Campbell
Relaxed Intensity
I think this is missing how others approach the game. Obviously none of this stuff is real, but to say it only exists the moment it is introduced in play or 'on screen', is simply not the case in a number of playstyles. For one, you often create material between games, with the expecation that that material is pretty much set (certainly you can make changes to it on the fly for a variety of reasons, but I think when most GMs create a setting map, even if the players haven't been to the north, they treat the desert they put there as set, and as existing, even if the players never encounter it). Further the whole concept of living adventure and the world in motion, is the idea that the GM is considering what the NPCs are doing when they are not on screen. Some of us even track this stuff (I have blog entries on how to track NPC movements to create a real sense of objective NPCs moving around independently and just as restrained by speed considerations as the party). Again, none of this is real, but the point is the GM in a living adventure or in a world in motion, is expected to treat those things as being the same level of real as the stuff that happens 'on screen'.
There are all sorts of ways that something can be established in the shared fiction. One of those ways is by the GM referencing prepared material, thinking offscreen, and making judgement calls based on what they think is likely to be true. The world does not suddenly really become in motion because of that. The GM is still animating it. I have played and run plenty of games like this. It's good stuff,
I'm trying to talk about the real world process. Not how we think about it in the act of play. This is why the way Kevin Crawford and Justin Alexander talk about scenario design so powerful. They speak to the real world process.