From the introduction:
There are two inhabited planets in the Abaris system: Aris, the third planet, and Abar, the fourth planet. This tale takes place on Abar, when the war between the two planets was just beginning.
The many similar and yet remarkably different customs on Abar and Aris are not incidental. Abar was colonized by disaffected individuals from Aris, who felt that their talents and abilities were wasted in Aris' rigid caste system. Raised as they were in a caste system, their thoughts ran on within this framework, and they developed a different caste system - based on talent and skill, rather than inheritance.
During the game, most players will assume the roles of more than one character - two groups of players thus form two "casts" of minor characters. The principle characters may be played by a single player.