Many years ago I played in a game where we were given the basics of the magic system, the technolagy of the age, and a very vag turain map.
We were the learders of villages. We each got to clam a piece of the plato in the midle of the map. we role played out how our villages got along and how we interacted with the pots cities to the East and the jungle comunities to the south. To the West was a vast Dessert that would spit out a trade carravan every few years from some far off lands. Now to the North there were these black towers that started to apear. In a few weeks of ingame time more were spoted closer and closer. The Magic system used elemental spirits captured by places of focused elemental energy. when you released the elemental from its confinement it did you a faver like a geiny wish limited to what the elemintal could do. So as the towers incroched on our plato we sent earth spirts to knock them down. The power of the towers made the defending earth spirits stronger and in short order the plato was over run by these towers and the spirts commanded by the owners of the towers were imposably strong. I was a hope less task to stop them once the towers had gained infulance over the whole plato the game secion came to an end with "And that is what has been going on in the world. Do we want to be refugies fleaing to the jungle comunities. Do we want to be freedom fighter on the plato? ... " We went with the venture off into the dessert. I felt I undersood where my charactor was coming from and enjoyed helping build the world history that molded my charactor and we could always reset and be freedom fighters or take our chances at sea. or warn the jugle comunities of the imposing Towers headed their way.
I would like to try GM'ing this technic on a Space Opera Campain leting each player be a galactic federation and letting them roleplay out the history of the univers