This is the codex for the 5th edition rules of Warhammer 40,000.

The Space Marines of the Adeptus Astartes are Humanity's ultimate warriors, dedicated to the defense of the Emperor and the Imperium of Man. They are barely human at all, but superhuman, having been made superior, in all respects, to a normal man by a harsh regime of genetic modification, psycho-conditioning and rigorous training. Organized into small independent armies called Chapters, their unswerving loyalty is to the Emperor of Mankind and no other.

This 144-page Warhammer 40,000 Codex contains all the rules you'll need to field a Space Marine army, as well as detailed background information, bestiary, accompanying artwork and 'Eavy Metal showcase.