Backstory is the building of a fictional life for a fictional character that's plausible, believable and provides a "factual" basis for the character's behavior. It can be short but seems to work best when it's 1-2 single spaced pages long.

Backstory is important because it's what motivates characters to take action or become immovable. When you're writing scenes, it's what will cause you to say to yourself, "She wouldn't do that!" or "He would never say that." That's because what you're trying to write is inconsistent with the backstory you've created. Spend time writing solid, colorful backstories because they are the foundation upon which your characters' lives are built.

Some of the many factors you might consider:

Environment: The town where he grew up; location (rural, metropolitan, suburbs, etc.), size of the town or city, the character's position in that town (unknown, well-known, popular, etc.).

Family: What sort of family? Functional, dysfunctional, controlling, bizarre, quirky, idyllic, etc. Describe it in detail.

Influencers: People in a character's life that changed them forever, be it a good influence or bad.

Events: Situations that indelibly mark a person for life; it could be a small, pivotal event or a major catastrophic disaster.

Character's Growth: Was she a painfully shy, despised child who's now outgoing and popular? How did she get that way?

Fears: Does he have an unnatural fear or phobia of some sort? Spiders, snakes, heights and water are all well-worn fears. Look for something unique and different.

Quirks: Strange or obsessive/compulsive behavior?

Work: Is she in a special or unusual job? Painfully dull occupation?

Passion: Is he passionate about something to the expense of something else? What is it? Animals? Politics? Eating meat? Environment? Pacificism? AIDS? Cancer? Wealth? Alcoholism?

History: Are there notable success or failures in the character's past?

Think of things that might set this person apart of everyday people? Always remember that we go to the movies to see what happens to different people, not "normal" people like ourselves. We're boring because we're like everyone else. I usually chuckle when I hear someone say how interesting their life has been and how it would make a great movie. No, it won't. It'll be boring, dull and lifeless. If the President of the United States can be boring, imagine how near-death the rest of us must be in comparison.

For the first draft, write at extremes! Make the good nearly saintly and the bad grotesque and despicable. It'll all get smoothed out when you re-write and edit.

Someone once advised that the secret to a good story was to place ordinary people in extraordinary circumstances. This is the premise of many films and novels. In "The Hunt for Red October," Alec Baldwin plays an obscure and low-level CIA analyst with allergies and a fear of heights who is thrust into the middle of the action. It works. Try doing the same.

Interesting characters cannot create themselves. They must be birthed, just as we were. They must have a history, regardless of their age in your story. That history must be cohesive and have shaped the character into the person you are portraying in your story. Breathe life into that history and your characters are more likely to come alive in the scenes you write.