I am not going to respond to the thrust that follows this amazing game, that both is a traditional role-playing game and yet is so unique that having played dozens of traditional role-playing games for decades doesn't give one any insight into general principles. Nor am I going to discuss Vanguard's particular campaign milieu using that setting, where lack of prep doesn't cause inconsistencies, and the inconsistencies only deepen the mystery.
There is no point.
What I am going to do is disentangle two threads that Vanguard is trying to weave into one: namely, planned vs. improvised play on the one hand, and shared world-building on the other. And then, barring more input that isn't part of the same circular argument, I am done with being derailed for a bit.
Planned vs. Improvised Play
Every GM needs to improvise. It is impossible to prep a game so completely that all contingencies are accounted for. Even were you able to do so, the odds are good that your game would lose a spark of vitality by so doing. Having to come up with answers in the moment is a spur to creativity.
BUT...If you put 100 prospective GMs in a room, and made them all create material on the fly, and also create material using some method of actual prep (brainstorming ideas, refining, and then actually going to the effort of writing them down), at least 95 of those GMs will have done better with prep, and at least 95% of the prepped work will be better than the aggregate of the on-the-fly work. This assumes only a single scenario - the advantages of prepwork become more dominant as scenario compounds on scenario, and a campaign milieu is more fully realized.
This is because of several factors.
(1) Human brains are lazy. We have default answers. If we don't force them to do more, they will come up with the same or similar material repeatedly.
(2) Human brains are slow. Those easy answers come a lot quicker than harder (and often times, more interesting) answers. The game is played in real time. The odds are good that the easy answers will predominate.
(3) Human brains are forgetful. When you bother to write out your material ahead of time, not only can you see connections that you might otherwise have missed, not only can you ensure that you add appropriate "footprints" to the elements that you add to a scenario, but you have something to refer to which can aid your memory of what has gone before. You might not remember that the Duke of Duck had a limp; that doesn't mean that your players won't.
Factors (1) and (2) mean that on-the-fly material tends to be less inspired that the material that comes from careful prepwork. Factor (3) means that logical inconsistencies also tend to arise. In terms of The Walking Dead, these three factors together explain why the abilities of the walkers seems to change from episode to episode, why the characters seem unable to think of basic ideas that would occur to anyone in the same situation (ex., Rick is waiting for people in an area with many abandoned cars. After hours of waiting, Rick runs out of gas, not having checked his fuel level earlier, and not having the good sense to siphon some gas from the many vehicles available. He then decides to abandon the vehicle rather than siphon a small amount of gas from each of the other vehicles so that they can all continue to drive.), and why Rick is apparently unaware that a prison lies within a couple of hours of his house, despite his job as Sheriff.
Making it up as you go along gave us Hitchiker's Guide to the Galaxy, so if you have had only good experiences, or you think you are Douglas Adams, by all means continue doing what you are doing. Most people, though, benefit from prepwork.
Of course, if the game milieu cannot be effectively prepped because it is going to change whenever the players make decisions, there is no point to doing the work. Otherwise, it is the "work" in prepwork that causes most people who avoid it to avoid it.
I have been doing this for a long time, in lots of places, and with lots of people. I have run games with good, minimal, and no prep. I have participated in games run by others with good, minimal, and no prep. In well over 30 years of gaming, I have never seen no prep trump minimal prep, or minimal prep trump good prep.
If your mileage varies, go with your experience instead of mine. If you want me to believe that not prepping is just as good as prepping, well, extraordinary claims require extraordinary proof, and I have yet to see any evidence at all.
Assertion is not evidence. It doesn't matter who is making the assertion. I know that I keep harping on not taking my advice if it differs from your experience, and this is why. Your mileage really may vary. Someone saying something - me, Vanguard, anyone - does not make it so.
Let us imagine three different GMs are prepping a game, and all three want their players' input on what to include. I have been all three of these GMs are different points in my gaming career.
(1) The GM is devising a city to be the hub of his DCC campaign. Let us call this city Shanthopal. He asks his players, "What would you like to include in this city?" and takes notes, but does not guarantee anything. By so doing, the GM gains an idea of what his players would like, and the players gain some idea of what may be there, but no concrete idea of what is there.
(2) The GM is preparing a 3rd Edition D&D campaign, in a region he calls the Lakelands. He invites players to devise the details of their characters' backgrounds, including information about where they may have come from, but cautions the players that what they come up will be what their characters believe to be true. It will not necessarily be true.
(3) The GM is preparing a city for a 2nd Edition AD&D campaign. Following the advice in one of the 2e books, the GM invites the players to aid in creating the city, with the understanding that what they decide to be true will be true.
In all three cases, the players began with an initial sense of excitement and ownership. In the third case, the players ended with a sense of meh as they were forced into positions where their associated game was damaged by the dissociated game they had played earlier. In short, it is less fun to "discover" vampires in the sewers if you have placed them there and are actively manoeuvring the game into that "discovery" than if there happen to be vampires in the sewers and you discover them the hard way.
