The king of hearts has five sons

The king of hearts has five sons is a little-known but traditional American deduction card game, played with a twenty-two-card subset of a standard deck consisting of the twelve court cards, four each of jacks, queens and kings, together with the ten heart cards running from ace through ten. It is best played with four or five participants and works by having two of these cards, one court card and one numbered heart card, set face down and hidden from every player at the start of a round. Through a structured sequence of questions and the logical deduction those answers allow, the players work to identify which two specific cards are the hidden pair. Game historian Bruno Faidutti has noted that the game's structure closely resembles the 1943 board game Cluedo, and has suggested, based on an account from an American who reported playing the card game at school before the Second World War, that this card game may actually predate Cluedo's own deduction mechanic.