Poker is a game of chance in which players compete for a pot of money, with each hand involving a series of betting intervals. Each interval ends when a player either calls or raises the previous bet.
There are two types of games: draw and stud. The game begins with each player being dealt a card face down. After this initial deal, there are three rounds of dealing. The player with the highest-ranking poker combination in his faceup cards is the first bettor; if two or more players have the same combinations, the player nearest the dealer’s left bets first.
Each round of betting is over when each player has called, checked, or folded (folded means discarding a hand and losing any chips that have put into the pot). If all players have folded before the round is complete, a showdown takes place in which the hands are revealed.
Players may discard up to three cards from their hands, taking new ones from the deck. Depending on the rules of the variant, this can be done during or just after the betting phase.
Some variants of the game allow a player to check, which means that the player stays in the game without making any bet, provided no one else has made a bet during the betting interval. The player must still call a bet that has been raised by another player, though.
Some variants of the game have a limit on the number of raises that may be made in any betting interval. These limits vary with the specific poker variant, but they are usually based on probability and psychology, which allow the long-run expectations of players to be determined.