Idiot Plot/Theatre

Examples of Idiot Plots in Theatre include:

Phantom of the Opera, when looked at closely, proves to have a rather idiot plot. Why does Christine, after finding out that the Phantom is not the Angel of Music, fall for it again? Why doesn't Raoul just kill the Phantom when they're in the graveyard? Why don't the owners of the opera house ever investigate this "ghost" to whom they have been paying 20,000 francs per month?
Shakespeare's The Comedy of Errors. Antipholus of Syracuse has been looking for his long-lost twin brother, and comes to a town where everyone seems to know him, including someone claiming to be his wife. Somehow, neither he nor anyone else manages to come to the obvious conclusion that this is where his twin has been living.
Same with Plautus's The Menaechmi, upon which The Comedy of Errors is based.
Romeo and Juliet. The whole tragedy could've been averted had the eponymous characters (and others) bothered to think rationally for a few moments rather than emotionally. Which was arguably the point of the play.
Pretty much any of Shakespeare's plays fit this arguably, although like mentioned above, that can be the point of the play. For example, in Othello, Desdemona probably wouldn't have died if Othello had just flat-out asked her "Were you having an affair with Cassio?" or waiting to point fingers until after Iago brings the "occular proof" that he had asked for. (Assuming Othello would have believed Desdemona.)
In 13, everyone seems to be holding the Idiot Ball because they believed Lucy during "it can't be true".
In Clare Boothe's preface to her play The Women, she notes that if Mary, the principal character of her play, were a reasonably intelligent woman, she would quickly have found a different play to be in.
The opera la Sonnambula, by Bellini. Sure, she's in a compromising position... but it's completely out of character for her.

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