Poker is a card game in which players wager chips (representing money) on the probability that they have a winning hand, or pot. It is often played in private homes, clubs and casinos, and it has been a significant part of the growth of gambling throughout the world. In the United States, poker is the national card game and its rules and jargon are widely regarded as part of American culture.

Before the cards are dealt, players must place forced bets, called the ante and blind bets. These bets are made before the player is allowed to check (checking means that the player does not want to call the previous bet) or raise his or her stakes. The player may also fold.

After the antes and blinds are placed, players are dealt cards in rotation. Depending on the variant being played, these cards are either face-up or face-down. Each player then places his or her bets in the pot, and after a series of betting rounds, each player reveals his or her cards. The player with the highest hand wins the pot.

In addition to providing a social outlet, poker offers a wealth of insights into game theory and decision making. It has become a subject of intense research in areas as diverse as computer science, psychology and mathematics. In particular, it provides insights into the process of “equalization”—a method by which a player wishing to stay in a pot must equalize his or her contribution to that of the last raiser and, if unwilling to do so, must fold.