Everybody Has An Excuse

I've heard it said that nobody thinks they're a villain. I could argue against that to some degree (there are always exceptions - some people do believe it's fun to do bad things), but in general, I've found it to be correct. The point of the saying is to debunk the classic fairytale stories we are used to.

Villains are such one-dimensional caricatures that you can't take them seriously. They may be strong and willing to use their strength to harm people, but they aren't believable as people. Nobody spends their life studying black magic for the heck of it. Nobody decides they are going to rule the world with an iron fist because it would be fun.

Whatever a person chooses to do, that choice is justified in their mind. Everybody has an excuse. It may be thin, flimsy, even contradictory to other held beliefs. But they all think they're doing the right thing (or the wrong thing for the right reasons).

This goes directly with the idea of motivation. There is always a reason why people do any given thing. Something pushed them into that decision. So when you are looking at your "bad guy" characters, figure out what their motivation is, and why they think the things they do are right. Similarly, examine your protagonist and think about ways that he or she may be seen as the villain.