When it comes to encounter design in horror games I think about this image a lot.
Horror games require really intentional environmental encounters in order to build tension. If this was Moldvay Basic I’d replace tricks on the dungeon stocking table with “environmental horror.”
This is huge and it’s easy to forget. But if you put monsters or other people into all your horror encounters, then 9/10 times you’re releasing more tension than you’re building.
Environmental encounters are questions. In Mothership we call these encounters “omens.” They signal that something is coming. The question is, what?
It’s the players who ask these questions. And their imaginations fill in the holes. Asking the question gives negative space to the horror. But when you finally reveal it the tension is gone. The shape is solidified.
These omens are a way of sculpting your horror until you finally reveal it, releasing the tension you’ve built over the entire session.
So, next time you’re building a horror scenario for your game, remember that the environment is always asking a question. What happened here? Who did this? Where is everyone? Sitting with those questions unanswered is what creates tension and horror.
Do you find that these environmental horror moments work best when sprinkled in on an improvisational basis based on the needs of the session or do you find a ratio of dread, dread, payoff in how you layout how information is being given to players?
I tend to work heavily in improv at the table and am trying to reassess how much work I do in planning to keep my stories tight while maintaining the narrative punch that can come from tailoring a situation to what’s happening at the table.
I feel like where the pacing tension of a lot of DND-likes is the management of resources in a high risk/high reward setting, for horror games the pacing tension is instilling a sense of dread and closely cultivating it through play. I want to say it's more important than getting the rules 100%.
Two of my favorite moments in horror gaming came from the same session of Gradient Descent I ran, where a player playing a scientist legitimately fell into the "are you a human" issue and actually started freaking out IRL and then 30 minutes later the dread got so bad they started believing the android player had spoken to me privately about betraying them (they didn't).
All of that comes from what you mentioned, environmental horror, because it builds up dread. You start to think something is WAY worse than it may actually be.