As About.com explains, Clue is a murder-mystery board game in which players determine which character committed a murder, where the murder occurred and what murder implement was used. To play the game, players move playing pieces around the game board to collect clues, then make an accusation of murder when they believe they have solved the clues.
Before a game of Clue starts, the clue cards are shuffled and, without looking at them, one suspect card, one room card and one weapon card are placed in a small envelope; these cards provide the solution to the murder mystery. The rest of the cards are shuffled and dealt out to the players. Each player then chooses a suspect to play, and he places his suspect's token on the board.
The player playing Miss Scarlett always goes first, and the play moves clockwise around the board. On his turn, each player rolls a die, and he moves his token the corresponding number of places in an attempt to reach one of the rooms on the board. Players cannot move diagonally on the board.
Once in a room, a player suggests a possible scenario for the murder, naming a suspect, a room and a murder weapon. If the player to his left holds any of the cards suggested, he must reveal one of them privately. The player who made the suggestion keeps track of the information received to continue deducing the correct answer.
When a player thinks he has solved the murder, he must direct his token to a room on the board to make an accusation. After making an accusation regarding a suspect, room and murder weapon, the accusing player checks the envelope to see if his answer is right. If it is, he reveals the cards in the envelope to show that he has won the game. If not, he loses the game, and he is eliminated. The other players continue the game without him.