A round character is one who is multidimensional, revealing the complexity and contradictions that are so much a part of human nature. E.M. Forster, who first used the phrase in Aspects of the Novel, wrote that the true test of roundness is in a character’s ability to surprise in a convincing way. The round character stands in contrast to the flat character, a term also coined by Forster. Flat characters tend to be defined by a single trait. They usually remain unchanged.
Miss Amelia, a central character in Carson McCullers’ The Ballad of the Sad Café, is a round character. She runs the town store and operates a still that makes the best liquor in the county. She isn’t at ease with other people and spends most of her time alone. Her only use of others is to “make money out of them” and she engages in lawsuits over mere trifles. Still, she acts as the town doctor, trying out remedies on herself before giving them to others and, generously, charges no fee for her services. When Cousin Lymon, a hunchback claiming to be her kin, comes into town, the reader sees yet another side of her character. She gives him free liquor and invites him in to dinner—kindnesses she never extended to her fellow townspeople. She even lets Cousin Lymon move in with her.
Merlie Ryan, on the other hand, is a flat character. He has three-day malaria, “which means that every third day the fever comes on him.” And, start to finish, he’s a rumor-monger. When Cousin Lymon doesn’t emerge from Miss Amelia’s house the day after he spends his first night there, Merlie starts the rumor that Miss Amelia murdered Cousin Lymon for something in his suitcase. Merlie appears throughout the novella—playing checkers at Miss Amelia’s café when it eventually opens, in the audience of townspeople at other events of the story, as the source of other unsubstantiated rumors—but he remains one-dimensional.
Central characters should be round. You can create this dimensionality by showing multiple facets of the character’s personality. The grumpy security guard isn’t grumpy twenty-four hours a day, every single day. He may be a grouch at work, but he might show focus and determination at his racquetball tournament on the weekend. Or he might squirrel away candies during the week to give to his five year old neighbor the next time their paths cross. Maybe he has a frown on his face when he gives them to her; but the fact that he thinks of it at all shows another side of his personality.
Flat characters have a bad reputation—and with good reason. A flat character attempting to fill the shoes of a main character will make for a lackluster reading experience. But not all characters need to be round. The shoe salesman who appears only to sell your main character a pair of expensive designer heels after her long-sought-after promotion need not have dimensionality. It’s only important that he sells her the shoes and, in doing so, makes her feel like a member of the elite, a status for which she’s been yearning. To make him a round character would take the attention away from her experience, overshadowing what’s important in the scene. And it can mislead the reader, who may be expecting to see more of this salesman since so much attention went into building his character.
Don’t hesitate to use both kinds of characters—just remember each kind has a very specific purpose.