I wrote this article several years ago for the website High Level Games called 5 Steps to Make Monsters that Matter (A Halloween Special). It’s not exactly a pre-written module, but I do discuss how to make monsters or scenarios that feel seasonally-appropriate, while not relying on the cliches. In fact, @goobernuts you may be interested to be pinged on this, but I actually discuss inspiration from the Philippines in the article.
I’ve run some simple Dread sessions that are a lot of fun.
Normally I keep my prep pretty simple.
First I decide what is going on and write down rules that the setting/monster follows. This is probably the most important step, if you know what the horror will do then most other things fall into place.
Next I decide how much of this the players know at the start, and come up with an initial setup and make personalities for any NPCs that I think they will interact with.
Finally, I come up with 3-4 drastically different things that the players might do and come up with ways to handle them. If the players pick a way different from any of them (as almost always happens) I generally find that I can remix one of the things I prepped for a bit and use the information from it in a new scenario.
Lastly I write up the questionnaire and make sure that it includes questions about the PCs that are relevant to the setting, plus a few red herring questions that are completely irrelevant so that it doesn’t reveal what is going on. For instance, if the horror was based around, say, a supernatural killer, I’ll probably ask if the PC believes in the supernatural, but I’ll also ask if a PC thinks that space aliens have visited Earth.
It’s not a module, but I’m planning on running Black Mass by Will Jobst as a spooky one-shot this weekend. I’ve been running mostly OSR stuff for the past year, so this’ll be an adjustment, but I’m really inspired by the mechanics and vibe. I’ll report back after.
Given you mentioned Ravenloft, I hope you didn’t just mean “oneshot for D&D”. If you did, here come some recommendations you don’t wanna hear about!
Also instead of oneshots, they’re systems.
Excellent system, ships with several one-shot sized scenarios that you can interweave into a short campaign.
Exploring derelict ships in space! For if you’re curious about Mothership but want something super lightweight and super quickstart. Doesn’t ship with a oneshot, but has tables for generating ships and scenarios on the fly.
For a “Teens Exploring A Haunted House” micro-rpg derivative of Plasma Torch, check out SPOOKERS! by @dozens (That’s me!)