...if there's been much writing done on TTRPGs specifically built for an asynchronous format?
Before I played TTRPGs, I used to do text-based RP in Gaia Online. I remember them having a rudimentary D6 Roller built in, but no RP was interested in actually adjudicating itself through game mechanics.
Obviously Correspondence Play has been around for decades; but could a system exist that lets a bunch of players drop in and out asynchronously?
