One of the computer games I play most often these days is Tribes: Ascend, the latest descendent of the 1998 classic Starsiege: Tribes. Great gameplay aside, the lore of the Tribes universe is fascinating. The story is derived from an even older game called Starsiege. At the end of a war between humans and cybernetic organisms called Cybrids, the humans emerged victorious and chased the Cybrid survivors deep out into space. They discovered a network of "jumpgates" not unlike Stargate's network, and rapidly expanded out into the universe. The settlers, far from the Terran Imperium, grew into large tribal civilizations entirely separate from Earth. These became known generally as the Children of Phoenix. The Empire sent a group of Imperial Knights, the Order of the Blood Eagle, to pacify these errant tribes. The conflict splinters the Children of Phoenix, but the war continues unabated. A group calling itself the Diamond Sword, knights under the tutelage of a Buddhist-like Enlightened Master, enters onto the scene and starts gaining followers. Another tribe, the Starwolf, also appears - apparently a merging of Blood Eagle and Children of Phoenix deserters. When attacks from the Empire slow and then stop, the four major tribes - Blood Eagle, Starwolf, Children of Phoenix, and Diamond Sword - escalate their conflict. Minor tribes break away from the major ones, and things just get worse from there.
If you want to read the full timeline developed for Tribes, and download some documents going into wonderful detail on the Tribes universe - including technology, cultures, even slang - go here: http://tribes.wikia.com/wiki/Backstory_timeline I'm considering approaching Hi-Rez Studios, the current holders of the intellectual property rights, to see if Silver Gryphon Games can produce a tabletop RPG based on the Tribes universe.