Problem marriages
Measure for Measure is considered a "problem play," along with Troilus and Cressida and All's Well That Ends Well. Though structured like the comedies (and often grouped with them), the problem plays are darker and more cynical. Love and marriage do not go hand in hand in Measure for Measure, nor do sexual involvement and love. Most notorious in the plot of the play is the "bed-trick" where Mariana is substituted for Isabella in Angelo's bed.
Though most of the comedies end with jubilation and marriage (with the notable exception of Love's Labours Lost), the betrothals that end Measure for Measure seem less than natural. Angelo is forced to marry the wronged Mariana, and Lucio is sentenced to marry the prostitute who is carrying his child. Most troubling of all, the Duke proposes to marry the would-be nun, Isabella, whose lack of response leaves the question of her acceptance open to interpretation.