Githzerai and Githyanki split from a common origin before the rise of Orichalan Empire. The warlike githyanki settled in the astral plane, founding a fortress-city on the corpse of a many-armed god. The githzerai retreated into far-flung monastery mind-palaces elsewhere in the astral, and erstwhile shelters in the falling-down place.
The gith races have waged war upon one another and upon the Illithid horrors for ages. During this time, they have never tried to carve out larger settlements, city-states, or empires. They do not indulge in planar politics, nor are they known to pursue divinity or outsider status.
Githyanki live as pirates and scavengers of the planes, taking what they need from others and slipping away with their spoils. They do not trade, and they rarely parley. They treat other races with scorn and derision at every opportunity. Despite this foul demeanor, they are tireless combatants, sometimes literally laughing at their own suffering.
Githzerai are exemplars of self-control, ascetics in every sense of the word. They embody the spirit of the warrior-monk, and their teachings may have even guided monks elsewhere in the cosmos. They are stern, laconic, and painfully scrupulous. They do not engage in piracy like the githyanki – indeed, they have little traffic with the outside world.
Little is known of gith history and motives, and what is known has never been confirmed by any gith. Since the astral plane and the plane of Entropy are both unsuited for raising mortal offspring (and the gith remain mortal), githkind must travel to reproduce, presumably somewhere in the material plane.
Githyanki and githzerai are inclined toward psionic activity, and develop psi-like abilities as they acquire character levels. Despite their monstrous appearance, they appear to age and reproduce much as humans do.
Individual gith might make their way into mixed adventuring parties, particularly if they have misgivings about their peoples. Even such rare estranged gith do not speak about the history and motives of their people.
Humanoid (astral native), + 2 DEX, + 2 CON, -2 WIS, darkvision 60’, naturally psionic (3pp), psi-like abilities 3/day [CHA, CL 1/2 HD] (by HD: 1: far hand, psionic daze, 3: concealing amphora, 6: psionic dimension door, 9: telekinetic thrust, psionic planeshift (1/day)), power resistance 5+HD, favored class (fighter), ECL +2
Humanoid (astral native), + 6 DEX, + 2 WIS, -2 INT, darkvision 60’, naturally psionic (2pp), psi-like abilities 3/day [CHA, CL 1/2 HD] (inertial armor, psionic daze, catfall, concussion, psionic planeshift 1/day at 11HD), power resistance 5+HD, favored class (monk), ECL +2