Tau (Warhammer 40,000)

In the universe of Games Workshop's table-top wargame Warhammer 40,000, the Tau are an alien race, inhabiting a small but dense region of space on the eastern edge of the Milky Way Galaxy, roughly 300 light years in diameter. The Tau were first introduced to Warhammer 40,000 in late 2001, the result of Games Workshop's plan to introduce a new race to the game.

The Tau have evolved and advanced rapidly since their first encounter with the Imperium of Man in the 35th millennium, rising from a hunter-gatherer level of technology to a starfaring race in less than six thousand years. Tau society has also advanced rapidly, from warring tribes to a unified caste system working towards common goals, known by the Tau as Tau'va, The Greater Good.

As well as the five castes of the Tau, multiple alien species are incorporated into the Tau Empire; the most significant of these being the Kroot and Vespid although many other races, including the space faring Nicassar and the mercenary Tarellian Dog Soldiers are members. In addition, human mercenaries (Gue'vesa in the Tau language) are sometimes seen to be aiding the Tau as well.

The Tau were the fourth army to receive a Codex updated for Fourth Edition rules (Codex: Tau Empire - Hoare, 2006) following Space Marines, Black Templars, and Tyranids, and were followed by the Eldar and the Dark Angels ). Additional rules for the Tau appear in a Forge World Imperial Armour rules supplement (Imperial Armour Volume Three - The Taros Campaign - Kinrade, 2005).