What’s not to love about a good villain? I can’t be the only person who thinks that, right? I catch myself pulling for villains in horror films and movies more than I find myself liking the protagonist. That’s always been kind of interesting to me. Why should the hero be the only complex character? The only interesting ones? Well, they sure to hell shouldn’t be. Good guys are pretty tightly bound into what they can and can’t do. This is of course only talking about the very stark hero/villain dichotomy that’s the most common in fiction. Anti-heroes are a whole other thing. I’ll get into them another time.
Inconsistency. A villain can be erratic only if mental illness is an element. And even then, you have to research the fuck out of the mental illness. That way your inconsistent behavior is really genuine to the behavior of people with said illness(es). Too often movie and literary villains act so inconsistently that you have no idea what the hell they’re about. The way to fix this? Have a set idea of what their motivation is. Their thought processes. What they’re about. Their end game. Know why they want what they want. Be consistent with that kind of shit or you just end up with a very confusing mess of a creative work.
They can’t only exist in the context of the hero. This one really gets on my damned nerves. A villain is a character, just like the hero. In a lot of cases, the villain is actually the central character. See also: Misery. But just because your villain is in fact a villain, that doesn’t mean that they should be boring. They should be as complex, if not more than your actual Hero. Because they have a lot more room to be complex in most cases. The villain is the hero of the story if it’s told from their point of view. Don’t forget that when you’re making them do monstrous things. They always have a reason to do them. And it’s your job as a benevolent overlord to figure out what that is.
They can’t act like morons when they’re actually smart beings. The age-old idiocy of a villain that’s waiting on something to begin their master plan. For no apparent reason. There’s no real logic to why they’re holding back. But they do it anyway. And it’s nonsensical for them to do this. Even when they’re an allegedly intelligent person. Smart people are governed by logic, unless the mental illness element I mentioned earlier kicks in. And even then, there’s a rhyme and reason.
Not having a good backstory is a huge mistake. Or even not really having one at all. An example of this done well is the character of Tom Riddle in Harry Potter. You take a truly heinous villain like Voldemort. He orphans a child he intended to kill. He starts a war. He killed or had killed a metric fuck ton of people. Innocent or otherwise. But then the brilliantly manipulative JK Rowling takes us back a while. We see him as a little orphan boy, not too dissimilar to our own Harry. We see him as a student. Very much alone and shunned. And in some ways he starts to make sense. That kind of thing is crucial.
Shades of grey are important when writing a good villain. And you have to know what governs them to do what they do. It’s entirely possible for the villain to do something incredibly selfless and kind. It all kind of depends on what makes them villainous. Those things are important to know before you ever start writing them. A hero can be a little boring. A little stiff. But if your villain is trite, you’re dead in the water.