Poker is a card game in which players bet with chips that they have placed into the pot (a shared pool). Each player must place at least one forced bet in each betting interval. In addition to these forced bets, players may place additional chips into the pot for bluffing or other strategic reasons. While the outcome of any particular hand largely involves chance, a player’s long-run expectations are based on his or her decisions chosen on the basis of probability, psychology, and game theory.

The players’ hands are revealed after each betting round and the highest hand wins the pot. During the betting rounds, each player must decide whether to play (play a hand of at least a pair) or fold his or her cards. In some games the player must also decide whether to bluff, and if so, how much to bluff.

There are many variations of the game, but all involve putting some money into a common pool for the purposes of betting and raising. A player must either call the current bet (match it) or raise it by an amount specified in the game rules, usually by a multiple of the previous raise.

Some games use a special fund called a “kitty” to pay for things such as new decks of cards or food and drinks. Any chips left in the kitty when the game ends are divided equally among all remaining players. However, if a player drops out of the game before its end, he or she forfeits any rights in the kitty.