Stud poker
Stud poker is any of a number of poker variants in which each player receives a mix of face-down and face-up cards dealt in multiple betting rounds. Stud games are also typically non-positional games, meaning that the player who bets first on each round may change from round to round (it is usually the player whose face-up cards make the best hand for the game being played). The cards dealt face down to each individual player are called hole cards (which gave rise to the common English expression ace in the hole, which suggests that one has something valuable that is not apparent to others).
History
Stud poker variants using 4 cards were popular as of the American Revolutionary War. Five-card stud first appeared during the American Civil War when the game was much played among soldiers on both sides, and became very popular. In recent years, Seven-card stud has become more common, both in casinos and in home games. These two games form the basis of most modern stud poker variations.