Poker is a card game in which players place bets and reveal their cards at the end of the betting round. The player with the best hand wins the pot. There are many different poker variants, but the rules of the game are similar across all of them.
In a game of poker, each player is dealt five cards and must make the best hand using only those cards. The value of a poker hand is determined by its mathematical frequency, which is an inverse function of the number of cards in the hand. For example, a pair of two cards of the same rank is worth more than three unmatched cards. A flush is five consecutive cards of the same suit. A straight is five cards of consecutive ranks but from more than one suit. A full house is three matching cards of one rank plus two matching cards of another rank.
A dealer is a person who shuffles the cards, deals them to the players, and collects and tallies the bets made by the players. The dealer is also responsible for establishing certain bet sizes, depending on the game. In some games, a non-player may be given the role of dealer for an entire game. In others, a player takes the role of dealer each round.
During each round, a player may choose to call (match) the bet of the player to his left or raise it. A player who raises puts into the pot at least as many chips as the player to his left. If a player is unwilling to put into the pot at least as many chips as any preceding player, he must drop out of the betting round.