Blackjack is a card game in which the player aims to get a higher hand value than the dealer without going over 21. The game is played with one or more standard 52-card decks. Cards are valued according to their face value, with the jack, queen, and king being worth 10 points and the aces being worth either 1 or 11. The rules of blackjack vary from casino to casino, but most games follow a basic strategy that minimizes the house’s edge over time.
In a standard game, each player places an initial bet before the dealer deals them two cards. The players can choose to hit (receive more cards) or stand (keep their current hand). The dealer also receives two cards, but only one is faced up. If a player has a blackjack, the hand wins immediately unless the dealer also has a blackjack. In that case, the hand is a push.
A player may make additional bets on their hand to improve it, such as an insurance bet. The insurance bet is equal to half the player’s original bet and pays 2-1 if the dealer has blackjack. Whether to take the insurance bet is a personal decision that each player must make for himself.
Most blackjack games follow a basic strategy that minimizes a casino’s edge over the long run, though some players deviate from it. Those deviations increase the house edge, but they don’t affect the probability of the dealer busting. A player who follows basic strategy will lose less than 1% of his money on average over the long run, making blackjack one of the lowest-edge casino games.
Some casinos offer different variations on blackjack, including side bets and varying payouts for blackjack. Some variants of the game pay 6 to 5 instead of the standard 3 to 2 for a winning blackjack, which increases the house edge by about 1.4%.
Another change is allowing the player to resplit aces after splitting them, which decreases the house edge by about 0.3%. The variation in the house edge between the different blackjack games is mainly due to differences in the rules and conditions that apply to each game.
The game of blackjack is the most popular casino banking card game, and it descends from a global family of games that includes the European games vingt-et-un and pontoon and the Chinese game Ochko. The name “blackjack” comes from the fact that a natural consisting of an ace of spades and a black jack was once paid extra in some casinos. The term was later adopted by American gaming equipment distributor John Scarne, but he offers no documentary evidence for his claim that the inscription “Blackjack pays 3 to 2” appeared on felt table layouts as early as 1919.