It is not difficult to extrapolate to the situation where the players also choose what will and will not be allowed into the game. One of the best series of sessions that I have run was using James Raggi's Death Frost Doom, along with some time travel, and the DCC ruleset. If the hard-hitting contents of these sessions had to be vetted prior to play, the scenario would not have been interesting at all. Sometimes we want material that pushes our comfort zone. For some of us, knowing that we don't get to decide what the world is, only how we respond to it, is the point of the game. The exploration of the game milieu is in turn an exploration of ourselves, of our strengths and limitations, of our ability to deal with the unexpected or the unwanted. It is not that we want to lose, but rather that we want to know that it is always possible to lose. It is not that we want to face extremely hard choices, but to know that those choices are always out there in the wings, and that the game can turn on a dime.
By these criteria, a game of Medieval Walking Dead, where you are never confronted by the decision to either help or ignore a sorcerer being stoned, not knowing whether the walkers are due to his magic (as the mob is screaming) or not is a pale sort of game indeed. Unexpected and unintended consequences, and the need to important make choices with limited information, are, IMHO, part of a good role-playing game.
Examples (1) and (2) I would advocate. Example (3) I would not.
A Poisonous Meme
Read this quote:
For the purposes of the game, the world consists of what players encounter. Anything they do not is waiting to be discovered.This might make why I broke down the players' and the GM's game slightly more clear. From the GM's (dissociative) perspective, the world consists of that which is prepped. From the players' (associative) perspective, the world consists of what they know, what they imagine they know, and what might be. Like a quantum wave-function, it only collapses into a single possibility when it is checked.
Finally, players are limited by what they can discover by both their in-game decisions and time (as in, we play once a week for four hours).
In either approach to GMing (planned vs. improvised), the kind of things they discover are necessarily constrained. For the former, it's restricted to whatever the GM put there. For the latter, it will be something within the scope of the shared fiction.
When you're playing the dissociative game, you have every option, sure. Once play begins? No, not if you're sticking to your notes. Likewise, when we sit down to build the situation, we have every option as well. Once we play, however, we are firmly within the prison of our own making.
This is a primary function of the divide between the associative and the dissociative game, and one of the major things that the GM provides the players that they could not gain by merely making up the game milieu in turns while playing. Until the wave function collapses, the scope of the game from the associative side is wider than that from the dissociative side, and the game is so designed that some wave-functions can only collapse in the case of either (a) an event occurring within the game, or (b) the players partaking in the dissociative side of the game to at least the degree described in example (3), above.
Take our poor sorcerer being stoned as an example. The possibility is there from the associative side of the table until it occurs. That it does not occur does not take it off the table. Even its occurrence immediately opens up a new wave function that it may occur again under different circumstances. The GM need not even have considered this possibility for the wave function to exist; it exists merely because the players consider it. And players tend to put a lot of thought into the parts of the game milieu that they do not yet know, because their doing so increases the chances of their succeeding at their goals.
From this wave function arise additional wave functions. What if the mob turns on one or more PCs? What if the mob is wrong? What if the mob is right? No mob need appear in the GM's notes or in actual play for these wave functions to arise.
The associative game allows the game to be much, much larger than what is played at the table.
When you understand this, you also understand the limitations inherent in shared world-building. The more the players know about the world with certainty, the more wave functions collapse, and the more limited the associative game becomes. The poison in the the meme that "no limitation occurs" is that, if you accept it, you might find yourself trading away something without even being aware that it existed in the first place.
I should note, I'm deeply amused by one thing in this conversation. You're arguing here that on-the-fly GMing doesn't lead to a believable consistent world (which is not true), but criticiszing this approach as more akin to fiction writing. Isn't verisimilitude, which is what you're going for, part of that same equation?
This is not actually true.
I am arguing that shared world-building of the "hard" kind - example (3) rather than examples (1) or (2) - damages the associative game. I am further arguing that, if the world is being written or re-written in accordance to the players' choices or expectations in situ, then the players are no longer exploring a world; they are exploring the GM's evaluation of their choices.
The outcome/consequence of choices being based upon pre-existing conditions/context is a hallmark of role-playing games. The outcome of choices being based upon the needs of plot is a hallmark of fiction. If the writer does his prepwork, the fiction can be good fiction. Most writers who do not do their prepwork create bad fiction.
"Golly," said Sheriff Rick. "How did I forget that Federal Penitentiary was here?"
While the GM can (and IMHO should) strive for verisimilitude as part of the creation of the context and consequences of choice, no one at the table is creating a story. The story is what comes after the game, when events are distilled into story form. What is happening during the game is context-choice-consequence, repeatedly, creating a pattern of expanding and collapsing wave-functions. A story is static; the game is not. Good prepwork allows for context and consequence that rationally and consistently follow the available choices. Bad or no prepwork leads to situations where everyone thinks sorcerers caused a plague, but no mobs are out looking to lynch sorcerers.