Blackjack is a game that uses one or more 52-card decks. The goal is to get cards that add up to 21 or close to it without going over. The dealer also gets two cards and must act according to a set of rules. Some of those rules are based on probability. Players can increase or decrease their bets depending on the situation, and some players use card counting to help tilt the odds in their favor.

The first thing a player must do when playing blackjack is to select a seat. Typically, blackjack tables allow for five to seven players. If there is an open spot, the player may assume it’s theirs unless a coat or chips are holding the spot for another player. Players should avoid joining a table that is already in progress (unless they’re told it’s okay by the pit boss or the other dealers at the table).

After selecting a seat, the dealer will deal each player two cards. If a player has a pair of matching cards, they can choose to split them and create two new hands. This doubles the player’s original bet. Then they can continue playing their original hand or make a separate bet on each of the new hands.

Some casinos offer a side bet called insurance, which pays out 2 to 1 if the dealer has a blackjack. A dealer must ask players if they want to take insurance before the first player plays their hand. Players who do not want to take insurance can leave the table or play other casino games.

When a player has a total that is higher than the dealer’s, they should stand. Otherwise, they should hit. Taking the risk of busting on 16 is not worth the chance that the dealer might have a better hand. Players who hit should be careful not to go over 21, as they will lose if they do.

Mathematical analysis has shown that for each combination of a player’s hand and the dealer’s up card, there is a single play that results in the highest probability of winning. This is known as basic strategy, and it should be used to guide each decision.

Many blackjack players ignore the basic strategy, and they end up making bad decisions. Some even get caught up in the strategies of other players at the table, which can lead to big losses. Fortunately, it is possible to learn some simple math and apply it to blackjack, which will give you a better chance of beating the house.