Every blackjack term you need to understand the game, the strategy charts, and what counters and dealers are talking about. Bookmark this; it’s the reference the rest of our blackjack guides point back to.
Blackjack vocabulary spans three worlds: the game itself, the strategy and math layer that sits on top, and the casino floor language used by dealers, pit staff, and counters. We’ve covered all three below, alphabetically. Terms that have their own dedicated guide on PayoutCompass link out to the deeper coverage.
How to use this glossary
Jump to a letter using the nav below. Use your browser’s find function (Ctrl+F or Cmd+F) to look up specific terms. Bold terms inside a definition mean that word has its own entry elsewhere in the glossary.
A · B · C · D · E · F · H · I · L · M · N · P · R · S · T · U · V · W
A
Ace. The most flexible card in blackjack. Counts as either 1 or 11, whichever helps the hand more. A hand containing an ace that can still count as 11 without busting is a soft hand.
Action. The total amount wagered over a session, regardless of wins or losses. Casinos use action (not net loss) to calculate comp value.
Anchor. The last seat at the table, immediately to the dealer’s right. Plays last before the dealer. Also called third base.
B
Back-off. When casino staff politely ask a suspected counter to stop playing blackjack (often allowed to play other games). One step short of a formal trespass ban. Discussed in our card counting guide.
Bankroll. The total money set aside for blackjack play. Session bankroll is what you bring to a single visit; total bankroll is your overall blackjack budget. Sizing covered in our bankroll management guide.
Basic strategy. The mathematically optimal play for every blackjack hand against every dealer up-card, calculated by computer simulation. Cuts the house edge to roughly 0.5% under standard rules. The full chart lives in our basic strategy guide.
Bet spread. The ratio between a counter’s smallest and largest bets in a session. A 1-to-8 spread means the biggest bet is eight units when the count is high, one unit when it isn’t. Larger spreads earn more but attract more heat.
Blackjack. Two meanings. (1) The game itself, also called 21. (2) The specific hand of an ace plus a ten-value card on the first two cards (a “natural”), which pays 3:2 in proper rules, or 6:5 in tourist-trap rules.
Burn card. The first card after a shuffle, removed from play without being shown. Casinos use it to disrupt early-shoe advantage techniques.
Bust. Going over 21. An automatic loss, regardless of what the dealer’s final total turns out to be. This is the structural advantage the casino has: the player acts first, and busts lose immediately.
Buy-in. The chips purchased when sitting down at a table. The initial cash exchange.
C
Card counting. A legal advantage-play technique that tracks the ratio of high cards to low cards remaining in the shoe, allowing the player to bet more when the deck favours them. Fully covered in our card counting guide.
Color up. Exchanging a stack of smaller chips for fewer larger ones, usually before leaving a table.
Comp. Complimentary perks (room, food, credit) given by casinos to players based on tracked action. Skilled flat-betting can earn comps worth more than the expected loss, a form of casual advantage play.
Continuous Shuffle Machine (CSM). An automatic shuffler that immediately returns played cards to the shoe and reshuffles continuously. Functionally identical to dealing from a fresh shoe every hand. Kills card counting completely.
Cut card. A coloured plastic card inserted into the shoe after the shuffle. When the dealer reaches it, the current hand finishes and then the shoe is reshuffled. The cut card position controls penetration.
D
DAS (Double After Split). A favourable rule allowing the player to double down after splitting a pair. Worth about 0.13% of house edge to the player.
Deck penetration. The percentage of the shoe dealt before the shuffle, controlled by the cut card position. Deeper penetration (more cards dealt before reshuffle) is much better for counters; 75%+ penetration is rare and prized.
Deviation. A play that departs from basic strategy because the count is extreme enough to make a different action correct. The canonical list is the Illustrious 18.
Double down. Doubling the original bet in exchange for committing to take exactly one more card. Used on strong starting hands like 10 or 11 against weak dealer cards.
Double down rescue. A Spanish 21 rule allowing the player to surrender after doubling. Available on no other major variant. Covered in our Spanish 21 guide.
E
Early surrender. Surrendering before the dealer checks for blackjack. Much more valuable to the player than late surrender (worth about 0.24% of house edge). Now rare; almost all surrender rules today are late surrender.
Edge. The mathematical advantage one side has over the other. House edge is what the casino expects to win per dollar wagered, on average, over many hands. Player edge (when a counter has it) is the reverse.
Even money. The option to take a 1:1 payout on a player blackjack when the dealer’s up-card is an ace, instead of waiting to see if the dealer also has blackjack (a push). Mathematically identical to taking insurance on a blackjack. Bad bet in almost every case.
F
Face cards. Jack, Queen, King. Each counts as 10 in blackjack.
First base. The first seat at the table, immediately to the dealer’s left. Plays first.
Five-card Charlie. A rare bonus rule where any five-card hand totalling 21 or less is an automatic win. Worth significant value to the player when offered.
Flat bet. Betting the same amount on every hand. The opposite of a bet spread; the typical play style for non-counters.
H
H17. Rule where the dealer hits soft 17 instead of standing. Adds 0.21% to the house edge compared to S17.
Hand signal. The standard physical signal used at a live table to indicate hit, stand, double, or split. Covered in our hand signals guide.
Hard hand. Any hand without an ace, or with an ace that must count as 1 to avoid busting. The opposite of a soft hand; less flexible to play.
Heat. Attention from casino floor staff, usually directed at suspected counters. Visible heat (pit bosses standing behind you, watching your bets) is a sign to slow down or leave.
