Codex Astartes

The Codex Astartes is a set of rules. They guide us....shape us as Ultramarines...teach us how to hold duty and honor sacred above all. But how we live with those rules is the true test of a Space Marine...
-Captain Titus, Ultramarines 2nd Company

The Codex Astartes was written by Roboute Guilliman shortly after the Horus Heresy; among other things, its suggested organizational scheme split the remaining Space Marine Legions into small, manageable chunks. It also includes tactical doctrines for just about every situation, like the formidable Steel Rain. Most loyalist Space Marines follow the Codex Astartes to varying degrees. The Ultramarines and their successors follow it like holy writ, while the Space Wolves only find it useful for toilet paper.

Chapters

Under the Codex Astartes, the Space Marine legions were to be split into one thousand-strong Chapters (often already a subunit within pre-Heresy legions) composed of ten companies. The 1st Company is composed of Veterans, and are the only company in the chapter to employ Terminator armor.

The 2nd, 3rd, 4th, and 5th Companies are called Battle Companies, composed of six Tactical Squads, two Devastator Squads, and two Assault Squads. They train together, and when a Space Marine Company deploys as a single unit, it will be one of these.

The 6th, 7th, 8th, and 9th Companies are the reserve squads, and are more specialized than the first five companies. The 6th and 7th Companies are composed entirely of Tactical Marines (who specialize in using bikes and Land Speeders, respectively), the 8th Company of Assault Marines, and the 9th Company entirely of Devastator Marines.

The 10th Company is composed entirely of Scout Marines, who are eventually promoted to other companies after a certain number of years.

Of course, one thousand Marines assumes ten Companies, with ten Squads, with ten Marines, and nothing more. But, including vehicle crews, Librarians, Techmarines, Chaplains, Company Command Squads, Apothecaries, and other support personnel, it turns out that a Chapter with a full roster will have something like 1,500 Marines plus who knows how many unaugmented human serfs and Auxilia.

Marine roles

Among the tenets of the Codex, Guilliman outlined the roles of various Marines to be used in Chapters. They include the follow:

• Scout: Scout Marines are Neophyte Space Marines who are charged with scouting terrain and enemy positions. A risky job, but if they're killed, the enemy probably did the Chapter a favor by killing them so quickly.

• Devastator: Devastator Marines can be summed up in three words: Blow shit up. The purpose of the Devastator is to provide heavy weapons fire in battle, artillery strikes, and hunting tanks. Once a Scout earns his Black Carapace and Power Armor, he will be attached to a Devastator Squad, allowing him to bond with his armor while learning its strengths lugging heavy weapons around.

• Assault: Assault Marines are those who specialize in melee combat, using Chain and Power weapons alike to fuck up the enemies of the Imperium of Man. In addition, they also possess jump packs which can allow them limited flight.

• Tactical: The backbone of a Battle Company, Tactical Marines are those who are flexible in combat, relying on both ranged weapons and melee weapons in combat. Note that due to the order of the Companies, they usually have served as both Assault and Devastator Marines, so they definitely know the basics of both.

• Veteran: Veteran Marines are those who have seen through several centuries, allowing them all the cool toys in the Chapter's armory. Most chapter veterans get to wear Terminator armor, but they sometimes stay with normally-sized power armor instead, which is instead slowly turned into Artificer armor by all the bling.

Ranks

The Codex Astartes formalized and simplified the ranks among the Adeptus Astartes, eliminating some ranks like "commander" and "lieutenant", while adding some more. They include:

• Chapter Master: The grand poobah of the Chapter. He is the one who gives Marine companies their assignments, and ultimately recognizes no external authority save for the God-Emperor of Mankind.

• Captain: Captains are the commanders of Companies, overseeing their Marines from the front line instead of the back. Captains are usually promoted from the senior Sergeant in the Company. The most senior is the First Captain, who commands the Veteran 1st Company, and is often the official heir apparent to the Chapter Master. Each Company Captain also holds a Chapter-level position of authority, supervising his Chapter's fleet, vehicle pool, recruits, or territory, for example.

• Sergeant: Sergeants lead squads of four to nine other Marines. There can be anywhere from ten to twenty Sergeants in a Company.

Outside of the above mentioned battle ranks, there are other senior positions within a Chapter:

• Chief Librarian: The head of the Librarium, who assigns Librarians to assist in battlefield communications. Also test to see if battle-brothers are tainted by Chaos or not.

• Master of the Apothecarion: The head of the Apothecarion, who assigns an Apothecary to each Company. The Apothecarion in turn also takes care of the gene-seed that Chapters place such holy emphasis on, and for good reason: no gene-seed - no new recruits.

