Poker is a card game with a variety of rules and variations. It became popular in the early 21st century as the Internet made it easier to play and broadcasts of major poker tournaments brought in large audiences. It is a card game with some elements of chance but the majority of the decision-making is based on probability, psychology, and game theory. The objective of the game is to make the best five-card hand. Players place bets into the pot, which is shared by all players with a winning hand. Each player must either call, raise, or fold. The betting rounds occur in a clockwise order. In some situations a player may choose to put in all of his or her remaining chips into the pot, this is called going all-in.
Poker can be played with one or two packs of cards, the most common being a standard 52-card deck with one or two jokers. The dealer shuffles the cards and deals each player a number of cards. The first betting round begins.
After the first betting round, the cards are revealed to all players and the hand is decided. The highest hand wins the pot. A high hand is a pair or three distinct cards of the same rank, or a four of a kind (four Aces beat five Kings, for example). Ties are broken by the high card. If no one has a pair or higher, then the highest unmatched card breaks the tie (for instance, A3244 is an Ace-high hand). A high card can also break ties in a straight.