Poker is a card game with a variety of betting rules. Players place a bet, or “chips,” in the pot, and then take turns revealing their cards until one player has a winning hand. A player who wins the pot collects all of the chips that were put down as stakes. If there is a tie among the best hands, the pot is divided equally among the players.

Unlike most card games, which have only a handful of variants, Poker has dozens of different betting types, formats, events (cash games versus tournaments), and stakes. The mathematics and theory can differ dramatically between these variants.

A player may choose to stay in the pot by calling a raise, or may raise the stakes themselves. In some cases, a player can make an all-in bet, which is a single bet of the total amount of money in the pot. These bets are usually matched by the player who made the raise, or they are folded.

The earliest contemporary reference to poker comes from the 1836 publication of J. Hildreth’s Dragoon Campaigns to the Rocky Mountains, where he writes that the American ambassador to Britain, General Schenck, was prevailed upon by a party of guests to teach them this peculiarly American game of Poker. Two slightly later publications independently confirm this account, in the published reminiscences of Jonathan H. Green in Exposure of the Arts and Miseries of Gambling (1843), and Joe Cowell, an English comedian, in Thirty Years Passed Among the Players in England and America (1844). The game became popular in the United States during the early 19th century and spread westwards along the Mississippi River and across the frontier to the Great Lakes and beyond.