I floated another question on twitter, since it tends to be an interesting sounding board for idea seeds, and this one's sticking. That this is profoundly connected to my previous thinking on structure will either be incredibly clear or incredibly oblique - not sure which yet.
I asked whether any RPG settings had revealed all their secrets in the initial book, and then used supplements to respond to those secrets and reveals (rather than introduce new ones). This is not quite the same thing as asking which games have no metaplot - rather, it's a structural question about how information is handled.
It is easy to find examples of RPGs that don't do this. 7th Sea, for example, has placeholders for secrets in the core book (The White Plague or Die Kreuzritter for example) which are explained in later supplements. It also has non-flagged secrets scattered across its books.
While I'm not fond of this model, I acknowledge it's practical advantages as a publisher. In short: it drives sales. People like being in the know, and this is a great way to tap that. But, thankfully, I see it a little bit less frequently these days. This is not to say we see no supplement cascades, but they're often structured a bit differently. The new World of Darkness stuff, for example, is still supplementastic, but it's more modular in its design. If you skip a book, you have a decent sense of what you're skipping.
But the question of games that have turned the model of secrets on its ear, elicited some interesting responses, as well as some surprises, and I want to flag a few that came up.
Torg - This one got mentioned a lot, and I'm going to have to ask Fred how much was revealed in the boxed set because I have no idea. I have a great conceptual love of Torg, but it's based entirely on people telling me about the game. I have never had a chance to play or read it.
Conspiracy X - Another one I haven't read, so I have no idea. Any thoughts?
Feng Shui - This is probably the single best example of what I was thinking of. The supplements for the factions introduce ideas and plot hooks, but nothing that essentially changes things as presented in the core game. Some of this was enabled by the fantastic flexibility of the setting and the general tone of the game, but there was also a decision to go in this directions which deserves credit.
Vampire: The Masquerade - My first response to this was surprise. Vampire is, after all, the poster child for the triumph of Metaplot. But thinking about it a bit, I realized that mostly came later. The core book is actually pretty open about things and there was no _necessity_ that things go in that direction. That they did was probably a good commercial decision, but it's an interesting illustration of where these things happen. To see why consider...
Armageddon - This is pretty much a placeholder for most of the games out there which came in one book with no real expectation of supplements. The setting's meaty enough that there COULD be supplements, but everything's pretty much laid out on the table from square one.
Call of Cthulhu - This is an interesting one for reasons that are very relevant to the Dresden Files - how does external source material work into the equation? CoC could be said to be complete because all the material is out there, but that might also be viewed as a bit of a cheat.
In the end, there were more good answers than I anticipated, and I'm going to have to keep them in mind as I consider how one produces a setting today.
1 - At least until Friends of the Dragon (EDIT: Whups, meant Golden Comeback), where the need to introduce cooler-than-thou NPCs started messing with things. RPG writers - your NPCs will never be cool for the things they did to the setting. You take opportunities and focus away from the people who are actually playing your game.
2 - And I never noticed this until now, but the Cthulhu crowd does not seem to vigorously reimagine cosmology the way the Amber crowd does. Curious.