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.
A calque of the Greek 'apo mēkhanēs theos'. The Latin form is the standing name.
// Where it sits
Aristotle allowed it for matters outside the drama — never for untying the plot.
What it really means
There was an actual machine.
The mēkhanē was a crane used in Athenian theatre to fly an actor playing a god into the scene — swung out over the stage, lowered from above, arriving physically from a place no character could reach. When a plot had knotted itself beyond untying, the god came down on the crane and announced the resolution.
So deus ex machina is not a metaphor. It's a description of stage equipment, and the contempt in the phrase is contempt for a specific piece of theatrical hardware.
The criticism is also as old as the device. Around 335 BC, Aristotle wrote in the Poetics that the unravelling of a plot must arise from the plot itself, and not produced mechanically as in the Medea, in W. H. Fyfe's translation — naming Euripides' play, though not Euripides himself. Horace repeated the ban three centuries later, allowing a god from the machine only if the knot were worthy of a god. Nobody had to wait for modern criticism to notice the problem.
What Aristotle did permit is worth knowing, because it's more precise than the blanket prohibition people assume. A god could legitimately handle matters outside the drama — events before the action, or after it, which no character could know. What was forbidden was using one to untie the plot.
The test still works. Not was the ending happy? but: could this have happened at any point in the story, for no reason connected to anything that came before?
Where it comes from
The machinery is literal, not metaphorical. There was a crane.
Myths & misconceptions
Any lucky or convenient ending is a deus ex machina.
The device requires a solution arriving from OUTSIDE the established plot - a person, a thing or an event the story never set up. A prepared coincidence, however convenient, is just weak plotting — the defining feature is that the solution arrives from somewhere the story never established.
The Greeks used it uncritically until moderns noticed the problem.
Aristotle attacked it by name in the Poetics, around 335 BC, citing Euripides' Medea. The criticism is as old as the device.
Compare & contrast
Deus ex machina vs Chekhov's gun
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.
| // | Deus ex machina | Chekhov's gun |
|---|---|---|
| Setup | None | Required |
| Arrives from | Outside the plot | Inside it |
| Reader feels | Cheated | Rewarded |
| Aristotle's view | Forbidden | — |
How it connects
- EucatastropheTolkien's answer to this — the rescue the story earned rather than imported.
- Chekhovs Gunthe opposite rule, about firing only what you planted.
Tell it apart
Questions people ask
- Was there really a machine?
- Yes — the mēkhanē, a crane used in Athenian theatre to fly actors playing gods into a scene. The phrase is a literal description of stage equipment, which is why the metaphor has such a specific shape.
- Is it ever legitimate?
- Aristotle allowed the device for matters outside the drama proper — things that happen before or after the action, which a god could reasonably announce. He barred it from untying the plot itself. Horace allowed it only if the knot were worthy of a god.
- How is it pronounced?
- DAY-uhs eks MAH-kih-nuh is the usual English; DEE-us eks muh-SHEE-nuh is also entirely current and nobody will mind. Restored classical Latin would be closer to DEH-uus.