Poker is a card game played between two or more players and governed by a set of rules. The objective of the game is to win a pot, which is the sum total of all bets placed during one round of play. The player with the highest-ranking poker hand at the end of the betting period is declared the winner. The player can also choose to fold his cards and forfeit the pot.

There are several forms of poker, with different rules for each. The game may be played with any number of players, from 2 to 14, but optimum numbers are 6 or 7 players. In most cases a player must place an initial contribution, called the ante, before being dealt cards. Depending on the game, this can be anything from 1 to 100 chips.

During each betting interval, a player has the option to increase his or her stake in order to stay in the pot. To do this he must match the total contribution to the pot made by the last player. The player may also raise his or her stake further, or if unwilling to do either of these, must fold.

Making decisions under uncertainty is a key skill in poker, as it is in other areas like finance and business. To make an informed decision, you must estimate the probabilities of various outcomes. You can do this by analyzing the available information and comparing it against your own expectations.