Blind Man's Bluff is a children's game played in an spacious enclosed area, such as a large room, in which one player, designated as It, is either blindfolded or closes his or her eyes. The It player gropes around blindly and attempts to touch the other players without being able to see them, while the other players scatter and try to avoid and hide from the It player. The game is a variant of tag.

There are several versions of the game:

• In one version, the first player tagged by It then becomes It, and another round of the game is played.
• In another version, whenever any player is tagged by It, that player is out of the game. The game proceeds until all players are out of the game, at which point another round of the game starts, with either the first player or the last player to be tagged becoming the next It player.
• In yet another version, It feels the face of the person tagged and attempts to identify the person, and only if the person is correctly identified does the person become It.

A children's game similar to Blind Man's Bluff is Marco Polo.

Blind Man's Bluff should be played in an area free of dangerous obstructions so that the It player will not suffer injury from tripping over or hitting something. The game was played at least as far back as the Victorian era when it was a popular parlor game.

Blind Man's Bluff: The Untold Story of American Submarine Espionage by Sherry Sontag, Christopher Drew, and Annette Lawrence Drew, is a nonfiction book about U.S. Navy submarine operations during the Cold War.