Yeah, I see what you're saying, but wouldn't that require a lot of random generation of encounters/dungeons/whatever?
No? Why would it? The world is established from some particular moment. It might be of the DM's creation, or it might be precisely an already-published one (e.g. Dark Sun, Al Qadim, Forgotten Realms, Planescape, etc.), or something blending the two. However,
once the world is set in motion, it simply is what it is. This will occasionally require the DM to act "as the world," because the world cannot generate itself, but he does so adhering to what has already been established about the world. E.g. "goblins live in the north" is established; the players enter a cave system in goblin lands; the DM thus populates it with goblins (who claim this territory) and ecologically-appropriate monsters. This is not the DM unilaterally declaring things; this is the DM accepting the already-defined input from the world, processing it, and then contributing something which is consistent. The "processing" part
could involve random generation, but it does not have to.
I can see how if there is an agreement by all concerned to play through a given adventure module as written or all random encounters then the DM's role is definitely reduced to one of impartial referee and rolls should not be fudged. A specific contract has been entered into by all concerned.
To be honest though, other than a weird experiment, I can't imagine wanting to play that way as either a PC or DM.
Well, firstly, it doesn't have to be a prewritten adventure module. The world COULD be entirely of the DM's original creation; the point is that
once something is created, it ONLY and EXCLUSIVELY advances as if it were a "real" entity operating by clear, definite rules and laws. This is where the "rules as physics" idea comes from--the DM's part to play in the world is only to (a) advance the world-system forward in time, following the defined rules for such, and (b) extrapolate, in those places where the pre-definition is incomplete or indefinite, what parts would/should be there to make a whole and rationally proceeding system. (Edit: And just in case this isn't clear, the simulationist DM finds it extremely satisfying to find out "what will the PCs do?" when they encounter this "naturally progressing" world, which will of course respond back to what the players do, etc. ad infinitum. It's very roughly analogous to a scientist observing patterns as a dynamic system advances and changes.)
You could say that Eberron--a very popular setting, as I understand it--comes straight out of this idea. It took the 3e ruleset and said, "Y'know what? Let's ACTUALLY start from these as first principles, add some color and society and story, and
see what happens."
It's the "see what happens" part that matters, here--and this is where "simulationism" gets its jollies. I'm not real big on simulationism per se; though I dispute GNS theory's validity, if I *had* to accept it I would consider myself a deep gamist/narrativist hybrid (I want to both
enjoy playing a game AND
enjoy experiencing a story, simultaneously).
Secondly, there are other kinds of contracts--which have nothing to do with simulationism--that would quite easily lead to the same conclusion. For example, "We want to earn our victories--and defeats--purely on our own merits." That's a largely agnostic premise (that is, it can be framed for any part of GNS), but it expressly forbids fudging. In gamist terms, it would probably be more specifically phrased as, "We want to play a game with consistent rules that do not change, even if that means we sometimes lose/are defeated." In narrativist terms, it would probably be, "We want to experience the ups and downs of the story
only because of the choices we have made in it."
There's also, as I've said already, the simple problem of "if you are concealing the truth,
even when directly questioned, because it would upset people...why are you so adamant that this is a perfectly okay thing to do?" If you're doing something that upsets someone, and then hiding it from them to avoid making them upset, it sounds to me like you don't actually care about what they think, you care about
controlling what they think--and I find that pretty offensive.
To each their own I guess.
While that's a given, it's a given that is good to reiterate. So...yes, exactly.
