Codex: Space Marines is an expansion codex book for Warhammer 40,000 3rd Edition. This codex covers the most common Space Marine Chapters detailing history, equipment, organization, special rules and characters, painting schemes, and army lists.
From the back cover:
Space Marines are Humanity's ultimate warriors, dedicated to the defence of the Emperor and the Imperium of Man. Inside you will find:
Army Lists: The complete Space Marine army list, which allows you to choose your forces for a battle. Also included is information detailing all the weapons, vehicles and wargear used by Space Marines.
Hobby Section: Sixteen full colour pages packed with invaluable tips and advice on collecting, painting and playing with a Space Marine army.
Special Characters: Complete rules and background information for Space Marines characters such as Marneus Calgar, the Emperor's Champion, Captain Cortez and others.
New Scenario: Planetfall Mission - a new Space Marine mission scenario and rules for playing it.
Re-print in 1999, 2001 and 2002.