Blackjack is a game where players compete against the dealer to win a hand that totals closer to 21 than the dealer’s without going over. The game is played with one or more 52-card decks and each card has a value represented by the number on the card (for example, face cards are worth 10 while aces are worth 1 or 11). The player’s goal is to beat the dealer by getting a higher value hand than theirs or, more specifically, by acquiring an ace plus a ten-value card in their first two hands.

The game is generally played on a semicircular table that can accommodate varying numbers of players (or “spots”). Typically the dealer is stationed behind the table and chip rack and the players sit around the perimeter of the table. The game is regulated by a set of rules that define when the dealer must take a hit, stand, double down, or split and which cards count as high and low. The basic game has a very small house edge that can be reduced to almost zero with skillful play, but this requires extensive study.

Some casinos have introduced some variations to the game. For example, many of them have begun to pay 6 to 5 on blackjacks, which increases the house edge and makes counting cards almost impossible. This has been a major source of anger for longtime blackjack players.

Another common variation is to remove all of the ten-value cards from the shoe, which reduces the chances of a player getting a blackjack (a two-card hand that includes an ace and a ten-value card). This makes it harder for the player to make good decisions.

If the dealer shows an ace up, some games allow the players to place insurance bets of up to half their bet amount. These bets are placed on an “insurance bar” above the players’ chips. If the dealer has a blackjack, the insurance bet pays 2 to 1. In some games, the dealer will collect the insurance bets before playing any of his or her cards.

In some casino card games, the player may choose to add an additional wager to his or her initial bet by splitting, doubling down, or requesting extra cards. These side bets are usually based on the player’s point total and the dealer’s visible card. Adding these wagers can dramatically increase the player’s odds of winning, but the risk/reward is very high.

In most casino card games, the house has a statistical advantage that will eventually play out in the long run. However, blackjack is one of the few that has a large element of player choice and decision making that can reduce this advantage to a very small percentage. This is accomplished through a process known as “basic strategy,” which determines when to hit or stand, when to double down, and when to split. In general, a player will want to increase their bet size in favorable situations and decrease it in unfavorable ones.