Poker is a card game with many variants, played by two or more players. The object of the game is to win the pot, or the sum total of all bets in a deal. Each player must call, raise or fold his or her cards to do this. The rules of each game differ slightly, but in general one player places a chip into the pot for each betting interval, and all other players must either call or fold.
Unlike most games of chance, poker has a significant amount of skill and psychology when money is at stake. A player’s long-run expectation is determined by the actions he or she takes, which are chosen on the basis of probability, psychology and game theory. In addition to pure chance, the game possesses strategic elements, including learning the tells of other players and making bluffing calls.
The earliest known version of the game was played in China and Japan, but the modern poker we know and love today was developed in America. The first American developments included the use of a full 52-card English deck, and the game spread rapidly during the Civil War. Other important changes were the introduction of draw poker, stud poker and the flush (which contains 5 cards of consecutive rank, but from more than one suit). During this time the game also began to evolve into high-stakes tournament play.