In the table-top wargame Warhammer 40,000, the Chaos Space Marines are Space Marines who serve the Chaos Gods. They are also referred to as the Traitor Legions, primarily in background material written from the perspective of the Imperium.

Background

The background shown in both Codex: Space Marines (Haines and McNeill, 2004) and Codex: Chaos Space Marines (Chambers et al, 2002) states that the Chaos Marine Legions were part of the twenty original "First Founding" legions of Space Marines, fighting for the Imperium during the Great Crusade. Horus, the Primarch of the Luna Wolves legion (which was renamed the Sons of Horus in his honor), was corrupted by Chaos and led his legion into worship of the Chaos Gods. Eight other legions followed, for a total of nine. The betrayal of these legions led to the epic Horus Heresy.

After their defeat in the Horus Heresy, the nine legions escaped into an area of the galaxy known as the Eye of Terror, where they remain. The Sons of Horus were renamed the Black Legion by their new leader, Abaddon the Despoiler; they still bear this name. Due to the nature of Chaos and the warp, the Chaos Marines who revolted against the Emperor continue to fight against the Imperium.

Some of the Primarchs, including Horus, were killed during or shortly after the Heresy. Those who survived have since become Daemon Princes. These daemonic Primarchs no longer take much interest in the affairs of their legions or the Warhammer 40,000 universe. One notable exception to this is Angron, who personally led the first invasion of Armageddon. The closest thing to a leader the fractional Chaos Marines have is Abaddon the Despoiler. Abaddon is the only man since Horus to be able to command the loyalty of all nine Traitor Legions, and has led thirteen Black Crusades against the Imperium of Man.

Differences from Imperial Space Marines

Chaos Space Marines bear the same genetic enhancements as Imperial Space Marines, wear the same types of armor, and wield much of the same weaponry, meaning they are the equals of their Imperial counterparts. The timeline of the Warhammer 40,000 universe has advanced about 10,000 years since the Horus Heresy; the Imperium has had some technological advancement since, and has far greater access to material resources- therefore, Chaos Marines lack some of the more advanced technology employed by Imperial forces. Chaos Marines are able to make up for their lack of advanced technology by being able to include various types of daemons, and by being able to field a more veteran force, owing to the fact that Chaos Marines are virtually immortal.

Recruitment

Imperial Space Marines have ritualized methods for turning new recruits into genetically enhanced Space Marine warriors. Chaos Marines lack the same technology needed to do so, and must turn to other methods. These include enlisting the services of Fabius Bile, a Chaos Marine known for his experiments in genetic engineering; taking genetic material from other Space Marines and implanting it in new recruits (Chambers, et. al, 2002); and implanting recruits within mutant giant women where they incubate (McNeill, 2004).

Current status

Each of the Chaos Space Marine Legions fights using a different style of warfare; also, four of the nine are dedicated to one of the four major Chaos Gods. Codex: Chaos Space Marines (Chambers et al, 2002) includes the current rules for fielding a Chaos Space Marine army in a game of Warhammer 40,000; it also includes rules for fielding any of the nine specific legions.

The nine Chaos Marine Legions are:

• Black Legion
• Thousand Sons
• World Eaters
• Night Lords
• Word Bearers
• Alpha Legion
• Iron Warriors
• Death Guard
• Emperor's Children

The Lost and the Damned

There are also many humans and mutants who serve Chaos, and they are often used by the Chaos Marines to bolster their ranks. These traitors, mutants and heretics are collectively labelled the Lost and the Damned. Rules and background for these forces can be found in Codex: Eye of Terror (Chambers et al, 2003).

Post-Horus Heresy converts

Space Marines serving the Dark Gods are not exclusively represented by the nine original Traitor Legions; since the Horus Heresy, some Space Marine Chapters have been corrupted in one way or another by Chaos. Very little background information has been provided about these Chapters, and no specific rules exist for them, allowing players to adapt other rules to represent their forces. Examples include the Sons of Malice, the Damned Company of Lord Caustos, the Violators and the Astral Claws (known as the Red Corsairs since their rebellion).

References

• Chambers, Andy; Haines, Pete; Hoare, Andy; Kelly, Phil; and McNeill, Graham (2002). Warhammer 40,000 Codex: Chaos Space Marines, 2nd Edition, Nottingham: Games Workshop. ISBN 1-84154-322-5.
• Haines, Pete; and McNeill, Graham (2004). Warhammer 40,000 Codex: Space Marines, 4th Edition, Nottingham: Games Workshop. ISBN 1-84154-526-0.
• Chambers, Andy; Haines, Pete; Hoare, Andy; Kelly, Phil; and McNeill, Graham (2003). Warhammer 40,000 Codex: Eye of Terror, 1st Edition, Nottingham: Games Workshop. ISBN 1-84154-398-5.
• Abnett, Dan (2004). Eisenhorn. Nottingham: Black Library. ISBN 1-84416-156-0.
• McNeill, Graham (2004). Dead Sky, Black Sun. Nottingham: Black Library. ISBN 1-84416-148-X.
• Chaos Space Marines. Games Workshop. Retrieved on 2006-03-01.