Why do we sometimes say that a person we know is “quite a character”? You know the type I'm talking about. This person is distinctive, amusing, mystical, humorous, larger than life, etc. In a word: Interesting.
Characters in a book can't be run of the mill. They need to be interesting, so that your readers will want to hang out with them for the course of the book.
They need to be flawed yet likeable, or if not likeable, have at least one redeeming quality. You’re asking your reader to spend several hours hanging out with your protagonist, which can be tough to do if he or she is boring or unpleasant.
Let’s look at what is possibly the most famous character in mystery fiction of all time: Sherlock Holmes.
Sir Conan Doyle’s gave his character a good balance of likable characteristics, eccentricities and flaws.
Physically Sherlock Holmes is tall, thin and lithe. No one would call him an especially handsome man, but he’s well-dressed for the era, with the flare of what we’d now coin as “metro-sexual”. He smokes a pipe and on occasion even sniffs cocaine.
He’s a workaholic, and generally a one-man show with only the help of his friend, Dr. Watson. With limited forensic resources Sherlock uses deductive reasoning, cause and effect, and logic to solve his cases.
He’s the consummate bachelor, married to his work. The only girl to capture his heart is Irene Adler, and she did so because she managed to outwit him.
He’s unorganized, and lacks social skills and graces, but is tolerated and sought out because of his genius.
I love the well-known TV character Gregory House from HOUSE.
He could’ve been written as a stereotype doctor: compassionate, good bedside manner, intelligent yet unpretentious. Married with kids. Drives an expensive car.
Instead they wrote him to be the opposite of all of these characteristics (except for his IQ). House is curious, a puzzler, not innately compassionate. His bedside manner is gruff and insensitive. He’s single, and bitter over his last break up. He walks with a cane and is addicted to pain killers. He drives a motorbike.
Yet despite this quite lengthy list of flaws his character is compelling. He’s like a train wreck and we can’t but help to stop and stare. He shouldn’t be likeable, but he’s charming enough to fool us, pulling us into his world, and we’re left rooting for him, even if we’re not sure why.
This is masterful characterization.
His character arc over the course of 8 seasons ( you can think of this as an eight book series.) Many writers would take him from the broken mess he is at the beginning and find a way to fix him by the end. The writers of the show once again did the opposite. The character Gregory House arced beautifully, but instead of arcing from bad to good, he arced from bad to worse than bad. Terrific writing.
To form interesting characters you need character arc, felt need, flaws (and corresponding redeeming factor), distinctive character voice and details.
To sum up the character of Gregory House:
Character arc: bad to worse than bad
Felt need: to regain control of his life after having his heart broken and his leg mangled. Manifests in solving medical problems. Saving lives is a fringe benefit.
Flaws: self-important, inconsiderate, belligerent, selfish, doesn’t filter himself
Redeeming factor: Is is able to fall in love again, and on occasion, consider the needs of others.
Distinctive character voice: witty and sarcastic
Details: tall, thin, forty-something, wears a blazer over a T-shirt and jeans (instead of a shirt, tie and slacks like every other male doctor wears), refuses to wear a lab coat, walks with a limp and a cane.