Poker is a card game that involves betting between two or more players and uses probability, psychology, and game theory. The object is to win the pot (the aggregate bets placed during a hand). While Poker has significant elements of chance, the long-run expectations of players are determined by actions chosen on the basis of probability, psychology, and game theory.

There are many different variations of Poker, but most involve a standard 52-card pack with the addition of one or more jokers (these are considered wild cards and count as the fifth suit in a flush, a straight, or certain other poker hands). In some games, players use chips which represent values. Typically, the dealer assigns these values prior to the start of the game and exchanges cash from players for them.

The rules of each variant require players to put an initial contribution into the pot, called an ante. This money is not used to place bets on their hands but is rather “forced” into the pot because a player either believes that the bet has positive expected value or wants to bluff other players for various strategic reasons.

After the ante is placed, the dealer shuffles the deck and then deals each player a number of cards, depending on the game being played. Once the deal is complete the first of what may be several betting rounds begins. In some games, the dealer puts a third card face-up on the board that any player can use; this is known as the flop.