Horror, like all genres, seems to find itself bleeding into a lot more stories than just the ones you might call “Horror Stories”. If a story is about two people falling in love but someone is the story gets brutally murdered, does that make it a horror or a romance? If a story is about a psychopathic killer chasing down a group teens and slaughtering them but it’s set on a futuristic space colony, is that movie a horror or a sci-fi?
The answer is both.
Very few stories fit neatly into a single genre, and if they do even fewer of those are any good. Good stories come from drama, from tension and resolution. The more angles to the tension, the more complex the story, and the more satisfying it is when all of that tension is resolved. What defines the main genre of a story is the angle of the strongest tension.
For a story to be considered a horror the tension must primarily come from circumstances with horrific stakes.
“Yeah, duh. Of course horror comes from horrific things.” You might be sitting there thinking, and you’d be right. But it still resonates as point of confusion amongst those determined to place every story into a particular genre defined category.
The stakes in a romance story usually fall into whether two people will end up happy together or miserable apart, something very emotionally substantial The stakes in horror are usually much more survivalist: to die horribly, to be damned to hell, to be corrupted, to lose what it means to be human, to do horrific things.
The trick to truly defined horror is to be able to put value into those stakes. It’s easy to write story where someone gets there guts torn out and most would call that “torture porn” or a “slasher flick” and slap the “horror” label on it. But if that’s all there is to the story I’m more inclined to call it “bad horror” or just plain “bad” Bad because stakes mean nothing and consequences can’t be horrific if the person experiencing the story doesn’t care about the characters in the story. And if the stakes aren’t horrific to the audience then the story isn’t horror.
Which in a strange way means that horror is defined by compassion. It is defined by seeing things that we care about threatened and taken from us. It’s about having to deal with the loss of things that matter, whether that thing is a friend, your soul, or even just your guts (and by extension your life).It’s about confronting the parts of ourselves and the parts of the world that scare us. It’s about learning whether we can overcome that fear or whether we will succumb to it. That’s what defines horror.
A wonderful book on the subject of the horror genre as a whole (particularly older horror) is Stephen King's Danse Macarbe. It goes into great detail about some of the archetype of horror villians, about the some of the classic tropes, and how context can influence story and horror, it's a great read and it's written in King's easy to digest prose.