I talked a bit last week about the importance of giving your main character a goal, stated clearly at the beginning of the story. Otherwise they’re just aimlessly wandering around, and if they get from A to B, it’s by accident rather than design, and where’s the story in that? If Darth Vader hadn’t wanted to rule the entire universe, he wouldn’t have been much of a bad dude. He’d just have been a weirdo in a plastic suit.
But more than just a goal, a character has to have good reasons for pursuing that goal (it’s up to you to decide whether the lure of the dark side was a good reason or not). Luke wanted to leave his home planet because it was a boring, lifeless dustbowl. I can get with that. There was a little conflict in the shape of his aunt and uncle, who he wasn’t quite ready to leave behind, but that problem was dealt with quite neatly (or smokily, depending on your point of view). Han Solo wanted money because there was a price on his head, and he didn’t really want to die. Princess Leia wanted to cop off with Han Solo because he was, you know, Han Solo (enough said).
When you give a character a reason to do something, that reason has to make sense to the reader, otherwise they’ll think your character is an idiot. You know the blonde girl who always goes to investigate the weird noise in the basement at the beginning of a horror film? She’s TSTL. Why does she go there? WHY? Hasn’t she watched Nightmare on Elm Street? Doesn’t she know ANYTHING? Do this, and you’ll turn your reader off. Unless, of course, you want them to think the character is an idiot. In which case, go right ahead 🙂