What makes for good horror?

Piggybacking off of Bookrat's question, Why do people find horror games fun?, what makes good horror in a game? How do you evoke the emotion of fear in a player sitting there munching potato chips and throwing dice? It's one thing to scare the characters, but how do you frighten the players, the way they would be frightened by a good horror movie?

I think what always works for me is if games go not for trying to scare me. Me sitting in front of my laptop and reading a game post isn't going to trigger my fight or flight response. But games can produce unease or discomfort, which can be really engaging.

One horror game I was playing in some time back that keeps popping up again in my head from time to time was really good at that and at making our characters feel completely helpless, whether that was one other PC standing by, unable to intervene as an armed person kidnapped a new friend they had just made in town or my character basically getting the facehugger treatment from Alien.

Player buy-in seems much more important in the horror genre compared to traditional heroic games to me. For stakes to be meaningful, there has to be some commitment and willingness to treat scenes seriously as their character would. Tone and immersion are pretty fraught to be broken otherwise.

Xcom Enemy unknown is the greatest Tactical shooter I've ever played.

Xcom enemy within is the greatest horror game I ever played.

Take an alien menace. We do what we need to for survival. Then we are betrayed with the fruits of our winning that war by other humans. We do even worse things to survive. The horror is the humanity and always will be.

Southern Gothic is my personal favorite horror theme.

I agree with bowlofspinach that in PbP, uneasiness and tension are probably better targets than fear per se. I was in a game of Cthulhu Confidential a couple years back, and the GM did a great job of this. That's a one-player, one-GM game, so it's already a bit tense as there's not a party to keep you safer. Then we leaned into a kind of David Lynchian atmosphere of weird, unsettling creepiness. I really dug it, but the GM unfortunately disappeared.

I agree with bowlofspinach and testlum, can't get legitimately scared from a game but the feeling of helplessness when you're fully invested in a character is fairly disturbing. It's definitely something you have to build up to over the course of the game...

I played in a Delta Green game a while back (maybe with WhtKnt?) and we all got very into the roleplaying such that when the horror was finally revealed in the falling action and my agent went mad at the sight of it and accidentally killed another player in his black out... Man, I felt that.

I guess I can also highlight this scene for good horror again.

I don't even know why it worked so well for me. I think it was also a sense of helplessness. My character was in some serious danger and didn't even know it. And her friend knew about the danger but wasn't in a situation to intervene. Plus the jumpscare of opening the spoiler tag added something to it 😄

For me, good horror is about good descriptions of the scene which then help evoke the emotions associated with horror. It can be fear, disgust, dread, uncertainty (especially of the unknown) - all of which are usually associated with death, pain, or the realization that your reality is not what you thought it was.

A GM should not just state what it is the characters are seeing, but instead should describe the sights, sounds, smells, emotions, visceral reactions, uncertainty, uncontrollable emotions, and more that are associated with what the PCs face. Additionally, there should be prep work associated with this - building up to it with unseen sounds and smells, clues that suggest not all it what it seems, and more. Build-up is hugely important.

"Show, don't tell" as the saying goes.

However, it's possible to numb your players/PCs to horror. Good horror is an emotional rollercoaster. It needs to have breaks in the fear, stop points for laughter or at least a sense of calmness or safety. Then, rip it away when it's unexpected and you can get a good jump scare. (If you think that can't be done in PbP games, think again - I've done it!).

Even with all that, you need good buy-in from your players. Encourage players to be descriptive with their PCs, especially with their emotions. Emotions play a huge part of horror, and without the emotional impact of fright, you're never going to get a good story. It's not just emotions like anger, disgust, fear, etc... Players can also speak to their racing heartbeats, butterflies in their stomach, nervousness, a rumbling gut, and other physiological symptoms. Or players can write flashbacks which show why this particular scene is especially horrifying to them, personally.