The War of the Five Houses:
The idea for this came from a discussion with SJ about the Play by Committee 2 game. In that, a single empire was split internally into five �houses� all controlled by separate players. This got me thinking of a way to approximate this in a PBW game.
This will be a 5 player PBW game set in a large quadrant. All five players will start with 5 homeworlds located near the center of the quadrant (not in the same system though). The quadrant will be populated with numerous AI races surrounding you, also starting with five planets each. You will all start the game with contact with and knowledge of the locations of the other four human players, but not the AI. At the beginning of the game, each player will abandon 4 of his or her five starting homewolrds and the game will proceed from there as normal. The exact mechanics of this have not been exactly determined, but it will probably involve the first couple turns being controlled by the game owner.
The idea here is NOT that this is a cooperative players versus AI game, although during the early game survival will probably require some level of cooperation as each AI player will start out at five times your strength individually. As the ultimate goal will be the reunification of the five houses under your leadership, you will at some point need to go to war with each other. Exactly when and how this happens will be up to you.
For role-play purposes there will be a couple rules regarding setup that must be followed. The houses have been in contact but living as separate socio-political entities on different worlds for many many generations. While they originated on the same world long ago and are of the same race, their cultural differences are real and deeply rooted. All five players must use some sort of human looking race. As humans, all five players� races will also be setup as Rock/Oxygen races. There will be no ancient races, no mechanoids and no emotionless races. Beyond that you are free to manipulate your empire characteristics and racial traits as you like as this could reasonably be explained due to differences in culture between and selective breeding within the houses. You are free to come up with any sort of description and history for your race, as long as you leave the history sufficiently vague as to not conflict with the other players. The exact location of the original human homeworld is lost in the mists of time. It may be one of your five worlds, or it may be another world altogether. Feel free to be creative with that aspect. Keep in mind what you are writing is the truth as your house sees it, but not necessarily the factual historical record.
Also, since the populations of all five empires will be basically cousins and the object of the game is the reunification of, not the destruction, of the five houses, planetary glassing of the other human players colonies and homeworld is heavily discouraged. Of course in war there are unavoidable collateral damages, so there won�t be explicit penalties defined for loss of civilian life, but you can expect to lose some mojo because of it. On the other hand, you are free to treat the alien AI population as you see fit.