Chekhov's Gun

Chechov's Gun is a principal in literature and writing that states that if an element is introduced to a story then it must be used or else the audience, or reader, will feel cheated or become disapointed in the story, feeling that they were lied to, because they built up some expectations around the element.

This rule gets its name from some letters Anton Chekhov wrote to Aleksandr Semenovich Lazarev critiquing a play of his. In one letter he told a Aleksandr to remove everything from the scenery that is not relevant to the story. In the letter, Chekhov told Aleksandr that the gun he has hanginging over the door makes a false promise to the audience. The audience, Chekhov said, will assume there is a reason for its being there and it will be used to develop the story in some way.

Chekhov finished by saying that "You should not introduce an element to a story unless it is going to help resolve or move the plot forward. If you start a play with a Gun on a table, then it must be fired before the end of the first act."