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
‘But your teachings…’ ‘Are yet flawed,’ said Guilliman. ‘No one, not even one such as I, can anticipate every possible outcome of battle. My words are not some holy writ that must be obeyed. There must always be room for personal initiative on the battlefield. You and I both know how one spark of heroism can turn the tide of battle. That knowledge and personal experience can only be earned in blood, and the leader in the field must always be the ultimate arbiter of what course of action should be followed.’
-Roboute Guilliman, Primarch of the Ultramarines
"Is that wise, captain? The Codex Astartes does not support this action-"
-Leandros

The Codex Astartes was written by Roboute Guilliman over the course of the Horus Heresy and presented it when things settled down; 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 some pre-Heresy legions like the Blood Angels, Dark Angels(heh), Salamanders, Ultramarines, and Word Bearers) 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 called Reserve Companies, 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, Honor Guard, Dreadnoughts and other support personnel, it turns out that a Chapter with a full roster will have something like 1500 Marines, not counting a scout company that doesn't have a fixed limit of 100 scouts so attrition doesn't put a hamper on chapter reinforcements, plus who knows how many unaugmented human serfs and Auxilia. It's also a figure which assumes no battle casualties; given that the mandate of the Space Marines is to seek out and destroy the direst enemies of the Imperium, this is a state of affairs which is hardly ever the case - indeed, one of the reasons Reserve Companies exist is to provide a pool from which to keep the Battle Companies at fighting strength.

Marine roles

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

• Scout Squad: Scout Marines are Neophyte Space Marines who are charged with scouting terrain and enemy positions. A risky job, but this has the effect of ensuring that the more cautious ones survive while the reckless and foolish are weeded out.

• 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 by 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. This is the next stop in a new Marine's career, helping to familiarize him with any weapons he hasn't used yet, and putting him through the crushing psychological stress of hand-to-hand combat under something resembling optimal conditions.

• 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, granting the majority of the chapter great theoretical tactical flexibility.

• Veteran: Veteran Marines are those who have seen through several centuries, allowing them access to all the cool toys in the Chapter's armory since they're hopefully experienced and cool-headed enough not to, say, super-glue the sacred sword of the Founder to the codpiece of their armor and pretend that it's their willy. Chapter veterans get to wear Terminator armor (the Crux Terminatus is a cross between a medal and authorization papers), but they sometimes stay with normally-sized power armor instead, which is instead slowly turned into Artificer armor by all the bling and enhancements. Power-armored Veterans are divided into two subgroups: Vanguard (who focus on close quarters combat) and Sternguard (who focus on bolter drills and other forms of ranged warfare).

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. That being said, it's a very silly (or very manly) Chapter Master that can tell an Inquisitor to sit on a Nova Cannon and rotate. Whilst Inquisitors are technically outside the Space Marine chain of command, they have the ability to requisition squads, Companies or entire Chapters if need be.

• 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 depending on the influx of recruits. There are approximately ten sergeants per Codex approved Company. Often, the most senior sergeant will be the commander of a company's "First Squad" (usually a Tactical Squad) and will likely be next in line for a promotion if the Captain is ever slain, but not always. Members of the Captain's Command Squad may also be Sergeants who get additional duties as the Captain's role might require.
  • Veteran-Sergeant: Not a "rank" exactly, but more of a recognition of status for those who have been members of a Chapter's First Company, quite frequently these guys get redistributed back to the lower companies to act as squad leaders where their experience will do some good, hence "Veteran Sergeant". These guys will usually get to wear the "Crux Terminatus" even when in power armour, to represent the fact that they have earned the right to use Terminator Armour. Note that Veteran Sergeants can serve in the ranks of the Scouts, Devastators, and Assault Marines despite being technically overqualified, in each case helping the new recruits to adapt to Chapter life. In old 3rd Edition rules you could get Captains without terminator honours, which kind of implied that they never passed through the first company but still got command, nowadays a Captain is just one thing.
  • Old second edition fluff also gave us the "Veteran" position within regular Battle-Company squads who was marked with a different form of insignia, but was wholly unconnected with the first company. His job to act as the second-in-command under his sergeant (Veteran Sergeant or otherwise) of his squad and to take command of a combat squad when the unit gets split up. Essentially this was just an organisational position and made no difference to the skill or rules of the model.

• Champion: The best close quarters fighter in a company, the Company Champion is charged with protection of the Captain from all hostile threats. Given that your average Captain is a badass in power armor, this may seem redundant, but it's supposed to allow him to focus on coordinating the battle. Almost always part of a Command Squad. The most elite of these is the Chapter Champion, who is charged with protecting the Chapter Master.

