Poker is a card game in which players wager money, called chips, on the outcome of a hand. The game can be played with two to 14 players and has a wide range of variants. The object is to win the pot, or the aggregate amount of bets placed in a single deal. Players place bets based on their beliefs of the probability of a particular hand or to bluff other players into folding a superior hand. The game has a significant element of chance, but long-run expectations are determined by decisions chosen on the basis of probability and psychology.

During the 19th century, poker spread across America. During this time, the full English deck was introduced, and additional rules were developed, such as the flush. By the early 20th century, a number of other variations had appeared, including draw poker and stud poker.

The game can be played with any number of cards, though 2–14 is most common. A dealer, designated by the rules of a specific variant, deals the cards, one at a time face up until a jack is found. The turn to bet and the right to cut the cards passes clockwise from player to player after each deal.

Playing safe in poker can result in a lower average winnings than aggressive play. However, this style can be exploited by opponents by making them think you are bluffing more often. Trying to achieve safety can also mean missing out on great opportunities where a moderate risk could yield a high reward.