Checking to see if folks would be interested in playing some Cheat Your Own Adventure. The game simulates kids' Choose Your Own Adventure books. Play starts with the oldest player writing a couple paragraphs starting an adventure. The other players then write choices for the narrator (e.g., to look in the old well, turn to page 5; to punch the clown, turn to page 43; to check Google for information on the mysterious janitor, turn to page 18; etc.). The narrator picks one of the options. A die roll determines whether the choice is successful. If the choice works out, the player who came up with that option takes over the story until a new decision point is reached. If the choice is unsuccessful, the player who came up with the option writes a fun death scene, then the narrator picks another option (which is always successful, so play moves forward). The game ends after 12 decision points are completed.
The game seems like a very good fit for PBP. You can download the rules (all 2 pages of them) for free
here.