Poker is a card game for two or more players, played with a standard deck of 52 cards. The object is to win the pot, which is the sum of all bets made in one deal. The pot may be won by having the highest-ranking poker hand, or by making a bet that no other player calls. Players may also bluff, with the aim of scaring away players holding inferior hands.
Depending on the poker variant, one or more players are required to place an initial amount of money into the pot before the cards are dealt, called antes, blinds, or bring-ins. This is done to ensure that each player contributes at least the same amount as the player before him. This is a fundamental aspect of the game and is an essential element of the risk-vs.-reward concept that is the basis of most decisions in poker.
There are many different forms of poker, but most share the following basic features: A poker hand consists of five cards. Each card has a rank, which is determined in inverse proportion to its mathematical frequency. There are 13 card ranks, which yield 169 possible starting hands. The higher the rank, the more valuable the hand. Players bet on the strength of their hands and attempt to win the pot by bluffing, or by calling bets from other players with superior hands. They may also check, in which case they forfeit the opportunity to see the turn or river cards.