Poker is a card game in which players wager on the outcome of a hand. It is played in many variants. The rules and jargon of poker vary from one variation to another, but the basic principle remains the same: players place bets into a central pot during each betting round, and the player with the highest-ranking hand wins.

Depending on the rules of the game, one or more players must place an initial amount into the pot before the cards are dealt; these are known as forced bets. These are usually in the form of antes or blind bets. Once the cards have been dealt, each player may choose whether to call (match) the previous high bet or raise it. In some poker variants, the raise must be at least double the previous high bet, or all of the player’s chips in his or her stack (an “all-in” bet).

After a player calls or raises a bet, other players may choose to place additional bets into the pot; this is known as raising the pot. A player who does not want to raise the pot may choose to fold his or her hand.

There are several types of poker hands, and the rank of each is determined by its odds. The highest hand is five of a kind. The second highest hand is a straight, and the third highest hand is three of a kind. Four of a kind is the fourth highest hand, and a pair is the lowest hand. Ties are broken by the highest unmatched card, or secondary pairs (in the case of a full house).

A game of poker can be played with 2 to 14 people. In cash games, the ideal number of players is 6 or 7 people. In tournaments, the numbers of players are often larger. In general, the more players in a tournament, the higher the stakes will be.

The game of poker became popular in the early 21st century because of the rise of online gambling and the invention of the hole-card camera, which made it possible for spectators to follow the action and drama of the game. It is now a worldwide spectator sport, and broadcasts of major events such as the World Series of Poker and the World Poker Tour draw huge audiences. The game is also popular in casinos and private homes. It has been called the national card game of the United States, and its play and jargon are widely incorporated into American culture.