ActionThe total amount of money wagered over a session or a specific period. Casinos track your action to determine comp eligibility.BankrollThe total amount of money a player has set aside specifically for blackjack. Proper bankroll management is critical for surviving variance.Basic StrategyThe mathematically optimal set of decisions for every possible hand combination. Following basic strategy reduces the house edge to roughly 0.5%. Learn more → Bet SpreadThe ratio between your minimum and maximum bet. Card counters use bet spreads (e.g., 1-12) to increase wagers when the count is favorable.Blackjack (Natural)An Ace plus a 10-value card dealt as the initial two cards. Pays 3:2 at standard tables (avoid 6:5 tables).Burn CardThe card removed from the top of the shoe and placed in the discard tray before dealing begins. Standard practice in most casinos.BustGoing over 21. If you bust, you lose immediately regardless of what the dealer has. The dealer busts too, but your loss has already been collected.Card CountingA technique for tracking the ratio of high to low cards remaining in the shoe. Not illegal, but casinos will back you off if they detect it. Learn more → Color UpExchanging lower-denomination chips for higher-denomination ones when leaving a table. Standard casino etiquette.Continuous Shuffle Machine (CSM)A device that reshuffles dealt cards back into the shoe after every hand. Eliminates any counting edge and slightly increases the house advantage by dealing more hands per hour.Cut CardA colored plastic card inserted into the shoe to determine where the dealer stops dealing and reshuffles. Deeper placement means better penetration for counters.DAS (Double After Split)A rule allowing you to double down on a hand created by splitting. DAS reduces the house edge by about 0.14%. Most multi-deck games offer it. Learn more → Double DownDoubling your original bet in exchange for receiving exactly one more card. Most profitable on hard 10 and 11 against weak dealer upcards.Early SurrenderSurrendering before the dealer checks for blackjack. Rare and extremely valuable when available, reducing the house edge by about 0.39%.Expected Value (EV)The average amount you expect to win or lose per hand over an infinite number of trials. Basic strategy selects the action with the highest EV for each hand. Learn more → First BaseThe seat at the far left of the table, first to receive cards and first to act. No strategic advantage or disadvantage compared to other seats.Hard HandA hand with no Ace counted as 11, or a hand with no Ace at all. Hard 16 (e.g., 10-6) is one of the worst hands in blackjack. Learn more → HitRequesting another card from the dealer. You can hit as many times as you want until you stand or bust.Hole CardThe dealer's face-down card. In American blackjack, the dealer checks the hole card for blackjack when showing an Ace or 10.House EdgeThe mathematical advantage the casino has over the player, expressed as a percentage. With basic strategy on a standard game, it is roughly 0.26-0.5%. Learn more → InsuranceA side bet offered when the dealer shows an Ace. Pays 2:1 if the dealer has blackjack. The house edge on insurance is 7.4%. Almost never correct to take. Learn more → Late SurrenderSurrendering after the dealer checks for blackjack, forfeiting half your bet. Correct on hard 16 vs dealer 9/10/A and hard 15 vs dealer 10.NaturalAnother word for blackjack: an Ace plus a 10-value card as your first two cards.PenetrationHow deeply into the shoe the dealer deals before reshuffling. Measured in decks or percentage. Higher penetration benefits card counters.Pit BossA casino supervisor who oversees multiple blackjack tables. Watches for unusual betting patterns, dealer errors, and advantage play.PushA tie between the player and dealer. Your bet is returned. Pushes occur roughly 8% of the time with basic strategy.Running CountThe cumulative total of card values assigned by a counting system. In Hi-Lo, low cards add +1 and high cards subtract 1 from the running count. Learn more → ShoeThe device holding multiple decks of cards from which the dealer draws. Standard shoe games use 6 or 8 decks.Soft HandA hand containing an Ace counted as 11. Soft 17 (Ace-6) can become hard 7 if you hit and draw a high card. Soft hands allow more aggressive play. Learn more → SplitDividing a pair into two separate hands, each with its own bet. Always split Aces and 8s. Never split 10s or 5s. Learn more → StandKeeping your current hand and ending your turn. The dealer then plays their hand according to fixed rules.Stiff HandA hard hand totaling 12-16 that can bust with a single card. These are the hands where basic strategy matters most.SurrenderGiving up your hand and forfeiting half your bet. Only available at some tables. Correct on a few specific hands where your expected loss exceeds 50%.Third BaseThe seat at the far right, last to act before the dealer. Despite popular myth, the third base player's decisions have zero effect on other players' outcomes. Learn more → True CountThe running count divided by the number of decks remaining. Normalizes the count for multi-deck games and determines optimal bet size. Learn more → UnitA standard bet size used as a reference for bankroll management. If your unit is $25, a 4-unit bet is $100. Keeping units consistent helps track performance.UpcardThe dealer's face-up card. Your entire basic strategy decision depends on your hand total and the dealer's upcard.