• Force Commander: Not a rank but a title given to the leader of a force (duh) either given if more than one company is fighting at the same time, or if the company has to split up and the Captain gives an XO like the leader of his command squad. For a tabletop comparison, this could be any senior sergeant since any character can be made the army's warlord and it would fit the description quite nicely.

• Honour Guard: Like a veteran-veteran, assumed to be the best of the best. These guys get bunched together and given some of the best gear available to the chapter. The fluff tells us that these guys are peers of Captains in terms of battlefield experience, but do not have the command rank to actually issue any orders, though when Honour Guard speak up it's advised that the officers nearby listen carefully. Thankfully the tabletop game is balanced not to give a whole squad full of Captain-equivalent soldiers.

• Standard Bearer: The Company Standard Bearer, given the title of Ancient (the old term for Ensign, who was traditional standard bearer), is charged with carrying and protecting the Company Standard, or banner. Also frequently joins the Command Squad. Should a Company Standard Bearer drop the banner and let it fall to the ground, he will essentially forfeit his honor. If the Standard Bearer should be killed and the banner stolen, then the entire Company will be dishonored until the banner is reclaimed. Which means that if you steal a Company Standard, you now have nearly one hundred Space Marines who were just trying to kill you, but now you had to go and make it personal. The most elite of these is the Chapter Standard Bearer (often a member of the Honour Guard), who carries the Chapter banner in war.

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 tests to see whether or not his battle-brothers are tainted by Chaos ("Yes brother, this is standard Codex procedure." *Snaps Latex gloves*)

• 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 the chapter's wargear and motor pool.

• 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.

• Reclusiarch: The Chaplain who oversees the Chapter's Reclusiam (where they keep the relics and other secret historical stuff). But quite often the job gets rolled-up into the Master of Sanctity's job description. It's uncertain what interaction (if any) they have with the Master of Relics, or it is quite possible that a Chaplain receives the role if that Captain of the 9th company gets a different position.

• Lord Admiral: Often the Captain of the 4th company gets this position by default as "Master of the Fleet", but it's not unheard of for a Captain to step down from the position if someone else would be better suited to the role, they call that person "Lord Admiral" and gets command over the Chapter's fleet assets. Though it might be perfectly reasonable that that space marine holds a battlefield rank of Battle-Brother or Sergeant, so he's probably just on secondment until the Captain (or his replacement) wants the job back.

• Lieutenant Commander: In the days of the Great Crusade, these individuals commanded battalions of five companies, outranking Captains and were subservient to Chapter Masters. We know of only one example of this rank though it is uncertain whether the title holds the same authority as before. From what we know it now applies to the commander of a vessel, which makes sense since most Space Marine chapters have more ships than Captains, so somebody has to get the job of commanding them. Though often we assume it's just a techmarine or sergeant of whichever squad gets attached to that vessel or more likely a badass high ranking Chapter Serf who doesn't need to be superhuman to understand how space ships operate.

What the Codex set out to Accomplish

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 (though the matter is highly debatable), which in comparison is oddly prophetic to this man who worked on the Space Marine Codex and butchered it with Ultramarine fanboyism.

Splitting up the Legions

One fatal flaw of the Codex is the splitting up of the legions and maintaining a maximum of 1,000 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 that can only deploy half of its forces at a given time except in the gravest emergencies. This was foolish for another reason. After all, you know the enemy matches your numbers, so you would normally wish to take advantage of the million worlds of the Imperium to outnumber your foe, right? Apparently Guilliman decided that outnumbering the enemy is for chumps. Ten thousand marines per chapter would have made far more sense, especially given the size of the Imperium and the fact that the Chapters will rarely have the option of focusing their full might on one target.

This is disputable. The original Legiones Astartes, while the most dangerous forces assembled since the War in Heaven, would have a far too centralized leadership to be effectively deployed across a galaxy-spanning Imperium with thousands of conflicts that needed Astartes support. Stress-fractures were already appearing in the established structure at the time of the Heresy. Furthermore a Battle Company or less would likely be more than enough for most campaigns.

