A check-raise in poker is a common deceptive play in which a player checks early in a betting round, hoping someone else will open. The player who checked then raises in the same round.

In the card game of poker, to bluff is to bet or raise with an inferior hand. This is useful because it can cause other players to believe the bluffing player has a dominant hand, so that they all fold; the bluffing player then wins the pot. By extension, the terms are often used outside the context of poker to describe the acts of pretending knowledge one does not have, or making threats one cannot execute.

Pure bluff

In the game of poker, opens and raises are considered aggressive plays, while calls and checks are considered passive (though a check-raise would be considered a very aggressive play). It is said that "aggression has its own value", meaning that often aggressive plays can make money with weak hands because of bluff value. In general, opponents must respond to aggressive play by playing more loosely, which offers more opportunities to make mistakes.