“And the award for Best Supporting Actor goes to ….” We need our leading man and lady, but where would Scarlett O’Hara be without Mammy? (Hattie McDaniel won the Oscar that year). Without Mammy to lay down the law, Scarlett would have nothing to rebel against, so how would we get to know her feisty side? Luke Skywalker needs Han Solo for contrast and conflict.
Romance is a genre built on characters. Boy meets girl (usually) and the story revolves around their relationship, but we need family, friends, enemies, and even strangers for them to play off if we want to get to know their true personalities. There’s a reason superheroes have sidekicks.
The best friend who encourages the heroine to take a chance is a staple, but sometimes the friend instead urges caution and the heroine must convince her or even defy her. Either way, we get conflict and contrast, a sounding board. Perhaps our heroine must stand up to a controlling mother, or make up for a distant one, and that shapes her personality. Even the most minor characters can be important. If a man is rude to the pizza delivery boy, we’ve learned something about his personality.
Characters don’t have to be people. In many books, the setting almost becomes a character. A sudden flood can trap the main characters together, acting as the antagonist. In
one of the most endearing characters is Lindy, a cocker spaniel. She’s no
Lassie, but she’s an outstanding love-sponge, and Ben’s patience and affection
are revealed through his relationship with Marsha’s little dog. Another
character in the story isn’t even alive. Marsha’s late husband clearly influences her
thoughts and actions through her memories of him.
As a reader, I want to get to know the main characters, to feel what they feel and root for their success. I want to live inside the story for a little while. Well-developed supporting characters play a huge role in making that happen.