Three on a match

Three on a match (also known as third on a match or unlucky third light) is a purported superstition among soldiers during the Crimean War to World War II. The superstition holds that if three soldiers light their cigarettes from the same match, the third person, or one of the three, will be shot. The belief subsequently broadened into a general taboo against three people sharing a single match, and has been referenced in Western popular culture, including films, novels, and other media.