Fair Play in Classic Mystery Stories

Classic mystery stories have a rule called fair play. It means the author should give readers an honest chance to solve the mystery on their own.

All the important clues must appear in the story and be possible to understand correctly. An author may cleverly hide them among unimportant details and false clues, but should not reveal the decisive evidence only during the final solution.

This rule became especially important in Golden Age puzzle mysteries of the 1920s and 1930s, and Agatha Christie was a master of them.