Official poker is a card game in which players compete for an amount of money or chips contributed by the others (called the pot). Usually, individuals are required to place a small number of low-denomination chips into the pot at the beginning of each betting interval. These chips, which are known as the ante, increase the pot size and help players to predict what cards other players may have. In some games, especially tournaments, each player is required to contribute a minimum amount of money into the pot. Similarly, the players may establish a special fund, called a kitty, into which the pot funds are placed. Any chips left in the kitty at the end of the poker game are divided equally among the remaining players.
Most poker games are based on a standard pack of 52 cards, sometimes with one or two jokers added. Generally, the cards are ranked in order from high to low: Ace, King, Queen, Jack, 10, 9, 7, 6, 5, 4, 3 and 2. Each poker game also has specific rules for ranking the card combinations, such as four of a kind or a full house. In addition, a significant element of poker is bluffing.
Other card games, such as blackjack and baccarat, have similarities to poker in that they involve betting and winning by making the best combination of cards. In addition, some video games that function as slot machines can be considered to have a form of poker because they use the same basic mechanics of betting in rounds.