In the Anglicized form, "peripety"; the reversal of the protagonist's fortunes that, according to Aristotle, is part of the climax of a tragedy.

When a deed or action backfires or has a reverse effect. (see also Ironic deeds or situations, SG 157).

a sudden and unexpected change of fortune or reverse of circumstances (especially in a literary work); "a peripeteia swiftly turns a routine sequence of events into a story worth telling"

In tragedy, an unexpected reversal of fortune for the tragic protagonist. Usually where the tragic figure suddenly turns from good fortune to bad fortune because an hamartia, like Oedipus’ relentless search for Laius’ killer leads him to torture Jocasta’s old servant in order to confirm what he already suspects. From here, he blinds himself, and Jocasta hangs herself based on the former's patricide and incest.

Peripeteia (Greek, ) is a reversal of circumstances, or turning point. The term is primarily used with reference to works of literature. The English form of peripeteia is Peripety.