Poker is a card game with countless variants, but all involve betting. A hand consists of five cards and is valued in inverse proportion to its mathematical frequency; higher-ranked hands generally win more money than lower-ranked ones. Players may place a bet by placing chips (representing money) in the pot; other players then must either call the bet or fold. Players may also bluff by pretending to have a superior hand, which can sometimes induce others to call their bets.
Typically, each player buys in for a set number of chips. A white chip is worth one unit of the minimum ante or bet; a red chip is worth five units of whites; and a blue chip is worth 20 or 25 whites, depending on the particular game. Each player then places his or her chips into the pot during one of several betting intervals, which end when a player has put in as many chips as all those before him or has dropped.
The players who remain then show their cards and the best hand takes the pot. In some games, a pair of deuces is considered the lowest hand and must be discarded; in others, they are kept and made part of a higher-ranked hand. By mutual agreement, the players usually create a fund, known as the “kitty,” for paying for new decks of cards and other needs for the game. Unless the kitty is used up, any chips left in it when the game ends are divided evenly among the players who have continued to play.