"Beware, the Alien, the Mutant, the Heretic." - Thought of the day

in the countless battlefronts of the Imperium of man, one can find a wide variety of enemies, each one more vile than the last. The inhuman and hated Aliens, the barely toleted and abberant Mutants, and the most vile and disgusting Heretics. These are three general and broadest categories of the many myriad enemies of the God-Emperor and his imperium.

The Codex Advorsarius is The Primer to help you know the differences and identify the myriad enemies of the Imperium, divided into three categories based on their relations to humanity: Aliens, Mutants, and Heretics.

four-armed purple alien creature.

Alien

Xenos. The most common and varied among the enemies of Man. This foul creatures came to being outside the embrace of Holy Terra, and are deviants as a result. These aliens envy the prosperity and power of the Imperium of Man, and thus seek to undermine it.

massive mutated human

Mutant

Though they are descended of human ancestors, their abberant forms goes against the holy designs of the God-Emperor and tain the holy image of mankind. They are barely tolerated in the Imperium, and any deviancy is to be punished severely.

Heretic soldiers in a blasted hellscape

Heretic

the worst of them all. These vile traitors turned their backs on the Empeor and his imperium, betraying all that is good and holy, and sold their souls to the foul demons of Chaos.