Situations where a trope involves a character of a gender different than usual, making the trope either more accepted by the audience or rationalizing why the characters don't react in the usual way. Interestingly, this is useful so fans or writers can rationalize something away that they've been taught is otherwise unfashionable to tolerate without actually changing the underlying premise. Related to Always Female / Always Male (except this time it isn't). Reversing the gender of characters in a story to explore how things might be different is in Gender Flip.