Ovinomancer
No flips for you!
i absolutely agree, which is why I used the term GM-full (with a typo!), as in the table is full of GMs. I did also use GM-less as it was the term used by the poster I was responding to.
Contrasting just with GM-full is probably a simplification of a spectrum, from the GM is a god whose word is unquestionable and is solely responsible for all fun at one end, through to the GM is running the game but is open to ideas and discussion, to AW MCing, and finally to equally shared responsibility for authoring at the other end. I doubt many groups are playing at the extremes of this spectrum most of the time.
I forgot to mention a bunch of other great GM-full games like Microscope (great campaign starter) and Kingdom.
Happy gaming.
See, I disagree. Without asking for specific duties and authorities that constitute the "GM role", we can say that whatever these are they must be severable -- ie, exercising one of these authorities does not necessarily entail the ability to exercise all of the authorities. In fact, in many games with a GM, the specific authorities are defined and do not constitute the same set of authorities. Sure, D&D uses the "GM has all authority" model, but this would entail that all authorities are the GM's role, as the ability to exercise a veto is the control of a thing. Given that there's an assumed "Player role" as well, then it can't be the case that the GM's role can be so defined as it leaves no authorities for the player. This is actually a point often made about D&D in favor of the GM's authority, so I'm not on terribly shaky ground here.
All that said, if the GM's role isn't well defined, and the individual authorities are severable, then it's hard to say that there is a definable GM's role rather than a number of authorities that many games assign to the GM. Enough so that it's really not useful analysis at all to refer to the GM's role for this bucket, but rather to discuss how the specific authorities are distributed. Refering to a shifting bucket of authorities as the "GM's role" doesn't illuminate what's happening in play, but obscures it. I will concede it's possibly useful in introducing concepts of a game to new players that are steeped in D&D-style authorities, in that it frames the game inside their limited reference experience, but, past that, it's just not helpful at all.