• Except that Expeditionary Fleets and Task Forces were a thing that already existed in the Great Crusade. After all, the Legiones Astartes were already organized into chapters. They were given particular missions and most eventually developed trends of their own. An example were Perturabo's Grand Batallions, which were formations given their own missions, warzones and initial resources, and were expected to become self-sufficient and eventually increase size; this independency within a Legion's chapters is what allowed Loyal elements to secede from Traitor legions. All this allows tactical flexibility while still keeping an unified command, which is pretty much what the Dark Angels kept on doing ABSOLUTELY DIDN'T DO, FOR THE SONS OF THE LION FOLLOW THE CODEX ASTARTES TO THE LETTER. (Uh-huh, sure they do *cough* Deathwing/Ravenwing *unconvincing cough*)

But wait, you might exclaim, what about wars that DO require a Legion level deployment. Well, with the exception of the First War for Armageddon and the First Tyrannic War, Legion sized forces were present at those conflicts albeit from various Chapters but with an unified theater-exclusive command structure. Notably Dante and Logan Grimnar assumed such a role in the Second Armageddon Wars and the 13th Black Crusade respectively, in either case with the almost-unanimous consent of their fellow chapter-masters.

While the Grand/Clan/Fighting Company system of non-codex Chapters offers a greater degree of flexibility in terms of galactic force projection, it leaves the individual non-Codex Companies much more vulnerable to the debilitation of heavy casualties. As a whole though, the Codex Astartes does not structurally hamstring its adhering Chapters. The character of the Chapter does that.

It transpires that Guilliman's first intention with the codex was never to actually break up the Legions AT ALL, but saw the usefulness after discussions with one of his sergeants: Aeonid Thiel and figured out that smaller forces of marines can respond and deploy with far more efficiency than the Legions of the past, and that if larger deployments ever became necessary then the chapters would support and adapt to one another.

Codifying Conformity

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;" (Any body else find it ironic that Sun Tzu, a notoriously proverb-y text of what to do in any given situation, is invoked to denounce the Codex?) (Not really. Have you actually read the Art of War? It's a book of generalized tips for managing huge groups of people, including basics you might not think of, like "let the enemy retreat, or else they'll fight your balls off". In contrast, the Codex Astartes is very specific on how things are to be organized at all times) given that Guilliman expected Space Marines to be the same thing, except for their colors and whatever they scream at their enemies, 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 constantly got themselves outdicked and outmaneuvered by Tau, and when one of their Captains developed a novel set of tactics for successfully dealing with the Tyranids, he was punished for deviating from the Codex (OK, the reason is because he left his men to join a Deathwatch mission)!

It should also be noted that their greatest enemy are comprised almost entirely of former Loyalists millennia old veterans who are familiar with the tactics and approaches listed within the Codex Astares, so it's a wonder the Ultramarines ever survive in combat against Renegades. It's probably because Chaos Marines are all batshit insane by the time loyalist Astartes encounter them.

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 (and due to Farsight deciphering the Codex and using it to predict the actions of codex-chapters), 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.

In actual fact his original intention for the Codex Astartes was to REMOVE all of the varied and idiosyncratic legions of the past and create a single UNIFIED Legion with a more flexible doctrine. In the past, the Legions were made up of companies of soldiers who fought in the way that best suited them, thus the White Scars would be bikers, the Blood Angels would be Assault marines etc, or even within individual Legions you would have found that certain companies fought in a particular manner according to their experience, creating a stagnation in tactical flexibility. In the same conversation he had with Aeonid Thiel he realised that training your soldiers to behave in a more tactical manner was actually better, so basically that an Assault Marine could change his loadout and become a Devastator or whatever role needed filling at a particular time. (Ironic in that the Alpha Legion were the only guys doing that pre-heresy, but Guilliman would scorn Alpharius's overall strategies as being too wasteful, but that had nothing to do with an individual unit's tactical flexibility)

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. But here is what he really thinks of the Codex Astartes and Leandros

Worse than that, even Guilliman himself said the Codex could not supplant brains. Too bad he hadn't wrote it on the books cover, or at least on first page. Then again, no one, not even amongst the Ultramarines, has read the entire codex. They all have large sections but not everything (yet stupidly act on out-of-context information). Besides, it could be in the foreword or something, no one reads the foreword. Heh, "for Ward".

Do note, however, that the Codex Astartes may be like the FBI handbook in real life. On the one hand, if you know it's contents, you can figure out a counter. On the other hand, that is REALLY FREAKING HARD to do, because it was written by a military genius, who had two centuries of experience to draw upon (Sun Tzu's The Art Of War was written by a squishy human who lived only one human lifetime, and it is still referred to 2.5 millennia later), and fought enemies that are not overwhelmingly different to the enemies faced 10,000 years later (war never changes...). No rulebook is ever foolproof, hence why it cannot be taken as an overall guide, but against 99% of all enemies it is perfectly effective (we only hear about the 1% of the time where a true tactical genius takes to the field, who has the resources/information/knowledge to take advantage of any shortcomings). Rulebooks are about mathhammer. It cannot be 100%

Did it really manage that?