Hi-Lo. The standard card counting system, popularised by Edward Thorp in Beat the Dealer. Cards 2-6 count +1, 7-9 count 0, 10s and aces count -1. Detailed in our card counting guide.
High roller. A player who bets large amounts. Also called a whale. Treated with deference (and many comps) by casinos.
Hit. Take another card. The most common player action.
Hole card. The dealer’s face-down card. In standard blackjack the dealer has one up-card and one hole card. In British Pontoon, both dealer cards are hole cards.
Hole carding. Advantage play technique of exploiting a dealer who inadvertently exposes their hole card. Legal in most jurisdictions without electronic aid. Covered in our advantage play guide.
House edge. The percentage of every wager the casino expects to keep over the long run. In standard 6-deck blackjack with basic strategy, around 0.5%. In 6:5 blackjack, around 1.9%.
I
Illustrious 18. Don Schlesinger’s list of the 18 basic strategy deviations that carry the most value for a card counter. Full breakdown in our Illustrious 18 guide.
Index play. A specific count value at which a counter deviates from basic strategy. For example, “insurance at +3” means take insurance when the true count reaches +3 or higher.
Insurance. A side bet offered when the dealer’s up-card is an ace, paying 2:1 if the dealer has blackjack. Mathematically a bad bet for anyone not counting. Covered in our side bets guide.
L
Late surrender. Surrendering after the dealer has checked for blackjack (and not had it). The standard surrender rule offered today. Less valuable than early surrender. Full guidance in our surrender guide.
Live dealer. Online blackjack played against a real human dealer streamed from a studio, using physical cards. The streamed alternative to RNG (digital) blackjack.
M
Martingale. A betting progression where the player doubles their bet after every loss, planning to recoup losses on the eventual win. Mathematically broken; covered in our betting systems guide.
Match the dealer. A Spanish 21 side bet paying out when the player’s initial cards match the dealer’s up-card by rank. Around 3% house edge; skip it.
N
Natural. A two-card 21 (ace plus ten-value card) dealt on the first two cards. Also called a blackjack. Pays 3:2 in proper games.
P
Pair. Two cards of the same rank on the first two cards dealt. Eligible to be split into two separate hands.
Penetration. See deck penetration.
Pit boss. The casino floor supervisor responsible for a “pit” of tables. The person watching for unusual betting patterns or suspected counting.
Push. A tie between player and dealer. The player neither wins nor loses; the original bet is returned.
R
Resplit. Splitting a pair, then splitting again when another matching card is dealt. Allowed in most blackjack games up to three or four hands.
Risk of ruin. The mathematical probability of losing your entire bankroll given your edge and bet size. Even players with a real edge face significant risk of ruin without proper bankroll management.
RNG (Random Number Generator). The software algorithm that “deals” digital online blackjack. Reshuffles after every hand, which makes card counting useless in RNG games.
Running count. The unadjusted total when card counting, before dividing by decks remaining. Becomes the true count after conversion.
S
S17. Rule where the dealer stands on soft 17. The player-friendly variant; 0.21% better than H17.
Shoe. The plastic box holding multiple decks from which the dealer deals. Common configurations are 6 or 8 decks; single-deck and double-deck games (dealt from hand) are rarer.
Shuffle tracking. Advantage play technique of following clumps of high cards through a riffle shuffle. Requires obsessive practice and shoe-specific shuffle analysis. Covered in our advantage play guide.
Side bet. Any optional wager offered alongside the main game (insurance, 21+3, Perfect Pairs, Match the Dealer, etc.). Almost all carry much higher house edges than the main game. Detailed in our side bets guide.
Soft hand. Any hand containing an ace that can still count as 11 without busting. Soft 18 (A,7) is the textbook example. More flexible to play than a hard hand of the same total.
Split. Separating a pair into two hands, each with its own bet matching the original. Standard rules allow splitting up to four hands total (three resplits), with aces usually limited to one card each.
Stand. Stop taking cards. The player action that ends a hand without going further.
Stiff hand. Any hard total between 12 and 16. Often loses if stood on, often busts if hit. The most uncomfortable hands in blackjack, and the ones basic strategy is most valuable for.
Surrender. Forfeiting half the original bet to end the hand without playing it out. Available on some tables. Detailed in our surrender guide.
T
Toke. A tip to the dealer, typically given as a small bet placed for the dealer rather than cash. Optional but customary at live tables.
Tournament. A blackjack format where players compete against each other for prize pools rather than against the casino for their own bankroll. Requires its own strategy. Covered in our tournament guide.
True count. The running count divided by the estimated decks remaining in the shoe. The number that actually dictates a counter’s betting and deviation decisions.
21+3. A common side bet combining the player’s two cards with the dealer’s up-card and paying out for poker-style combinations (flush, straight, three-of-a-kind). Covered in our side bets guide.
U
Up-card. The dealer’s face-up card. The single piece of information the player has about the dealer’s hand before deciding their own play.
V
Variance. The natural swings around expected value. High variance means big swings in both directions; blackjack has moderate variance compared to slots or roulette but enough to produce winning and losing streaks that feel anything but average.
W
Whale. A very large bettor. Treated with extreme deference by casinos.
Wonging. Back-counting a table from outside (not playing) until the count goes favourable, then sitting in. Named after Stanford Wong. Increasingly difficult as casinos have introduced “no mid-shoe entry” rules to block it.
Now that the vocabulary is sorted, the basic strategy guide is the highest-value next read, followed by the rules guide if you need the gameplay basics. For the counter-curious, the card counting guide and the Illustrious 18 deviations go deep. Back to the full Blackjack guide, or jump to where to play in Malaysia.