Welcome back. I was surprised to find that this was a question. So, I had to touch on it and explain supporting characters. Enjoy.
Do I Need Supporting Characters?
A story can be made or broken by the supporting characters who range from traveling companions to minor villains. Of course, you can have your hero go it alone and have a focus on how someone will carry on when isolated. This is more difficult than one would think because you create a supporting cast as soon as you introduce another character. It might not even be a speaking part. That troll? Supporting character even though it’s a monster. That shop owner selling cheap swords? Supporting even though he only shows up for one scene and has a few simple lines of dialogue. This is a fairly broad definition, but these are all characters who add more color and life to your story. Hence, they should not be ignored entirely.
On the other hand, you don’t have to go deep with these characters if they’re minor and closer to set pieces. Putting hours of thought into a healer who shows up and leaves on the same page is overcompensating. It’s clear they have a purpose, but not enough that the audience needs a full backstory. I would suggest that the amount of time you put into creating supporting characters really should be dependent on how much you are going to use them.
You can divide your cast into three categories to help here:
- Primary– This is your main hero and main villain. The story revolves around these characters, so they have to be the deepest. They are the most likely to change throughout the story too. Names, physical description, evolution, backstory, and focus are certainly required more than the other groups. If you are writing an ensemble story, you will have more characters in this category. Never think you can only have 2 characters as primaries if you have multiple heroes and villains who are heavily involved in the plot. That leads to favoritism and the story can be weakened by you reducing the importance of the others while they are truly critical to the events.
- Secondary– These are your mentors, independent rivals, allies, third party enemies, and other characters who are important, but not central. They influence the primaries and the story, but they are not the major motivators of the big events. When the battles and adventures hit the high gear, they are standing a few steps back and giving support. They might not be there at all. It helps to have some depth like the primaries including a backstory. Yet, they don’t need a big evolution or one at all because they are distanced enough from the story events. In other words, character development is optional and can be minimal here.
- Tertiary– I would put the store owners, key monsters, healers, nobles, and anyone else who shows up for a little time here. They don’t travel beyond their initial area because they serve a single purpose. In a series, you can eventually have them evolve to secondary if they show up more often. If not then you really only need a name, physical description, and a purpose. There’s no evolution here, especially if they’re around solely to be killed.
We are going to be focusing more on the secondary group for, what I think, are obvious reasons. Primary are too essential and tertiary are too temporary. Secondary is where you can find a lot of development catalysts for the characters, story, and world. This is because they aren’t the major movers of events, but influencers of those who will do it. I’d say the men and women behind the curtain if you didn’t see them act. Then again, some supporting characters do stay in the shadows until near the end for a big reveal. That’s a rather niche use though. Beyond the precious plot twist, you get tons of mileage from the secondary cast. I would say more than the primaries in certain areas, which is why it’s important to give these characters more attention than a passing fancy.