So people talk and talk about the hero and heroine, but what about the supporting characters? They are just as important as our main characters. They add flavor, humor, contrast, stability or instability, etc.
Some minor characters are in the story for the duration while others are just passing through. But remember, they must always be there for a reason. We don’t care about the waitress unless she is part of the sting to get the hero caught. We might not care if the mechanic has one arm due to a car accident, unless the accident was caused by his obsession and jealousy of the heroine.
Always make sure secondary characters are people. Make the reader wonder about them. After all, they could be the killer or the long lost sibling, or even the catalyst that changes the entire complexity of the story. Never take supporting characters too lightly.
Having said that, don’t let these wonderful supporting characters take the story over. If the reader is too attracted to a secondary character (the handsome and charming investigator), we can’t help but wonder, ‘why doesn’t the heroine notice him?’ because the reader sure finds him irresistible.
Supporting characters are there to help us understand the circumstances surrounding the hero/heroine. Bear in mind, if they don’t, they should not be in the story. Period. Every character in your book must be in there for a reason.
Secondary characters should never be ‘flat characters.’ They must have personalities with internal and external motivations. They might even have particular traits or attitudes. If our hero/heroine cares about the supporting character, so does the reader. This also allows us to understand and like our main characters, which is one of the many reasons for having likeable or irritating supporting characters. Allow your characters to play off each other.
Always keep asking yourself, “Is the minor character doing his/her job?” If they’ve served their purpose it’s okay to eliminate them (kill them if you have to), but don’t keep them around because you’ve become fond of them.
Your main characters will most likely tell you if the supporting characters are getting out of line, listen to them. If in doubt, listen to the story and follow your instincts.