Several people spoke of various things--"realism", plausibility, consistency, etc.--as limitations on GM action. I don't know if anyone used that specific phrasing, but there were
repeated assertions that there were limits of some kind, and those limits were genuinely
external to the GM. That's why I've kept asking, repeatedly, where the
external limits are. Because I was told they were there.
I wouldn't be asking this if I hadn't been told,
repeatedly, that such things were there. I have no interest in "scoring points" or "catching" people in some trap or whatever. I have better things to spend my time doing.
I'm simply asking
because I was told they were there. If they aren't, that's fine, though I do think it affects some of the other arguments made, if the (alleged) limitations, guidelines, constraints, whatever-we-wish-to-call-them are not in fact external to the GM as was previously described.
Because, contra what you've said above, that IS the way that those advocating this particular style HAVE argued that their position is special and different and not like other styles. That theirs is "realistic", or "consistent", or that it articulates a world that "really exists", or various other claims, and that any other style
does not achieve this state (with the usual jab, implicit or explicit, that the kinds of games
@pemerton speaks of not only don't do this, they
cannot do this even in principle, for various alleged reasons.) That the GM isn't doing things because they feel like it and exercising their individual judgment acting on their individual preferences, but rather that they set up something and then have to abide by it regardless of--indeed, utterly disconnected from--any personal preference for what could or could not happen, what does or does not matter, what should or should not result from a given action.
Pretty much the only thing I've gotten thus far, the only actually concrete
thing, is a commitment to what video games call a "persistent world", from an actually pretty productive exchange where I clarified my terms and someone else clarified theirs, rather than either of us just flat-out declaring "I can't explain it, you just have to accept it". I don't know if "persistent world" is the phrase fans of this style would welcome (it is, after all, a term from video games and that can raise hackles in any TTRPG discussion), but I will continue to use it, with quotes, unless/until someone challenges it and offers at least some kind of alternative they prefer, to at least cut down a little on the back-and-forth.
A commitment to a "persistent world" does in fact entail some, minor, limitations on the GM. They're still very soft limitations, since original input is still 100% under their control and inputs that have not yet been made available to the PCs may be changed at any time without breaking that commitment, but they're limitations nonetheless and that's
something. In specific, with a persistent world, the GM is pretty much hard-required to continue iterating on things in places the PCs are liable to go, even if they don't actually do so, and significant changes require commensurate justification. I consider that an extremely low bar, but it isn't a bar below the floor (like the "wait several months" answer, that's very much a through-the-floor hurdle, because several months is
plenty of time for a GM to just invent whatever they want and rigorously check it for holes or issues.)