Have you ever been in the middle of a good book and find it completely destroyed by a horrible villain? Or the opposite happens and you can hardly stand reading the book but the villain is wonderful? That doesn't happen very often.

There are two big mistakes that most people make when writing a villain. The first is that he's completely impotent. He's not a bad guy, he's an angry character that doesn't do anything. You know those horrible movie villains? It's like that only worse. "I'll get you Austin Powers. But first I'm going to hide over here and plot until the writer finds something better for me to do." It's so disappointing to see it happen.

The second is that the bad guy is so bad it's impossible to believe. You'll see a villain that's a sexual deviant and a psychopath and at the same time shoots lightning bolts out of his butt. He's a genius and yet he blends in with the background so the hero somehow doesn't notice that the bad guy is going to kill him in the end. Please spare us. A sexually deviant villain isn't believable and may offend some of your target audience. Just because the villain has a fancy for chains and a ball gag, that doesn't make him a bad guy. If he's a psychopath, give a reason for him to be like that. If he has special powers, make it possible (or as possible as you can with supernatural characters).

I will admit that I made the sexual deviant mistake. But I was called out on it so many times that I had to change it (NP, you'll be happy about that. Prophecy doesn't have a sexually deviant villain in the published version). Now I have a villain that's insane, but he's insane and bent on revenge. That doesn't even really do him justice.

I guess the point you need to remember is that a villain is a character, just like your hero. Map him or her out and make him or her believable. Give them purpose and make people either hate them or fear them or whatever you feel like doing. But for the sake of anyone who will read your novel, remember to make the villain believable. And please stay away from lightning bolts coming from his butt.