Hamartia [ham-ar-shee-ah, shuh]
The fault or error which entails the destruction of the tragic hero.
From a Greek word, meaning fault, failure, guilt. Unfortunately, Greek letters don't copy so well into LJ so I haven't included it here.
1789 T. Twining Aristotle's Treat. Poetry 308 Dacier confounds himself and his readers in his note about Thyestes. He mistakes Aristotle's sense of hamartia.
Tordak the Mighty was pretty pissed when he pulled his fatal hamartia out of the hat. I mean, that Achilles guy got a tendon on his foot, Samson pulled out his hair, and Harry Dresden got a coin wih a demon inside - but, really, this was a little open to abuse.. anything blue? REALLY?