The Adeptus Arbites are the keepers of the great book of Judgement, the legal code of the imperium, painstakingly collated over the centuries and embodying every decree passed by the high lords of terra as the millenia pass the great book grows heavier . Indeed it has long since expanded beyond the confines of being a single volume. Its most ancient decrees are written upon parchments of human skin, enscribed in unknown tounges by nameless functionaries of a forgotten age.

The Adeptus Arbites are commonly called the Judges and their organisation represents the martial arm of the priesthood - the soldiers and police of the Adeptus Terra. Although planets are mainly self- governing and self-policing this arrangement sometimes breaks down, or proves unsatisfactory for one reason or another - rebellious Commanders may be tempted to plot treason against the Imperium, or rivals may overstep the bounds of petty feud. There is still an important role for a universal law-enforcing agency, and the Judges fill that role ruthlessly. Their duties usually fall between those of the Assassins, who may be obliged to deal with a single troublemaker, and the Army, which would be called in to wage outright war. Without mercy and utterly dedicated, the Judges are feared throughout the galaxy - for they are the agents of a harsh law, where failure and incompetence are crimes, and the only punishment is death. Judges are empowered to act as judge, jury and executioner - citizens have no rights, only members of the priesthood or Inquisition could claim anything so elaborate as a trial. Judges work from their headquarters on Earth, but their very nature takes them all over human space (and beyond). Often a small Judge squad might be placed upon a planet to work with an Imperal Commander (sometimes to keep a close watch on his activities). Their uniforms are basically black leather breeches and jacket, with extra padding at the elbows, knees and shoulders - this helps to emphasise their already considerable bulk. Heavy gloves and boots protect the hands and feet, whilst the head is encased within a simplified and practical version of the helmet worn by the Adeptus Custodes. The uniform conceals an undervest of mesh armour, although some Judges may wear carapace or even powered armour instead. A cloak is worn as part of the full uniform but is often dicarded in action. Always carried and displayed prominently is the Judge's badge - his symbol of office and power. Standard weaponry comprises of either a laspistol or bolt pistol, the ammunition for which is carried around the waist.