Poker is a card game in which players bet on the outcome of a hand. It is a game of chance, but also involves skill and psychology. It can be played casually for pennies or matchsticks, or professionally for thousands of dollars. There are many different variants of the game, and it is played in casinos, private homes, and other places.

There are several rules that govern the game of official poker. The most important are that no player may act out of turn, and that each player must declare their action before doing so. If a player acts out of turn, they must pay the amount wagered by the other players in that round. Additionally, a player cannot reveal their cards until all bets have been made.

While various games of poker can be played with different numbers of cards, the standard 52-card pack is used for most games. The cards are shuffled before each deal, and two packs are sometimes used to speed up play. After each deal, the previous dealer assembles all the cards he dealt, shuffles them again and prepares them for the next dealer.

Some poker variations involve a single deck, and others use multiple packs containing the standard 52-cards plus a few jokers. Some use a special card to indicate the dealer, and some have a button (also known as the buck) which is rotated among the players to determine who deals the cards for each hand.