Poker is a card game in which players bet chips and win or lose them depending on the quality of their hand. It is a fast-paced game with players betting continuously until one player has all the chips or everyone folds. A variety of betting strategies can be used, including raising, calling, or folding. Unlike chess, where each move is committed before information is known, a poker hand mimics the real world in that resources must be invested before a decision is made.
A poker hand consists of five cards. The higher the rank of a hand, the more valuable it is. The cards are ranked in inverse proportion to their mathematical frequency; the more rare the hand, the higher it ranks. Poker can be played with any number of players, but the ideal number is six to eight people. Players place chips into the pot before being dealt cards, which they keep hidden from other players. A player may increase their bet at any time, and other players must call the raise or fold. Players may also bluff, betting that they have a superior hand when they do not.
The highest-ranking hand is a royal flush, consisting of a 10, jack, queen, and king of the same suit in one color (all hearts, clubs, diamonds, or spades). Other common hands include a straight, three of a kind, four of a kind, or two pair. A pair consists of two matching cards of one rank and two unmatched cards of another rank.