Small God of the Dozens
I wasn't actually specifically indexing rules light as the key measure of complexity, although most people in the thread do seem to be doing so. I mentioned BW more because of the cognitive load of meshing the various systems (the spokes and rim to use their terms) into functional gameplay, on both sides of the screen really. BW certainly can and does collapse back to basic principles in a moment of doubt, much in the same way as PbtA games do, but it is also a game that explicitly references system mastery as a goal of play and a game that, perhaps more than any other I'm aware of, rewards increasing system mastery with increasingly positive play experiences. Anyway, that's my two cents.It's certainly not rules light! But I don't think it's as complex as RM.