shell game

The shell game, a swindling trick in which a small ball or pea is quickly shifted from under one to another of three walnut shells or cups to fool the spectator guessing its location, is a version of one of the oldest and most widespread forms of sleight of hand. Conjurers have performed this trick, which is also called the cups and balls trick and thimblerig, throughout the world for centuries. The version that became popular in the United States in the late 19th century used walnut shells and peas. Shell game thus became the popular term for the trick, and the trick itself became so well known that the term is now used figuratively to describe dishonest actions that are done to deceive people.