“They live there in that great plascrete tower surrounded by walls and razor wire, only emerging to seize some unfortunate who has transgressed against the Imperial Laws or to patrol the city to prove that it belongs to them. There are crystal lenses and sound wave detectors on that tower that can watch citizens and listen to their conversations 100 leagues away, Imperial spy satellites watch what they can’t see directly and even the Governor fears them. They aren’t from here and have nothing to do with us, no more than Orks or Eldar, if they have families or children we don’t know about them and we don’t care. They wouldn’t so much as buy a glowbulb from us and we would not sell it to them. It’s ironic that they have the rather benevolent title of Arbitrators.”

Vorkas Zolowski prior to his arrest for pernicious sedition against the Emperor of Mankind.

The Adeptus Arbites are the conspicuous and ever-watchful long arm of the Emperor’s law. From their Fortress Precincts upon almost every world of the Imperium, they administer the harsh justice as laid down by the Dictates Imperialis. None are above, or indeed below, their notice, and they will stop at nothing to ensure wrong-doers are punished for even the smallest crime.

The men and women of the Adeptus Arbites are recruited from Schola Progenium facilities all over the Imperium. It takes a very special individual to be selected, and it is often those who have risen to dominate their fellow progenia through force of will or brute strength who prove ideal for the role. The Arbites must be harsh in the execution of their duty, and mercy is a weakness unbecoming of an officer of the Emperor’s Law.

Unlike the individuals in the service of the Holy Orders of the Emperor’s Inquisition, the Proctors, Arbitrators and Judges are not free to administer judgement as and how they see fit. They are instead bound by the Dictates Imperialis. This is a prodigious body of laws, rulings, precedents and more compiled over ten millennia, and ranging from the words of the Emperor Himself from the days he walked amongst men, to the most recent proclamations of the High Lords of Terra. By its very nature, this body of law is vast, and many servants of the Arbites spend their entire lifetime researching a particular point of law so that a criminal may be brought to justice.

The Arbites administer the galaxy-wide laws of the Dictates Imperialis with ruthless efficiency. Though there are many other local law enforcement bodies on every world, it is the Adeptus Arbites that enact the definitive word of the law, above all others.

Arbites Precincts are present in most every major city ruled by the Imperium. They are huge, threatening buildings that dominate and inspire fear and paranoia for many miles around. The officers of the Arbites are utterly incorruptible, and never serve on or near their homeworld: the law is their life and they are utterly and ruthlessly dedicated to it.

Arbites Precincts are often the first line of defence against the corruption of an Imperial world. The Arbites owe no direct allegiance to the world’s Imperial Commander, and so are free to react to the slightest hint of treachery. Many governors resent this autonomy, but are later thankful for it when rebels attack their palaces and the Arbites are the only force able to stand against them.

On many occasions, the Arbites Fortress Precincts have held out against full-scale invasion for many weeks, acting as a rallying point for the defenders when all else seems lost. Often, it is the Arbites’ Astropaths who get out the crucial plea for aid, to which surrounding systems respond. By the time a response is mustered the Fortress Precinct will most likely have fallen, but the Arbites will have sold their lives dearly, and will have ultimately succeeded in bringing down retribution upon the heads of those who would defile the Emperor’s Domains.

On occasion, an officer of the Adeptus Arbites may find that his line of enquiry leads his path to cross with that of an Inquisitor. What appears a criminal enterprise may manifest itself as a heretical cult; traffic in illicit goods may turn up an exclusive trade in highly illegal xeno-tech. When the particular skills of the Arbites are matched to the limitless mandate of the Inquisition, the enemies of Mankind will find nowhere to hide from the blinding light of justice.