Poker is a card game that involves chance, skill and psychology, with players betting money or chips on the outcome of cards randomly distributed to them. It has been adapted to many different settings and is widely played in casinos, home games and over the Internet. It is considered the national card game of the United States and its play, jargon and culture permeate American society.

The earliest known poker game dates to a 16th century Spanish game called Primero, which involved distributing hidden information and deceiving opponents through betting techniques. Unlike some games of complete information, such as chess, poker has resisted the encroachment of technology for much longer than other card and table-games, partly because there are so many moving parts, both in terms of the number of cards dealt and the fact that the order in which players must act changes on every deal.

Expert poker players have become adept at extracting signal from noise in complex, multichannel environments and integrating information across channels both to exploit their opponents and protect themselves. They use software to build behavioral dossiers of their opponents and may even buy or collect records of other players’ “hand histories” to increase their advantage.

When the chips are on the line, however, poker becomes a lot more like real life. The stakes are high and the decision to call or fold is an investment in an uncertain future. In addition, the betting phase is not over until all players reveal their cards in a showdown.