A card game where players place chips (representing money) into a common pot, and then gamble for winning hands. There are many different variations of poker, all with slight differences in rules and strategy. Although the outcome of any individual hand largely depends on chance, poker is a game in which players can make strategic decisions on the basis of probability, psychology, and game theory. A player’s choice of bet size, for example, is influenced by the expectation that calling his opponent’s bet will yield a positive expected return.

The game is played with one or more cards dealt face down to each player, followed by a number of betting intervals determined by the rules of the particular variant being played. The player to the left of the dealer is called the button, and has the privilege or obligation to bet first during a betting interval. Other players may call or raise the bet, depending on the specific game.

While any combination of five cards can make a poker hand, the highest ranking is a royal flush (A, K, Q, J, and 10 of the same suit), followed by a straight flush (5 consecutive cards of the same suit), four of a kind (4 cards of the same rank), and a pair (3 matching cards). Ties are broken by the highest unmatched card, or, in the case of a full house (2 pairs), by the higher of the two hands.