Poker is a card game that can be played in many ways by people of all ages, from children to professional gamblers. It is a game of chance, but it also requires considerable skill to minimize losses with bad hands and maximize gains with good ones. It can be played socially for pennies or matchsticks, or professionally for thousands of dollars in casinos and private games rooms.

Players purchase a specified amount of chips at the beginning of a session, which is called buying in. Each player then has the opportunity to bet in each betting round. Depending on the game, a player can check, bet (called calling the bet of an opponent), raise or fold. After each round, the remaining chips are put into the pot.

The game is usually played with poker chips, which have various values. A white chip is worth a minimum ante or bet; a red chip is worth 10 whites; and a blue chip is worth 20 whites or two, four or five red chips.

Most poker games are not regulated, and each game may have its own specific rules. There are, however, a few universally accepted rules that govern the game. The most important of these rules is that the highest ranking card wins each hand. This is known as the high card rule. Other important rules include the use of wild cards, which can replace any other card in a hand to improve it, and the so-called kicker rule, which dictates which additional card counts in a pair.