What is a character foil? As defined by Wikipedia: In fiction, a foil is a character who contrasts with another character, usually the protagonist, to highlight qualities of the other character.

Foils are crucial to writing fiction. They can bring out the best (and worst) qualities of the protagonist, and are often the go-to tool for best-selling writers to highlight character details and quirks.

Even Wikipedia uses the example of Harry Potter and Draco Malfoy. They are opposites in many regards, and by writing Draco into the story, it brings attention to Harry’s noble and kind nature, which otherwise might not have been tested so early in the novel.

So, when and how do you write a foil into your own work of fiction?

The short answer: you should write in as many foils as you possibly can. Why? Foils are the opposite of what they’re contrasting with, which prevents overlap in character traits (which is rather boring – if everyone had the same quiet and kind nature of Harry Potter, the novels would’ve been a dumpster fire).

It also allows for your protagonist to interact with many differing view points. Good guys, bad guys, everyone in the middle—the whole story will be made more interesting by including these individuals. Additionally, they can all offer the protagonist advice, which then leads to the protagonist making interesting (and sometimes profound) decisions.

I’m going to use everyone’s favorite superhero to illustrate my lessons. BATMAN.

Every other character is basically Batman’s foil, and it works extremely well.

Robin is typically more boisterous and energetic. He highlights Batman’s quiet and thoughtful nature.

And think about it! It’s hard to write a character alone in a scene when he’s just a quiet and pensive individual. By having someone who is more “loud” you allow the scene to retain energy (Robin commenting on everything), while allowing your protagonist to stare at the Joker’s fingerprint with a heavy scowl for hours on end.

Joker is typically evil and chaotic, with little regard for human life. He highlights Batman’s just and heroic nature.

Villain foils are some of the best, because the worse they are, the more epic the hero can become (if they defeat them). Now, some might say, “but the best villains are the ones similar to the hero!” and I would somewhat disagree. Perhaps some “same type” villains can be entertaining, but nothing bests the foil villains.

Scar from the Lion King was Mufasa’s exact opposite, and he made for a compelling villain.

Darth Vader from Star Wars was a crony for the emperor, broken by a lust for power. Luke was the ever-hopeful, and while he flirted with the dark side, he ultimately rejected everything it was, the exact opposite of his father.

Even minor characters can be fantastic foils. Going back to Batman…

Alfred is typically shown as reserved and wise. He highlights Batman’s desperation and frantic side when he stays up all night in the bat cave trying to solve that one last clue.

If Alfred was also a frantic lunatic, the scene would become clustered and lose focus. A protagonist that has to share the qualities of another risks being compared to them, and since a protagonist is the main character for a reason, you don’t want them out-shined by every other character.

So, that’s the basic lesson.

Write characters who have qualities opposite your protagonist. It helps the protagonist stand out, it prevents overlaps in character traits, and it can make the villains extra memorable and influential.