This is a repost of musing thought I had in another thread:
What about a game that has a consistent starting point, but the secrets that are discovered alter it so that the end result is like an RPG version of the child's game "Rumor". It would be kind of cool to have a talk about a game where you're discussing the game and find that each of you discovered very different truths about the same political entities and groups.
I think this idea has an appeal to my way of thinking. Now, a twist I just thought of is - what if you could join another game in process at another group with the character who came from another game in progress. Two worlds that started from a single starting point that went in differing directions and are now joined by some sort of probabilistic travel.
This would make a cool campaign idea (or even a cool game idea) where characters can move from world to world (all having the same starting point), but moving at different time flows (some groups play more often than others, some groups blue book great deals of time, etc) and with very different results. Even the mixing of the travelers would create wrinkles and motes.