How to Write Effective Supporting Characters

A story is only as strong as its weakest characters. Learn Hallie Ephron’s tips on how to write effective supporting characters, including balancing character traits, tormenting your hero, naming supporting characters, and more.

Sir Arthur Conan Doyle gave Sherlock Holmes a full panoply of supporting characters. There was Dr. Watson, the quintessential “sidekick,” to act as a sounding board; Scottish landlady Mrs. Hudson, to cook and clean and fuss over Holmes; Scotland Yard Inspector Lestrade, to provide a foil for Holmes’ intuitive brilliance, as well as access to official investigations; the Baker Street Irregulars, to ferret out information; and Mycroft Holmes, Sherlock’s politically powerful older brother, to provide financial and strategic support. Like Doyle’s, your cast of supporting characters should reflect what your protagonist needs.

Balancing Character Traits

An amateur sleuth needs a friend or relative with access to inside information—a police officer, a private investigator or a crime reporter will fit the bill. A character who’s arrogant and full of himself needs a character to keep him from taking himself too seriously, maybe an acerbic coworker or a mother. You might want to show a hardboiled police detective’s softer side by giving him kids or a pregnant wife.

The most important supporting character in many genres, though, is the sidekick. Virtually every mystery protagonist has one. Rex Stout’s obese, lazy, brilliant Nero Wolfe has Archie Goodwin—a slim, wisecracking ladies’ man. Carol O’Connell’s icy, statuesque, blonde Detective Kathy Mallory has garrulous, overweight, aging, alcoholic Detective Riker. Robert B. Parker’s literate, poetry-quoting Spenser has black, street-smart, tough-talking Hawk. Harlan Coben’s former basketball-star-turned-sports-agent, Myron Bolitar, has a rich, blond, preppy friend, Windsor Horne Lockwood, III.

See a pattern? It’s the old opposites attract. Mystery protagonists and their sidekicks are a study in contrasts. Sidekicks are the yin to the protagonists’ yang. The contrast puts the protagonists’ characteristics into relief. For instance, the thickheaded Watson makes Holmes look smarter.

The place to start in creating a sidekick is with the profile you developed of your sleuth, so think about what kind of opposites will work.

Tormenting Your Hero

Every protagonist/mystery sleuth needs an adversary, too. This is not the villain, but a good-guy character who drives your sleuth nuts, pushes his buttons, torments him, puts obstacles in his path, and is generally a pain in the patoot. It might be an overprotective relative or a know-it-all coworker. It might be a police officer or detective who “ain’t got no respect” for the protagonist. It might be a boss who’s a micromanager or a flirt.

For Sherlock Holmes, it’s Inspector Lestrade and his disdain for Holmes’ investigative techniques. In the same vein, Kathy Reichs’ forensic anthropologist Temperance Brennan has a tormentor in the person of Montreal police sergeant Luc Claudel. Their sparring is an ongoing element in her books. In Monday Mourning, Brennan finds out Claudel is going to be working with her on the case. She describes him:

Though a good cop, Luc Claudel has the patience of a firecracker, the sensitivity of Vlad the Impaler, and a persistent skepticism as to the value of forensic anthropology.

Then she adds:

Snappy dresser, though.

Conflict is the spice that makes characters come alive, and an adversary can cause the protagonist all kinds of interesting problems and complicate your story by throwing up roadblocks to the investigation.

An adversary may simply be thickheaded—for example, a superior officer who remains stubbornly unconvinced and takes the protagonist off the case. Or an adversary may be deliberately obstructive. For example, a bureaucrat’s elected boss might quash an investigation that threatens political cronies, or a senior reporter may fail to pass along information because he doesn’t want a junior reporter to get the scoop.

In developing an adversary, remember it should be a character who’s positioned to thwart, annoy, and generally get in your sleuth’s way. With an adversary in the story, the sleuth gets lots of opportunities to argue, struggle, and, in general, show his mettle and ingenuity.

Fleshing Out the Supporting Cast

A supporting character can be anyone in your sleuth’s life—a relative, a friend, a neighbor, a coworker, a professional colleague; the local librarian, waitress, town mayor; even a pet pooch. A supporting character may get ensnared in the plot and land in moral peril, or even take a turn as a suspect. In a series, supporting characters return from book to book and can have ongoing stories of their own.

Supporting characters come with baggage, so pick yours carefully. If you give your protagonist young kids, you’ll have to deal with arranging for child care. A significant other? Be prepared to handle the inevitable attraction to that sexy suspect. A pet Saint Bernard? Beware, he’ll have to be walked. Twice a day.

