@stellarskylark TinyMUD did the kind of player-created storytelling you're talking about, right? Maybe that's good inspiration for how little you can get away with in gameplay mechanics (it ran 30+ years ago on machines with mere megabytes of RAM) while still enabling people to tell stories together. https://mud.fandom.com/wiki/TinyMUD

My undergrad college advisor got it running in the early 2000s, got a room full of high school students to come play it for a day, and roped me and a couple other college students into helping moderate the experience. There was only one kid who we had to banish to a room by himself so he'd quit breaking the things other people were trying to create, so it was arguably a pretty successful day.