Poker is a card game in which players compete for the highest-ranked hand of five cards. The winner of each hand wins the pot – all the chips that have been bet during that hand. The game is not just about luck, but also depends on skill and psychology. For example, knowing your opponent’s tells can help you to weigh up whether or not it is worth raising your bet.

A player may call a bet by putting into the pot the same amount as the preceding active player, raise it by adding to his own stake (also called raising), or drop his hand – discards it and leaves the betting to others – in which case he forfeits any chips that he has already put into the pot.

The rules of the game vary according to the variant being played. But the basic principle is that each active player, in turn starting with the dealer, must either call a bet or raise it. If he refuses to call, he must drop his hand.

The history of Poker is complex, and there are many different claims as to its origins. However, the first comprehensive account of the game and its variants was published in 1904 by R F Foster. It summarised the fruits of extensive research into the game, and included the results from a significant collection of card-game literature housed in the Bodleian Library at Oxford. This was followed in 1905 by the work of James Dowling, a distinguished anthropologist.