Supporting characters give your character life, but each one should also play a special role in the story. Supporting characters might start out as stereotypes: a devoted wife, a nagging mother-in-law, a bumbling assistant, a macho cop, or a slimy lawyer. It’s OK to typecast supporting characters during the planning phase. When you get into the writing, if you want them to play bigger roles, you’ll want to push past the stereotype and flesh them out, turning them into complex characters who do things that surprise you—and, in turn, the reader.

As a general rule, remember: You don’t want supporting characters to hog the spotlight, but bland and uninteresting characters shouldn’t be clogging up your story, either.

Naming Supporting Characters

Give each supporting character a name to match the persona, and be careful to pick names that help the reader remember who’s who.

Nicknames are easy to remember, especially when they provide a snapshot reminder of the character’s personality (Spike, Godiva, or Flash) or appearance (Red, Curly, or Smokey). Throwing in some ethnicity makes a character’s name easy to remember, too (Zito, Sasha, or Kwan). Avoid the dull and boring (Bob Miller) as well as the weirdly exotic (Dacron).

It’s not easy for readers to keep all your characters straight, so help them out. Don’t give a character two first names like William Thomas, Stanley Raymond, or Susan Frances. Vary the number of syllables in character names—it’s harder to confuse a Jane with a Stephanie than it is to confuse a Bob with a Hank. Pick names that don’t sound alike or start with the same letter. If your protagonist’s sister is Leanna, don’t name her best friend Lillian or Dana.

Create a list of names that you consider “keepers,” and add to it whenever you find a new one you like.

Introducing Minor Characters

Minor characters should make an impression when they come on the scene, just not a big splash. Here’s an example from Devices and Desires by P.D. James. With a flash of description, action, and dialogue, Manny Cummings makes his debut:

The door was already closing when he heard running footsteps and a cheerful shout, and Manny Cummings leapt in, just avoiding the bite of the closing steel. As always he seemed to whirl in a vortex of almost oppressive energy, too powerful to be contained by the lift’s four walls. He was brandishing a brown envelope. “Glad I caught you, Adam. It is Norfolk you’re escaping to, isn’t it? If the Norfolk CID do lay their hands on the Whistler, take a look at him for me, will you, check he isn’t our chap in Battersea.”

Is Manny tall or short? Fat or thin? Balding or sporting a crew cut? Who knows and who cares. It’s what he does that counts: He leaps into the elevator, arriving like a whirlwind, delivers three lines of dialogue with a hint of an Irish brogue, and gives the protagonist an all-important brown envelope that pushes the plot along.

A minor role is no place for a complex character. Don’t imbue one with a lot of mystery that your reader will expect you to explain. A name, a few quirky details, and a bit of action or dialogue are more effective than a long, drawn-out description.

Adding Authenticity

Remember that the world of your novel will also be full of walk-on characters who provide texture and realism. Each one may also have some small role in facilitating the plot, but for the most part, walk-on characters are there to make scenes feel authentic. Your protagonist takes a stroll, the street needs pedestrians; she goes to the bank to withdraw money, the bank needs bank tellers and security guards; and so on with hotel clerks, waitresses, salesmen, and all the rest.

When crafting your more important minor characters, don’t get carried away and forget that walk-ons should get no more than a sentence or two of introduction. They don’t need names, and a touch of description is plenty. Choose details that can be a kind of shorthand commentary on the neighborhood or context. Maybe the playground skateboarder is dressed in baggies and a Rasta hat. Or perhaps a PTA mother has a 4-carat rock on her finger.

Used in this way, walk-ons remain as many elements of setting as they are characters—and that setting will be a fitting backdrop to help both your protagonist and your more important supporting characters stand out.

When you take this online writing course, you will learn how to create believable fiction characters and construct scenes with emotional depth and range.

Hallie Ephron is the New York Times best-selling author of suspense and mystery novels. Her novels have been called “deliciously creepy” (Publishers Weekly), “gripping” (The Boston Globe), and “snaky and unsettling” (Seattle Times). She is a four-time finalist for the Mary Higgins Clark Award, recognizing excellence in suspense. Her novel Never Tell a Lie was turned into a movie for the Lifetime Movie Network. She wrote an On Crime book review column for The Boston Globe for more than ten years and won the Ellen Nehr Award for Excellence in Mystery Reviewing. The first edition of Writing and Selling Your Mystery Novel was an Edgar Award finalist. Hallie is a popular speaker and teaches writing at conferences nationally and internationally.