You have friends, and so should your characters.
Main characters shouldn’t hold the entire story. They need help, and that help comes in the form of supporting characters. These are the people your main characters meet who leave an impression. I’m not talking about that shopkeeper your protagonist spoke with briefly who was nothing but filler material to end the scene.
Readers should remember supporting characters. Give readers someone to love, hate, laugh at, cry with, etc. Oftentimes these characters will have important connections to your main characters: friends, family, mentors, bosses, girlfriends, roommates, classmates . . . you name it.
Simply put, supporting characters should influence your main characters—and the story—in a significant way.
So the question remains: “How do you create supporting characters that fit your story’s plot and help your main characters?”
Let me answer that. Here are three ways to develop supporting characters.
1. Give Supporting Characters Independent Goals
The story follows the main character, yes, but that doesn’t mean the whole world revolves around that character. Things happen. Supporting characters are likely to be involved in behind-the-scenes activities that influence society or the MC’s personal world.
Give supporting characters a life. What are they trying to accomplish? What obstacles are in their way? How do they interact with other characters, especially the main character?
Then dig deeper. What scares your supporting characters? What makes them happy? Do they try to avoid work? Do they jump at the chance to go on adventures? Do they party, or do they stay inside on Friday nights?
All these questions sound like things you would ask about your main character—and it’s true, you would. The first key to creating believable supporting characters is treating them as if they are the main character . . . but tone it down. You don’t have to show us every minute of their lives, just the parts that show us their personalities, affect the story, and influence the main character.
2. Focus on Speech Patterns of Your Supporting Characters
What do your supporting characters say? Are they so hyper that words spill out of their mouth so fast you could clock it on radar? Or are they reserved, and speak only when spoken to?
I always say dialogue is the most effective form of characterization. You can use quirks, stutters, slurs, screams, whispers, catch phrases, dark words, and light words. You can express intentions. Hide secrets. Blow secrets. Emotions flow through dialogue too.
Dialogue reveals so much about characters. A good way to create unique speech patterns is to let each of your characters say certain words a lot, or act a certain way while talking. Then your readers can identify who is speaking at any given moment, thus eliminating confusion.
3. Let Your Supporting Characters Represent Some Aspect of the Story
Supporting characters allow you to mix multiple themes and lessons into your story. One character can represent strength and another compassion. Perhaps one redeems himself after failing to assist the main character in an earlier predicament.
Use characters to their full potential. Don’t just put them in the story so your main character has someone to talk to. As I stated in the first point, give them a goal. In a similar way, when working on a theme, you can send these characters on their own journeys.
Readers will watch their strengths and weaknesses and see the choices they make. This will add layers to the story as readers become more invested in the lives of the people surrounding the main character.