Illustrious 18. Don Schlesinger’s list of the eighteen Hi-Lo index plays that provide most of the value available from strategy deviations, led by insurance at +3, sixteen against ten at 0 and fifteen against ten at +4. It is the standard starting set for counters learning to vary play.

89. Fab 4. Schlesinger’s companion list of the four most valuable surrender indexes in Hi-Lo, covering fourteen and fifteen against a ten, fifteen against a nine and fifteen against an ace. They apply only where late surrender is offered.

90. Bet spread. The ratio between a counter’s largest and smallest bets, such as 1 to 8. A wider spread earns more from favourable counts but is more visible to the pit; the spread, together with penetration and rules, largely determines a counter’s edge.

91. Back-counting / Wonging. Counting from behind a table without betting and joining only when the count is favourable, then leaving when it falls. Named after Stanford Wong. It raises the counter’s average edge and is countered by “no mid-shoe entry” rules.

92. Betting correlation / playing efficiency. Measures of how well a counting system’s tags track the true effect of card removal on, respectively, betting decisions and playing decisions. Hi-Lo scores highly on betting correlation and moderately on playing efficiency; no single-level system is perfect at both.

93. Shuffle tracking. Following clumps of high cards through an imperfect shuffle so that their likely position in the next shoe is known, then cutting or betting accordingly. It requires a trackable shuffle procedure and is far harder than counting; modern automatic shufflers largely defeat it.

94. Hole carding. Exploiting a dealer who inadvertently exposes the hole card while checking for blackjack or sliding it under the upcard. Using information the dealer shows is lawful in most jurisdictions; using a device or an accomplice to obtain it is not.

95. Heat. Attention from the pit or surveillance directed at a player suspected of counting: closer observation, a floor supervisor watching the bets, a phone call, or a change in the game such as an early shuffle. Experienced counters reduce heat with cover play and by moving on.

96. Backing off. The casino’s polite request that a suspected counter stop playing blackjack, usually delivered by a floor supervisor with words to the effect of “you’re welcome to play any other game”. It is the most common countermeasure and is distinct from barring.

97. Barring / trespass. Formally excluding a player from the casino, often with a read trespass warning so that a return can be treated as a criminal offence. Private casinos in most jurisdictions may do this to counters; New Jersey casinos may not, following the Uston ruling.

98. Cover play. Deliberate deviations from optimal counting play, such as a smaller spread, occasional “wrong” plays or a tip at a high count, intended to make a counter look like an ordinary gambler. Cover costs expectation and is a trade against heat.

99. Team play. Several counters working together, typically with low-stake “spotters” counting at many tables and a “big player” called in to bet large only when a count is high. The approach, made famous by the MIT teams, spreads bankroll risk and conceals the bet spread.

Casino floor and people

Casino etiquette covers how to deal with the staff and the other players; these are the words you will hear them use.

100. Pit / pit boss. The pit is the enclosed area between a group of tables where supervisors stand; the pit boss runs it, with floor supervisors beneath. They rate play, resolve disputes, authorise markers and comps, and are the people who deliver a back-off.

101. Surveillance / eye in the sky. The camera system and the staff who watch it. Every table is recorded, which is why hand signals exist, disputes are settled by reviewing tape, and bet patterns suggesting counting can be analysed after the fact.

102. Comp. A complimentary meal, room, show or other benefit given in proportion to a player’s theoretical loss, calculated from average bet, hours played and the house edge the casino assumes. Comps are a rebate on expected loss, not a gift; betting more to earn them costs more than they return.

103. Rating card / player’s card. The loyalty card presented at the table so that the pit can record your average bet and time played. Rated play earns comps and offers; it also gives the casino a record of your results and betting pattern.

104. High roller. A player whose stakes are large enough to attract personal attention from casino hosts: higher limits, private rooms and generous comps. The threshold varies by property; in a large resort it begins at several hundred pounds a hand.

105. Whale. Casino slang for the very largest players, whose single visits can swing a property’s quarterly results. Whales are courted with credit, flights and suites, and casinos sometimes negotiate custom rules or loss rebates with them.

106. VIP. The tier of players, and the rooms and programmes serving them, above the general floor. In most casinos VIP status is tied to rated play and comes with its own hosts, limits and sometimes better blackjack rules.

107. Ploppy (slang). An advantage player’s dismissive term for an uninformed recreational gambler who plays by hunches, follows betting systems and blames third base. It is jargon from the counting community, not a word to use at the table.

Online and tournament play

Live-dealer, RNG and social casino play and tournament strategy explain these settings; the terms below are the ones that differ from a standard casino table.

108. RNG blackjack. Software blackjack in which a random number generator produces the cards, in effect reshuffling every round. At a licensed operator the RNG is independently tested; the house edge is determined by the published rules, and no card counting is possible.

109. Live dealer. Online blackjack in which a human dealer at a studio table deals physical cards on a video stream and players bet through the interface. It is real-money gambling at the pace of a physical table, usually with shallow penetration and bet limits that defeat counting.

110. Social casino. A game played with virtual chips that have no cash value and cannot be withdrawn, often with optional in-app purchases of more chips. Because nothing is wagered, it is not gambling in the legal sense in most jurisdictions, though the strategy and the odds behave the same way.

111. Tournament. A format in which players compete against one another rather than the house, each starting with equal chips and the largest stack after a set number of rounds advancing or winning. Strategy differs sharply from ordinary play because the aim is to beat the other players’ totals, not to maximise expectation.

112. Tournament button / elimination / lammer. The button marks which seat bets first in a tournament round and rotates each hand, so betting position changes. Elimination rounds remove the lowest stacks at set hands. A lammer is the small marker used to track chips, buttons or a player’s status at the table.

Ready to connect words to choices? Open the trainer for individual decisions or the Las Vegas practice table for the flow of a round.