:: COMPARE ::
The short answer
Exact inverses. Chekhov's gun fires what was planted; deus ex machina fires what was never planted. One rewards the attentive reader; the other tells them their attention was wasted.
Side by side
| Aspect | Deus ex machina | Chekhov's gun |
|---|---|---|
| Setup | None | Required |
| Arrives from | Outside the plot | Inside it |
| Reader feels | Cheated | Rewarded |
| Aristotle's view | Forbidden | — |
What each one means
An improbable outside force nobody set up, which turns up and resolves a plot's difficulties — usually at the end. Originally literal: a god lowered onto the Greek stage by a crane to sort the story out.
Full definition of Deus Ex Machina →Chekhov's gun is the rule that nothing conspicuous should sit in a story unless it's going to matter. Chekhov stated it as a rule about removal — if the rifle won't fire, take it off the wall — and in current usage it also names the planted detail itself: the object that turns out to matter.
Full definition of Chekhov's Gun →