Characters fail if they’re one-dimensional. Douglass Adams gives us the answer to the problem in the company slogan for the Sirius Cybernetics Corporation from the “Hitch Hikers Guide to the Galaxy”: “… real people personalities.”
A good character should engender some kind of identification for your reader. The character should have feelings, opinions, and a unique voice. This applies equally to villains!
I hate to pull things from the news, but I feel as though it makes a reasonable point.
The young man who shot up the movie theater in Colorado, prior to his killing spree, seemed like just your normal depressed person. He is a son, a Uni dropout, and someone who’s inner demons pushed well-past normal human endurance. I can identify with him to a degree, because I’ve felt worthless, on the edge, and alone.
It doesn’t mean I’m about to go massacre people, but that I experience some compassion for his pain. I can’t condone what he did.
I also identify with the victims of that attack, not from direct experience of being shot at, but from a similar place of powerlessness. All I can do is manage to survive, and if the horrible things around me go away, I’ll be immensely grateful.
Let me tilt this condo away from tragedy for a moment. Relating to people and characters is about touching on universal human experiences. This is the same principle I wrote about in my post about monsters. Emotional attachment, hatred, and fear, are grounded in primal human experience.
An exercise for “humanizing” your characters is starting a separate document and writing some of their backstory…even as far back as their childhood. Once again, this goes for your bad guys (provided they’re human), too. You may find it helpful as you write your primary project, and it might be so good you want to include it as a flashback.
The more important the character, the more you might want to consider giving this a try.
Another trick is to “interview” your character. Write down a list of plot-pertinent questions, and then respond to them as the character would. Get as imaginative as you like! Pretending to be that character, answering the questions, can give you a unique feel for that voice.
I hope all is well with you out there.