Here's a very lucid essay from WRITER'S DIGEST about the differences between flat (two-dimensional) and round (three-dimensional) characters:
Flat vs. RoundIt defines the two types with lists of the principal traits of each, followed by analyses of several well-known examples from literature.
This article brings up a few points I hadn't thought of before:
An archetype is often a flat character. Although the article doesn't say it in so many words, this type of character's larger-than-life traits lend themselves to the "flat" treatment.
A flat character can be a protagonist. "Generally, the main characters are round, and the supporting ones are flat—but you’ll soon see this isn’t always the case."
"Round" and "flat" are not identical to dynamic versus static. Not all rounded characters change over the course of the story.
Some points not explicitly discussed that are worth emphasizing: Flat characters aren't necessarily stereotypes or cliches. A flat character can still be a believable individual. Not all the people in a work of fiction have to be rounded; trying to accomplish that goal in a full-length novel would be not only exhausting for both author and reader but, in fact, unrealistic. Most of the people we meet daily in real life remain "flat" to us. One typical trait listed for flat characters is that their responses and actions are predictable, a premise I'm dubious about. Sydney Carton's self-sacrifice at the end of A TALE OF TWO CITIES, for example, would probably come as a surprising plot twist to a reader unfamiliar with the story. Also, the two types may be seen as falling on a continuum rather than fitting into a strict binary distinction. Sydney Carton, while "flatter" than Charles Darnay in that novel, is "rounder" than Madame Defarge. David Copperfield's great-aunt Betsey is less rounded than David but more so than Mr. Micawber or Uriah Heep.
One classic literary figure presented in the essay as an example of a flat character is Sherlock Holmes. As the central figure in his series, he's fascinating, but without the complexity and depth of a fully rounded character.
Can a character transform from one type to the other? It could be argued that Hannibal Lecter is mainly flat in RED DRAGON and SILENCE OF THE LAMBS but becomes a rounded character in HANNIBAL and HANNIBAL RISING (a shift many readers and critics consider a change for the worse).
Margaret L. Carter
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