The Tau are a young, humanoid and highly technologically-advanced intelligent race native to the Eastern Fringes of the Milky Way Galaxy who are fighting to expand their interstellar empire and a philosophical concept they call the Greater Good. The Tau claim to be a peaceful race when possible, asking if others will join their cause voluntarily instead of fighting. However, if their peaceful overtures are refused, the Tau may well decide to conquer a planet and add it to their growing interstellar empire for the greater good, searing the flesh from the bones of anyone who stands against their benign expansions. Tau society is divided into a number of castes, each responsible for managing a specific aspect of their society. The Tau’s central motivating ideal is that everyone in their empire regardless of their species will work for the collective betterment of everyone else, an almost mystical philosophy they call the Greater Good.
The Tau are the central figures of the Tau Empire, an interstellar polity which is composed of several different intelligent species, primarily the Kroot of Pech, the Vespid of the world of Vespid and the nomadic Nicassar, though there are now several human Tau Septs derived from conquered Imperial humans or humans who voluntarily joined the Tau Empire because they were impressed by the concept of the Greater Good. These people are known as Gue’vesa in the Tau Lexicon and they are considered amongst the most vile of Traitors and Heretics within the Imperium of Man. The Tau are a relatively young race (it has been only 6,000 Terran years since Imperial Inquisitors first noted that the Tau had only just mastered fire and the wheel), and they have evolved rapidly over the past few millennia. Unlike other young intelligent races of the galaxy, the Tau have made remarkable leaps in technology and now represent a real threat to Imperial domination in their region of the galaxy.

The Tau’s physiology is closely tied to their society, with the Tau of each caste effectively being a subspecies of the larger Tau race. This was initially a result of adaptation and evolution to suit the different environments each group of the proto-Tau species found themselves in, although interbreeding between the castes was later forbidden by the Ethereals.
The Tau are humanoid in shape, although they have hoofed feet and four-digit hands (three fingers and one thumb). Their skin is grey-blue (although this can vary in pigmentation between Tau colony worlds), rough in texture, leathery, and exudes almost no moisture. Their faces are flat, wide around the eyes, with an “I”-shaped slit running from the center of the forehead to where a human’s nose would be. Tau vision is considered slightly superior to that of humans – their visual spectrum extends a little more into the ultraviolet and infrared wavelengths. However their pupils do not dilate, giving poorer depth perception and providing slower vision focusing reflexes than humans. The olfactory organs of a Tau are inside the mouth. Physical strength and size varies between the Tau castes with the Fire Caste being the strongest of their kind, roughly the size and slightly weaker than an average baseline human because the Tau homeworld has gravity slightly weaker than that of Terra.

Only two female Tau have ever been illustrated. The first, Commander Shadowsun, appeared to have a more human face than male Tau; being smoother and sleeker with larger eyes, a nose-like facial feature and a “Y” shaped facial slit. It is not known, however, whether Shadowsun is representative of all female Tau. The second known Tau female, the subject of an Imperial dissection by the Magi of the Adeptus Mechanicus, had the facial characteristics of a male Tau.

The Tau do not possess psykers (indeed, their minds barely register in the Warp at all) and as a result have little knowledge of the Immaterium beyond its existence. This gives them some level of resistance to Warp-based powers affecting the mind, but it offers little, if any, protection against physically-manifested offensive psychic powers. They are largely unaware of the perils of the Immaterium and for this reason the Tau have conducted research into the Warp on Medusa V, however, the conclusion was reached that further research was unfeasible, and that “the Warp is no place for the Greater Good and is best left to those foolhardy races who cannot pull back from that terrible realm.” Ethereal Caste members also have a diamond-shaped bony ridge on their head. It is believed by Imperial scholars that through this organ the Ethereals exert a pheromone-based or latent psychic control over the other Tau castes to keep them focused on the Greater Good, but this is mere speculation, and no evidence of this has yet been found.

Due to their notable absence of psychic ability, the Tau have no equivalent to the Navigators of the Imperium, limiting their Warp jumps to short-distance “shallow jumps” or “Warp dives.” Their interstellar vessels therefore take much longer than Imperial vessels to traverse the vast distances between the stars, having to “skim” the surface of the Warp rather than making extended, long-distance Warp jumps directly through the heart of the Immaterium.

Tau warriors receive only limited training in the arts of close combat, usually depending on Kroot mercenaries to fight in the horrible melees so common in 41st Millennium battles. However, due to their superior range of vision in the electromagnetic spectrum and a predilection for patience, the Tau have proven themselves to be extremely efficient sharpshooters with the ranged plasma weapons they rely upon.

The Tau tend to look upon other intelligent races as backwards or misguided. Before the commencement of hostilities they almost always try to reason with their opponents and establish some kind of agreement that will make military force unnecessary. Noted exceptions to this policy are Tau battles with the Orks and the Forces of Chaos, with whom the Tau have little to no diplomatic relations. This is due to the fact that the Tau see no way to reason with them, and do not want them in their empire.


Rogue Trader: Season One bscarbeau