Imperial Guard. The Human forces in a chaotic galaxy full of horrors beyond imagination.

Adeptus Astartes. Genetically engineered super humans, the space marines fight to defend the human race from aliens, heretics and mutants.

The Inquisition. A secretive organisation whose agents travel throughout the empire rooting out heretics and traitors.

Eldar. Inhabited the galaxy for millenia before the birth of man. They are a noble race that has entered into the slow decay of their civilization.

Dark Eldar. The darker corrupted cousins of the Eldar. These piratical raiders make lightning strikes against unprotected Imperial outposts to capture slaves and resources.

Tau. One of the younger races in the galaxy the Tau have entered a phase of rapid technological advancement.

Tyranid. Horrible bioengineered monsters who rapidly strip planets of their resources before moving on in search of more prey.

Necron. The ancient race is reawakening throughout the galaxy. Having given up the weakness of flesh they have become an entire race of robotic constructs.

Chaos. The dark forces of Chaos are powerful and seductive and many traitors, mutants and heretics end up falling into the evil cults of the chaos gods.