Blackjack is a card game that can be played by one or more players against a dealer. It uses one or more standard 52-card decks. Each card has a value, either the number on the card or a face, or an ace (which can count as one or 11). The object of the game is to build a hand that gets as close as possible to 21 without going over. A player may choose to hit or stand, and they can double down or split their cards. Some casinos offer side bets on the dealer’s up card, and some allow players to “back count”, a practice named after blackjack author Stanford Wong, which involves watching the cards being played and only sitting down to play when the count is favorable.

The game is regulated by law in most states, but it is still considered gambling and the house has a statistical advantage that will play itself out over time. Unlike most casino games, blackjack allows the player to reduce this edge by playing according to a set of rules known as basic strategy. Basic strategy determines when to hit and when to stand, and it also identifies which hands are worth splitting or doubling down. It also explains how to correctly count cards and when it is advantageous to do so.

A starting hand of two cards that total 21 is a “blackjack” or “natural” and beats all other hands, unless the dealer has a blackjack. If the dealer has a blackjack, the player and the dealer push, which means that neither wins or loses the original bet. The player can choose to buy insurance against the dealer’s blackjack, which pays out 2:1 but can only be made before the dealer exposes their up card.

Players can also choose to surrender their hand before the dealer exposes their up card. This is a good option when the player has a hand that is unlikely to win and they know that they will not be able to improve it. The dealer will then collect the player’s bet and return it to them.

The game is often played in private circles, bars, and in other social situations. It is also sometimes played on the internet. In this case, it is important to follow a series of standards and to ensure that the game is fair for all players. The rules of online blackjack vary from site to site, so it is important to know what you are getting into before you sign up for a game. Some sites even have special bonuses for new members. Those who enjoy playing blackjack can also join an online community to share their knowledge and make friends. This will help them to improve their skills and become more successful at the game. They can also learn from other members’ experiences and avoid making mistakes that will cost them money. These online communities can also be helpful in finding a suitable casino for their gaming needs.