In scriptwriting, a reversal is a peripeteia: a serious second act obstacle to a protagonist’s objective. It refers to a reversal of circumstances or turning point. The term is primarily used with reference to works of literature.
Aristotle, in his Poetics, defines peripeteia as "a change by which the action veers round to its opposite, subject always to our rule of probability or necessity." According to Aristotle, peripeteia, along with discovery, is the most effective when it comes to drama, particularly in a tragedy. He wrote that "The finest form of Discovery is one attended by Peripeteia, like that which goes with the Discovery in Oedipus...".
Aristotle says that peripeteia is the most powerful part of a plot in a tragedy along with discovery. A peripety is the change of the kind described from one state of things within the play to its opposite, and that too in the way we are saying, in the probable or necessary sequence of events. There is often no element like Peripeteia; it can bring forth or result in terror, mercy, or in comedies, it can bring a smile or it can bring forth tears (Rizo).
This is the best way to spark and maintain attention throughout the various form and genres of drama "Tragedy imitates good actions and, thereby, measures and depicts the well-being of its protagonist. But in his formal definition, as well as throughout the Poetics, Aristotle emphasizes that" ... The tragedy is an imitation not only of a complete action but also of events inspiring fear or pity" (1452a 1); in fact, at one point Aristotle isolates the imitation of "actions that excite pity and fear" as "the distinctive mark of tragic imitation" (1452b 30).
Pity and fear are effected through reversal and recognition; and these "most powerful elements of emotional interest in Tragedy-Peripeteia or Reversal of the Situation, and recognition scenes-are parts of the plot (1450a 32). has the shift of the tragic protagonist's fortune from good to bad, which is essential to the plot of a tragedy. It is often an ironic twist. Good uses of Peripeteia are those that especially are parts of a complex plot so that they are defined by their changes of fortune being accompanied by reversal, recognition, or both" (Smithson).
Peripeteia includes changes of character, but also more external changes. A character who becomes rich and famous from poverty and obscurity has undergone peripeteia, even if his character remains the same.
When a character learns something he had been previously ignorant of, this is normally distinguished from peripeteia as anagnorisis or discovery, a distinction derived from Aristotle's work.
Aristotle considered anagnorisis, leading to peripeteia, the mark of a superior tragedy. Two such plays are Oedipus Rex, where the oracle's information that Oedipus had killed his father and married his mother brought about his mother's death and his own blindness and exile, and Iphigenia in Tauris, where Iphigenia realizes that the strangers she is to sacrifice are her brother and his friend, resulting in all three of them escaping Tauris. These plots he considered complex and superior to simple plots without anagnorisis or peripeteia, such as when Medea resolves to kill her children, knowing they are her children, and does so. Aristotle identified Oedipus Rex as the principal work demonstrating peripety.