Checking in the dark in poker refers to a player checking before the next card is dealt, without knowing what that card will be. Players may choose to check in the dark to add an element of surprise to their play or to create uncertainty for their opponents.
Blind man's bluff (also called Indian poker, squaw poker, Oklahoma forehead, and Indian head) is a version of poker that is unconventional in that each person sees the cards of all players except their own.