Poker is a card game of chance, but it also involves skill and strategy. It is believed to be an ancestor of other card games such as blackjack and rummy. In most poker games, the object is to have the best poker hand at the end of the game. In the United States, the game of poker became popular after the American Civil War. It is now played in many countries around the world.
When it is your turn to act, you must either call (match the last bet or raise) or fold your hand. Some players may choose to bluff during a hand for various reasons. For example, a player with a strong hand might try to force weaker hands out of the game or increase the value of their winnings. These bluffs are made on the basis of expected value, psychology, and game theory.
A strong poker hand must consist of at least three cards of the same rank and two unmatched cards. Four of a kind is four cards of the same rank, and a flush is five cards that are consecutive in rank and of the same suit. A full house is three matching cards of one rank and two matching cards of another rank, and a straight is five cards in sequence but from different suits.
The highest ranking poker hand wins the pot, although there are some games where the lowest hand wins. In some games, the high and low hands split the pot, known as a high-low split.