How to write supporting characters in fiction

Guest author and blogger William Ryan is author of the Captain Korolev Novels, shortlisted for numerous awards, including the Theakstons Crime Novel of the Year, The Kerry Group Irish Fiction Award, the Ellis Peters and John Creasey Daggers and the Irish Crime Novel of the Year (twice).

He teaches on the Crime Writing Masters at City University in London and shared with us this excerpt, expanded and adapted, from the book he co-wrote with M.R. Hall, Writing Crime Fiction, on writing great supporting characters. Whatever your genre, enjoy these words of wisdom.

When you’re writing a mystery novel, or any novel for that matter, you need a protagonist who works for the novel. That means, in my view anyway, that they have to be intriguing enough that the reader wants to spend time in their company, that they are the character whose eyes this story must be told through and that they are the character who makes all the key decisions that take the story from the beginning to the end. Let’s presume you have just such a character, filled with multiple layers and tempting internal contradictions. Now you need to populate the rest of the novel. So you need some subsidiary characters.

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Subsidiary characters don’t have the same functions as the detective in a mystery novel – they don’t drive the story in the way that the central character does, although they may be key to how it progresses. In general, they exist for one of the following four purposes:

  • To be the victim of a crime, either directly or indirectly.
  • To prevent or obstruct the detective from solving a crime.
  • To assist the detective in solving a crime.
  • To tell us something about the detective or the setting.

For example, a child may set out to mislead a detective by lying to them but actually end up assisting their investigation by inadvertently revealing a key piece of information. This unintentional assistance might result in the child’s murder, making them a victim, and the discovery of their body may reveal a more sensitive side to the detective’s personality that hasn’t been apparent until then. That character is earning their place on the page. There are always exceptions, of course, but if a secondary character doesn’t fulfil at least one of the four roles outlined above, you probably need to reconsider their inclusion. You may still have a valid reason for keeping them, but it’s probably a good idea to work out what it is. If the reason you come up with isn’t related to pushing the story forward then you may well want to kill them off. It’s seldom the case that a character gets a free ride in a good crime novel – they have to work for you, and for the central character, or they have to go.

Aside from asking what their role in the novel is, it’s always a good initial question to ask of each of your secondary characters: ‘who do you appear to be, and who are you underneath?’ By hiding something about a character at the outset, you will, almost effortlessly, make them interesting and potentially surprising. Also, because you know that you’ll have to reveal the truth about them later on, you’ll begin to foreshadow that truth and, because you’re going to be straight with your reader, except when you’re misleading them, you’ll be circumspect about confirming the appearance the character maintains at the outset – and the reader will pick up on that.

You will also need to understand why each of your subsidiary characters behaves the way they do in the novel. Even an insane serial killer will generally have a reason for their murder spree – no matter how bizarre it might be – and discovering the reason why a murder has been committed is often to discover the killer. Not every character in the novel is a murderer but that doesn’t mean their motivation shouldn’t be explored. If the detective’s spouse leaves them half way through the book then your readers will want to know why. Likewise the senior officer to whom a police detective reports may well have valid reasons for interfering in their investigation and trying to rein them in, and it will help if you, and the reader, understand their concerns.

Often the motivation for the subsidiary character’s behaviour will have something to do with the central character. Conflict is, after all, going to help drive your plot forward. In Ian Rankin’s The Black Book, Rebus is in conflict, of one sort or another, with every one of the major subsidiary characters, and most of the minor ones as well. The more conflicts you can establish, the more challenges and obstacles your detective is likely to have to overcome. Sometimes the conflicts may be subtle – your detective may be attracted to another character that may, at least initially, not feel the same way about them. This relationship may be only a sub-plot in the novel, but it might tell the reader something of the detective’s character and, hopefully, make the reader warm to him or her. All of the central character’s conflicts with other characters will have a trajectory over the course of the novel and will, generally, be resolved by its end even if, with a series, only in an uneasy truce until the confrontation resumes in the next book.

As with the central character, you are going to have to name your subsidiary characters, decide what they look like, where they’ve come from and fill in the details of their personality. With the more minor characters, you may not have to do this – a taxi driver who follows a suspect at the detective’s request isn’t going to have enough time allocated to them in the novel to allow for much more than the briefest of sketches. However, that said, the more time you spend thinking about a character, even if they only make the briefest of appearances, the more vivid they’ll be on the page. It’s a bit like the research you’re going to do for your novel – much of your work won’t make it onto the page. Instead it forms a hidden structure that gives the novel its authenticity. The reader believes in the world you’ve recreated for them, because you’ve done the research and speak with authority on everything you describe. It’s the same with characters – because you know all of this information about them, they acquire a depth on the page.

Although there are no absolute rules about the number of secondary characters in a crime mystery, remember that the reader will struggle to get to know more than a dozen with any degree of intimacy (you can discount minor characters who appear for less than a page in coming to this number). Obviously each novel is different and some, by their very nature, will be more heavily populated than others but it’s generally a good idea to be wary of extended casts, especially when their role in the story might be easily combined into another character’s.

This brief overview of how to write subsidiary characters has been set in the context of crime fiction, specifically the mystery novel, but it equally applies to most other genres and most literary fiction. If you think of the solution of the crime as being the objective of the detective, then the points discussed above relate to any novel where the protagonist has to overcome challenges, whether external or internal, and conflicts to achieve their objective. For example, romantic fiction tends to work exactly the same way – the lover’s objective, which they may not necessarily be aware of, is to find love in the arms of another character. Most of the other characters are going to either be rivals for the affection of one of the two characters, or exist to provide conflict, assistance or obstruction in relation to the final goal, or be in the novel to give insights into the character of the lover or the loved one.

You can certainly include other characters, perhaps for humour or even tragedy, but making sure the characters justify their place in the novel, behave logically, have hidden depths and interact properly with the central character is going to make your novel stronger and, ultimately, better.

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