What type of literary device involves saying the opposite of what you expect?

The concept of saying the opposite of what you expect is known as irony. This literary device highlights contrasts between expectations and reality, creating a situation where outcomes differ significantly from what might have been anticipated. For instance, if a fire station burns down, it is ironic because one would not expect a place dedicated to fire safety to catch fire. Irony can manifest in various forms, such as verbal irony, where a speaker says one thing but means another, and situational irony, where actions have an effect that is opposite from what was intended.

Metaphor and simile are figures of speech used for comparison, whereas alliteration focuses on the repetition of initial consonant sounds in nearby words. These literary devices do not convey the element of contradiction that is characteristic of irony. Thus, irony is the correct answer as it specifically addresses the concept of unexpected or opposite outcomes.