Clue Card
A card providing a constraint about suspect positions, relationships, or identities.
Explanation
Clue cards are the information source in Murdoku. Each card describes a constraint: a suspect's position relative to an object, a relationship between suspects, or information about the victim/murderer. All cards must be satisfied simultaneously.
Example
'The person beside the bookshelf is not the murderer' is a clue card that restricts the murderer's position relative to the bookshelf.