Poker is a card game in which players place chips (representing money) into the pot when betting on their hand. The goal is to have the best five-card poker hand. While the outcome of any particular hand in poker significantly involves chance, a player’s long-run expectations are determined by their decisions made on the basis of probability, psychology and game theory.
The poker rules vary among the different variants of the game but all share some common features. Each poker hand comprises a combination of cards that ranks in value in inverse proportion to its mathematical frequency: the more unusual the combination, the higher the rank. The value of a poker hand may be increased by bluffing, whereby the player bets that they have a superior hand and win if other players call the bet.
In some forms of poker a single card called the “bug” is used as an extra wild card and counts as any suit. A poker game may be played with as few as two or as many as 14 players. A game with more than 12 players is generally played in a tournament format.
Poker has its roots in a wide range of earlier vying games, including pochen, Brelan, Flux and Post (German, 16th – 18th centuries), and Brag (18th century). Research into the history of poker has resulted in the development of a set of definitive rules, which first appeared in 1904. Poker is now widely enjoyed worldwide.