Chekhov's gun is a dramatic principle which requires every element in a narrative to be necessary and irreplaceable, and for everything else to be removed. Stated by Anton Chekhov, "Remove everything that has no relevance to the story. If you say in the first chapter that there is a rifle hanging on the wall, in the second or third chapter it absolutely must go off. If it's not going to be fired, it shouldn't be hanging there."

Under this principle, a seemingly unimportant object ("Chekhov's gun") that is shown or mentioned in the narrative will serve as a plot device or have some other significance later (i.e. foreshadowing).

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