• Master of the Forge: The head of the Armoury, who assigns Techmarines to oversee maintenance of the machine-spirits of wargear.

• Master of Sanctity: The head of the Chaplaincy, and spiritual leader of the Chapter. He assigns Chaplains to the Companies to oversee the spiritual health of the Chapter.

Dubious helpfulness of the Codex

While the Codex Astartes has a few good points on how Space Marines should fight, it contains a truckload of a lot of bad points on even how an army should be. Due to Guilliman's unending paranoia over the fact that none of his brothers are possibly loyal anymore (and to cover up on how fucking useless he was during most of the Horus Heresy), he made it so that he ruined the Space Marines entirely, which in comparison is oddly prophetic to this man who worked on the Space Marine Codex and butchered it with Ultramarine fanboyism.

One fatal flaw of the Codex is the splitting up of the legions and maintaining a maximum of 1000 battle brothers at any given time, this made the Space Marines even more of a fragmented force concerned with their own agendas than a unified fighting force along with making it longer for them to rebuild and reform whenever they sustain heavy casualties after a major campaign.

The other flaw was turning each chapter into a generic army using a different name. The Codex Astartes details specifically how a Space Marine should act in every combat situation that Roboute Guilliman had encountered. While this does give Marines a good idea on how to act when they're staring down a Chaos warband or a marauding pack of Flesh Hounds, this makes them far too predictable for those who have faced the Space Marines for a long time. As Sun Tzu said, "Do not face your opponent too many times or you will reveal your art of war;", given that Guilliman expect Space Marines to be the same thing, except for their colors and whatever the scream at their enemies to be different, the enemies of man will basically be expecting the same thing again and again. Because of this an intelligent and experienced opponent with enough dakka to survive one encounter with a Codex Chapter will quickly realize how to deal with any Marine force strictly adhering to the Codex Astartes' tactics. This fault is compounded by the fact that the Codex has no information on threats encountered after Guilliman's time. The Ultramarines experienced this personally when they got their asses beaten hard when they faced the Tyranid incursion in their sector for the first time, numerous encounters with Necrons that ended hilariously poorly for them, the Ultramarines getting their asses kicked by the Tau, and when one of their Captains developed a novel set of tactics for dealing with the Tyranids (successfully), he was punished for deviating from the Codex! It should also be noted that their greatest enemy are comprised almost entirely of former Loyalists who are intimately familiar with the tactics and approaches listed within the Codex Astares, so it's a wonder the Ultramarines ever survive in combat against Renegades.

Compare this to chapters who follow their own standard operating procedures, like the Space Wolves and Black Templars, and those who do not fully embrace all of the tactical doctrines of the Codex, like the Dark Angels and Blood Angels: they and their successors have a much more extensive list of victories, and a shorter list of failures. Consider the Damocles Crusade, wherein the Ultramarines failed to beat up the Tau for years due to their unfamiliar nature, while the independent Black Templars had much better luck. As in all matters, moderation is key: Guilliman was no fool, but he was not omniscient, either.

This is precisely why Captain Titus (who was ironically an Ultramarine himself) said Matt Ward can go fuck himself with all that spiritual liege bullshit, and that Space Marines are at their best when they mix the Codex's advice with the ability to think for their own damn selves.

Worse than that, even Guilleman himself said the Codex could not supplant brains.

Boundless Amusement

Captain Titus of the Ultramarines in the recent SPESS MEHREEN game, tells young Leandros that the Codex is not always a good thing to follow literally.

The usefulness of the Codex Astartes is also a major theme in Graham McNeill's Ultramarines novel series. By the end of the series, Marneus Calgar is admitting that blindly following the Codex might be costing them in the war with M'kar and Honsou.

Codex Astartes, as according to Matt Ward

This article or section involves Matthew Ward, Spiritual Liege, who is universally-reviled on /tg/. Because this article or section covers Ward's copious amounts of derp and rage, fans of the 40K series are advised that if they proceed onward, they will see fluff and crunch violation of a level rarely seen.

The Codex Astartes was written by the greatest of Space Marines, Matt Ward Roboute Guilliman, shortly after the Horus Heresy. It includes unbeatable tactical doctrines for just about every situation. All but the most despicable of Space Marines follow the Codex Astartes as much as they can. The Ultramarines and their successors follow it like holy writ, and as a result are the best fighters in the galaxy, while the Space Wolves, the freaks of the Spare Marine factions, barely use it at all.

The Codex is flawless and infallible, and even many non-human races aspire to its word.

Bollocks.

Nay my friend, this be Heresy.