Joshua Dyal said:
It is more difficult, though, because they don't have the implied background knowledge about your campaign that they do about the real world. Also, players tend to be more accepting of these types of things. Even if everything is telling them "A is true" if you even so much as drop a hint that "B is instead true, which contradicts A" then most players will metagame out that of course B is really true, and A is a red herring, and probably do so immediately.
I certainly wasn't implying that it would be easy. But even if you set your campaign in the real world, and play Masque of the Red Death, Call of Cthullu, D20 modern, or whatever, you are going to have the same problem of player's immediately assuming every hint you drop that the orthodox history is false is proof that the orthodox history is false and probably do so immediately.
The problem isn't so much just that players know the history, but that players have learned:
a) Most radically unorthodox claims made in the real world turn out to be false, because the real world just usually doesn't work like that.
b) Most radically unorthodox claims made in the game world turn out ot be true, because it's a fantasy afterall.
The only solution to this would be to have a campaign that's rich enough in detail that you can have several competing historical/cosmological theories about the universe, at least some of which turn out to be false. Once you've suckered the players a couple times into believing the first theory that they heard, they are going to be more wary. However, even then you aren't going to be able to approach the power of unorthodox claims about reality simply because people don't have as much invested in thier character's beliefs as they do in thier real beliefs - and if that isn't true then you've got bigger problems as a DM.
It seems to me the only way to really pull that off in-game is to use an established campaign setting, like FR or a very long-used homebrew, and make secret and massive changes to the background of the setting while leaving the face of the setting itself mostly alone. As the players gradually start to see the clues that something is totally different than everything they thought they knew about it the setting, you can maybe pull off that same level of wow factor.
Well, at least some level of 'wow' factor. I don't hope to make the game as compelling as reality, just as compelling as say a good book. I mean if the writer of 'The Di Vinchi Code' can pull off that sort of historical sleight of hand, then in theory you ought to be able to do it in a game.
One thing I've always wanted to do is create a coherent explanation for the game universe which seems complete and compelling but which I've deliberately left a glaring hole in, so that, at some point in exploring the game universe the characters ask a simple philosophical question that causes them to fall off in that hole. That question could be as simple as something like, "Ok, if that's all true, where do the souls of people come from?", which has no possible answer within the tightly laid out cosmology of the game world and hense implies that thier is something drastically wrong with the cosmology.