When gearing up to write a fantasy or sci-fi novel (or series) there is usually a TON of prep work to be done creating either a fresh new fictional world/galaxy or layering fictional elements on top of a "real world" setting.
For a tabletop game, most of the world-building is done visually and maybe with some flavor text on cards or in the rulebook, unless the game has a heavy narrative component.
For the Living Saga project, it is both stories and games so all the world-building has to happen and it has to happen for three distinct eras - fantasy, contemporary super hero and futuristic science fiction.
The setting probably needs to have very detailed societies, people, cultures, and histories. The characters need to feel like they are products of all the socio-economic/religious/political elements that have been created and the world needs to have a sense of having evolved from past events. Many of these details may never be explicitly depicted so as not to bog the story down with details and descriptions that do not serve to push the plot forward and feed character growth. However, without a certain amount of these details the world that the characters inhabit can feel superficial and two-dimensional.
For Living Saga I am having to develop key elements of history that transpired centuries BEFORE the Living Empires stories begin, build the plot and event cycle of that fantasy saga then skip 1,000 or so years to the contemporary urban setting for Living Metropolis all while setting down all the things that happened IN BETWEEN the two. Those in-between details do not need to be fleshed out but they serve as the history for Living Metropolis as does the entirety of Living Empires plus the undefiled (to the reader/player) of the pre-history.
Then that process has to be gone through again for the 1,000 (or so) year skip between the climax and completion of Living Metropolis and the advent Living Starship. That gives a nice, if monolithic, three-part epic spanning millennia but the saga will actually likely have one final fourth part (tentatively called Living Cosmos) to wrap up ALL the elements of what's actually going on and reveal the roots of everything that we first encounter in Living Empires.
When I step back and work on the over-arching "big picture" it often feels daunting beyond measure and I frequently wonder if I've bitten off more than I can chew, but chew I will until this is all done!