The Apostasy Gambit
The Adeptus Arbites is the Imperial Adepta that serves as the galactic police force of the h1. Your title here…Imperium of Man, responsible for enforcing Imperial Law (the Lex Imperialis) on all Imperial-controlled worlds. They have been granted the right by the High Lords of Terra to serve as judge, jury and executioner to any Imperial citizen they discover having broken Imperial law and the concept of due process is not one that generally applies in the Imperium. However, in those cases where Imperial law is unclear or the law breaker has committed a truly heinous deed or is of unusually high-ranking stature, the offended will be taken back to an Arbites Precinct House for judgement by an Arbites Judge, the sentence to be carried out immediately. Imperial justice is swift and sure, but not always just.
Throughout the millions of worlds of the Imperium, crime is rife. Not just the petty crimes of individuals for personal gain, but organised crime on a scale never even considered in humanity’s past. Entire sub-sectors and planets have been in the thrall of illegal cartels and criminal organisations. There are even wayward Planetary Governors who shun the Imperium and treat the dominion as their own paltry fiefdom, claiming the planet’s natural resources, labour and riches for their own. In these dire situations it falls to the Adeptus Arbites to defend the Imperium’s rights and prevent whole sub-sectors going rogue for generations, or even permanently. The Adeptus Arbites is not a galactic police force; it has little interest in petty crimes such as theft, murder or tax evasion, for these fall under the responsibility of the local planetary forces. The Adeptus Arbites is there to keep order on a far greater scale, to root out corruption, maintain the Imperial tithe and to guard against witchery.