I dropped out of college to go be an actor. For year, I apprenticed myself to an incredible actress who relentlessly demanded I understand my character.
I use the same techniques when I’m writing. In fact, I go a little overboard and feel what the characters are feeling… it’s exhausting. But the fundamentals are sound.
Who is this person?
Hopefully, they already have a purpose in your story. Don’t think this only applies to your main characters, either. I think this is worth asking regardless. The ragged bum who shares a drunken glance with your hero, as he staggers from the tavern — he has a purpose. He has goals. What are they?
Why are they the way they are?
Years ago, I played Max in a production of Sound of Music. Like a good little actor, I spent weeks learning everything I could about the politics and history of Austria in the 1920s and 30s. What I learned is than the Anschluss wasn’t really a singular event. Austria experienced lots of violent political upheaval following the first World War. Max is a politician. So naturally, his primary motivation is to keep the knives from coming for him. Once I understood that, his every choice and action in the rest of the show make sense. Max wants to be on the winning side, because that’s his only hope of surviving.
You may not need to do that level of research, but you do need to know what the formative events are that shape your character’s choices. They need not all be huge or dramatic. At this moment in my life, I’m trying to get a handle on a dust mite allergy. It’s new. I don’t know how to properly manage it. And sometimes I’m not getting a decent night’s sleep for a week at a time. In those moments almost everything in my life is filtered through a foggy, reactive lens of exhaustion. I just want to sleep!
What do they want?
So figure it out. Every time your character walks into a scene, ask yourself: what do they want out of this interaction, this conversation, this moment. Ideally, it should run squarely against the desires and goals of the other characters they’re interacting with. Nobody wants to read a novel about how much everyone agrees.
There’s a second useful layer to this one. In addition to determining what the character wants in each scene, determine what they say they want. That doesn’t mean they should always explicitly state their goals. The point is, that most of us go into things with mixed motives. We put our good guy face on, and make every effort to pursue what we perceive as the public good. But there’s also an underlying motive. The one we don’t want to tell people. So hopefully you’ve got the underlying motive worked out. But don’t skip the excuse. What’s their justification? How would they make this goal sound noble? If you’re writing dialog, there’s a good chance that as the conflict rises, some of those justifications are going to come tumbling out.
There’s lots more that goes into making a compelling character, but this is already a long post. So I’ll toss out some more questions in a few days.