Bed trick

The bed trick is a plot device in traditional literature and folklore; it involves a substitution of one partner in the sex act with a third person (in the words of Wendy Doniger, "going to bed with someone whom you mistake for someone else"). In the standard and most common form of the bed trick, a man goes to a sexual assignation with a certain woman, and without his knowledge that woman's place is taken by a substitute.

Instances of the bed trick exist in the traditional literatures of many human cultures. It can be found in the Old Testament: in Genesis Chapter 29 Laban substitutes Leah for Rachel on Jacob's wedding night, as Jacob discovers the following morning. Other examples range throughout the Western canon (several occur in Arthurian romance, as well as in Chaucer's "The Reeve's Tale") and can be paralleled by instances in non-Western cultures.

For modern readers and audiences, the bed trick is most immediately and most closely associated with English Renaissance drama, primarily due to the uses of the bed trick by Shakespeare in his two dark comedies, All's Well That Ends Well and Measure for Measure. In All's Well That Ends Well, Bertram thinks he is going to have sex with Diana, the woman he is trying to seduce; Helena, the protagonist, takes Diana's place in the darkened bedchamber, and so consummates their arranged marriage. In this case, the bed trick derives from Shakespeare's non-dramatic plot source, the ninth story of the third day in the Decameron of Boccaccio (which Shakespeare may have accessed through an English-language intermediary, the version in William Painter's Palace of Pleasure). In Measure for Measure, Angelo expects to have sex with Isabella, the heroine; but the Duke substitutes Mariana, the woman Angelo had engaged to marry but abandoned. In this case the bed trick was not present in Shakespeare's sources, but was added to the plot by the poet.

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