Players take on the role of suspects and attempt to solve a murder. The solution to the murder contains the three components of Suspect, Weapon and Room.
The game contains:
The gameplay involves moving the game pieces around a board depicting the interior of a country house (supposedly the residence of the deceased) and the cards. Dr. Black is the name of the deceased person (Mr. Boddy in North American version). This game is unusual in that it requires at least three players, as opposed to a minimum of two for most board games.
The suspects are called:
At the beginning of play, one card of each type is chosen at random and put into a special envelope to represent the true facts of the case. The remainder of the cards are distributed among the players.
The aim is to deduce the details of the murder. This is done by announcing suggestions to other players. A typical suggestion would be, for example, "I suggest it was Mrs. White, in the Library, with the Rope." All elements contained in the suggestion are moved into the room in the suggestion (so Mrs. White and the Rope would be moved to the Library). The other players must then disprove the suggestion if they can. This is done in clockwise order around the board. A suggestion is disproved by showing a card containing one of the suggestion components to the player making the suggestion (for example, the Rope). Showing the card to the suggesting player is done in secret so the other players may not see the card being used to disprove the suggestion. Once a suggestion has been disproved, the player's turn ends and moves onto the next player. The player's suggestion only gets disproved once. So, though several players may hold cards disproving the suggestion, only the first one will show the suggesting player his or her card. A player may only make a suggestion when his or her piece is in a room and the suggestion can only be for that room.
Once a player thinks he or she knows the solution, the player can make an accusation. The player checks the validaty of the accusation by checking the cards in the file. If the player made an incorrect accusation, that player is out of the game (since the player now knows the correct solution). If the player made a correct accusation, the solution cards are shown to the other players and the game ends.
An interesting feature of Cluedo's design is that it is possible for a player to be using the piece representing the murderer. This doesn't affect the gameplay, the object of the game is still to be the first to make the correct accusation.
In North America, the game is known as Clue. Possibly it was retitled because the traditional game Ludo, on which the name is based, was less well known there. There are also localised versions for Japan and China.
There was a US comedy film based on the game, as well as several interactive video versions. In the US film version, the person murdered was Mr. Body.