We all know that in order for the readers to want to finish our book, we need to create a compelling story. A major part of that is coming up with an engaging and fleshed out protagonist that they would want to spend time with. So as writers, we spend a lot of time creating a backstory for your main character. And since a protagonist needs a good antagonist to create conflict and drive the plot forward, we tend to spend just as much (if not more) time fleshing out our villain as well.
But I have noticed a tendency in the last few books I read which made me go back and look over my own stories with a critical eye. See those books I read were good. The protagonist was likable, the story interesting and fast paced, the villain sufficiently evil, but not insane enough to totally put you off, but something was lacking still. Then I realized what it was – those two were the only fully fleshed out characters in the whole story. The rest of the people the hero met on his journey or who traveled with him were just talking heads with no personality whatsoever. They were just there to toss a few lines of dialogue and help the protagonist along the way. Other than that, they were non-entities. And you know what? That made for a boring read.
Human beings are social animals. We can’t exist in social vacuum. Well, neither can our protagonists. They have a family, they have friends, they have co-workers, acquaintances, people they like, people they don’t like. Heck, even if they were raised in the jungle by a pack of wolves, there would still be certain wolves they would consider friends and others they would consider enemies.
I think the mistake we tend to make when we are planning out our stories is not focusing enough on those secondary characters. We spend so much effort on the backstories of our protagonists and antagonists that we tend to forget about the rest. We feel content to just put labels on them, like the best friend, the love interest, the slightly annoying but useful sidekick. What we forget is that in order to be interesting and to add depth to the story and the world-building, those secondary characters need to have lives of their own, independently of what our protagonist is doing. The best friend doesn’t cease to exist once he leaves the protagonist’s side. The love interest doesn’t just go into her room and stare at the wall for the rest of the day once the hero is off to save the world.
What I am trying to say is that the books that I read and absolutely loved had one thing in common – fleshed-out secondary characters. Sure, they were there to help the protagonist and drive the story forward, but I could feel like they had stories of their own as well. They had their own concerns and goals. They were living, breathing people, not cardboard cutouts. And you know what? It made the books more engaging, because I really cared about what happened not only to the main character, but also to all those other people as well. Heck, I wouldn’t mind reading a standalone book about some of them.
A few examples of good books with a plethora of secondary characters are Three parts Dead by Max Gladstone. Leviathan Wakes by James S. A. Corey (and the rest of the Expanse series), or all of the Malazan Books of the Fallen by Steven Erikson (starting with The Gardens of the Moon).
I think a good indicator of whether a book has good secondary characters is to see how much fanfiction is written about them. Because if readers empathize with your characters, they will want to know more about them, thus they will create their own stories for them. Just look at the hundreds of stories written about secondary characters from the Harry Potter books.
I know it’s a lot of work to plan out and write backstories for often a large number of characters, but the reward for it is well worth it, in my opinion. First of all, your world will feel more “lived in” if people inhabiting it are tridimensional. Secondly, it gives your protagonist more inner depth if he or she has to interact with people who have their own opinions and are not afraid to disagree with him / her. And finally, you never know when you might fall in love with one of the “sidekicks” you created and make him the hero of your next story.