Dread

I have written and been a dungeon-master in a one-shot. Creating a world that players should be afraid of. The system of tabletop role-playing game I used was the Dread system, using a Jenga tower to dictate players moves. The most interesting and difficult part of the one-shot was coming up with scenarios on the fly based off players decisions, while I had a script written and optional routes for the players to take, I still had to come up with ways to lead the players back to the main path of the story.