In literature, the term foils refers to two characters who help to develop each other by contrast. In other words, foils are characters who are so opposite from each other that they help to develop each other.
In “The Wizard of Oz,” for example, the good witch looks even better when contrasted with the bad witch, and the bad witch looks even worse when contrasted with the good witch.
Some of our favorite characters from fiction are in fact foils. Just consider how wonderfully these characters define each other by contrast:
For Prompt Six, I’d like us all to write a paragraph of at least 200 words which shows the reader two characters who are complete opposites interacting with each other. First, create a setting where two opposite characters might meet–an elevator, say, or perhaps a small waiting room in a doctor’s office.
Your prompt should be written in the third person point of view, but don’t allow your narrator to tell the reader how these two characters are foils. Allow your characters to reveal they are foils through vivid dialogue and action.
Your prompt may be funny, serious, a combination of both–whatever! But show the reader how your characters help to define each other through contrast.