Story structure
Tragedy
The drama genre built on human suffering and terrible events befalling a main character, aiming at pity, fear and catharsis.
Tragedy is "a genre of drama based on human suffering" that comes "by way of terrible or sorrowful events that befall a main character," and its aim is to invoke catharsis in the audience. The word is the Ancient Greek tragōidia, "goat song." Aristotle's Poetics (c. 335 BCE) defines it as "an imitation of an action that is admirable, complete... and possesses magnitude" that works "through pity and fear the purification of such emotions," and it supplies the machinery the genre still runs on: the hero's error or flaw (hamartia), the reversal of fortune it sets off (peripeteia), the recognition that often fires it (anagnorisis), and the release at the fall.
Sophocles' Oedipus Rex is Aristotle's type case. The form later widened to ordinary protagonists, as Arthur Miller argued in "Tragedy and the Common Man," and to novels and film. The machinery travels: the flaw drives the fall, and the release must land, which is the craft inside hamartia and catharsis.