I'm in the middle of writing the Bible, the set of facts about the history of the planet that should not be changed, though adding and expanding them is good the idea that any thing that brings that story arc to this point where we are playing can be changed is a NO.
With out the story arc nothing else will make sense so I'm writing that, its quiet a large book, with some interesting characters, and no one working outside of this project will get to see it, which is a shame, but it does give backgrounds for the system to progress through.
So we have a system, we have planets, we have groups of individuals, and we have characters and laws.
Some aliens, and generally a large deal of maps and back grounds.
So getting there.
I'm doing all this on the grounds of if it does work and sells and so on then I would like the game to play through and have continuity which I find a lot of systems seem to lose now a days, though got to admit one man working on it means its only me I can blame.