itch.io

Dice and Improv World:

https://connor-prime.itch.io/dice-and-impov-world-a-collaborative-worldbuiling-s...

A simple (3 - 6 page) system that's essentially people coming up with 2 ideas and rolling to pick one. The game follows a 3 - act structure of development, rising tension, and climax.

It's a lot of fun using this city generator (by Watabou) to help come up with ideas:

https://watabou.github.io/city-generator/