Poker is a card game in which players compete for an amount of money or chips contributed by the players themselves (called the pot). Each round of betting ends when all the players have either called, raised, or folded.
Poker has many variants, but all of them share certain key features. A poker hand consists of five cards. The value of a hand is in direct proportion to its mathematical probability; the more unlikely a combination of cards is, the higher the hand rank. Players may bluff by betting that they have a strong hand when they do not, hoping to induce other players to call their bets with weak hands. Players may also win by calling other players’ bets with superior hands and exposing them.
In addition to evaluating their own hands, poker players must make predictions about their opponents’ intentions. Often, this requires understanding how other people perceive the game and responding to cues such as body language and facial expressions. This is why professional poker players often appear calm and confident, even when they have a poor hand.
In some games, a player will put all of their remaining chips into the pot — this is called going all-in. There are rules for how this works, depending on the variant of poker.