Despite Ward's assertion that the codex is rigidly followed, even his own shitty writing admits that most of the Ultramarines successors/codex chapters are just picking and choosing the bits they like from the codex and ignoring the rest. And you can pretty much guarantee that any chapter that gets it's own novel is going to deviate from the codex. Notable examples are the Silver Skulls, who have combo librarian/chaplains, a scout hardwired into a strike cruiser in a similar fashion to a dreadnought (yes, it's tech heresy; yes, they know it; no, they don't care) and assault squads in the 9th (devastator) company. Also the Hawk Lords who are so into flying that other chapters send their pilots to the Hawk Lords "Talon Wings" for training, the Aurora Chapter who are treadheads above all, the Exorcists with 2 extra scout companies (12 companies total), the Mortifactors whose chapter rituals are so far from codex as to be offensive to a visiting Ultramarine and the Relictors using chaos weapons against chaos.

All Ultramarines successors, all codex chapters, all just using the bits they feel like. Dammit Ward, you can't even keep your fluff-rape consistent. It's very obvious that contrary to Ward's writing in Codex: Space Marines that pretty much nobody follows the Codex Astartes rigidly apart from some of the Ultramarines. The Imperial Fists, Salamanders, Raven Guard, White Scars and Iron Hands are also theoretically Codex chapters with varying degrees of divergence from the Codex, tweaking and modifying it to suit their favoured tactics, organisation, rituals and markings. The list of official codex chapters that diverge from the Codex Astartes is so long its just easier to list the chapters that do follow it rigidly. In that category, we have the Ultramarines and... um... well, nobody else really. Oh wait, scratch that, Ultramarines do now have non-Codex formations, such as Tyranic war veterans, so even they cannot hold the title of rigid Codex followers. That role has since been picked up by the Red Scorpions. Except that the Red Scorpions have the non-codex compliant Apothecary-Sergeant. The only Chapter that literally follows the codex to the LETTER, are the Hammers of Dorn.

Guilliman's intention was to create many smaller chapters of equally flexible forces rather than large forces that adhere to a rigid and imbalanced doctrine. Thus it's either a case that the less hidebound chapters who loosely adhere to the codex and make practical adjustments to suit their levels of experience and available equipment are more in tune with the spirit of the codex than anyone else and that those who follow the codex "rigidly" have missed the point... Either that or the deviants have failed to realise that the Codex "should" have already covered their situational needs in the first place and that deviation from it was unnecessary. It depends on what YOU as the reader think the codex actually encompasses...

Of course it should be noted that GW has never really shown what's in the Codex and writers have different views. For example, Dan Abnett views it similar to The Art of War, with general tips and tactics, while Graham McNeill views it like a football play book. Since all of Ward's codex quotes seem to favor Abnett's ideal of what the Codex is like, its possible that by following it "rigidly" its following the basic ideal of the codex, i.e. the general organization and being flexible in combat (which is why the smurfs can choose to fail morale tests when they're making tactical withdraws). It's a stupid way to word it but that's the norm for the Imperium.

Boundless Amusement

Captain Titus of the Ultramarines in the recent SPEHSS 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. When Uriel Ventris is on trial for violating the Codex, First Captain Severus Agemman comes and confides in him, saying that while his decisions made sense, the Ultramarines must stick to the letter and spirit of the Codex, as the Codex Astartes is not how to be a good Space Marine, it's about how to be a loyal Space Marine. This makes a lot of sense in hindsight, as the Imperium of Man's average response to free thinking is to start screaming incoherently and beat the free thinker to death, but we digress. 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, who in particular knows how the Ultramarines will react due to their adherence to the Codex.

Which is the exact same lesson they learn during the first Tyranid war. Which is why so many people turned on McNeill after Chapter's Due as it sums up as "Ultramarines can only be cool if they act like Space Wolves". This combine with more recent portrayals of Ultrmarines showing them as extremely tactical flexible. And the codex itself is portrayed as not a static thing but something that has been revised and added to over the years.

Nick Kyme also plays with it a bit, however far differently. Unlike McNeill who uses it as a strawman to make Uriel look cool. He treats is more or less like everyone else does. However many Ultramarines follow it differently. Cato Sicarius plays it more loosely, resulting in him being more unpredictable but also more willing to take high risk, high reward actions, and his own personality means he'll do things the codex speaks against like trying to hunt down and kill the enemy commander in a duel. Agemman meanwhile follows it more to the letter, but also follows the more willing to take pragmatic tactics because of it.

"Codex" Chapters with doctrinal variations (aka: Quirky Chapters that still are close to the spirit of the Codex)

More commonly, are those chapters which follow the codex at an organisational level, but disregard certain tactical aspects contained within, most likely because they have their own modus-operandi that they have a preference for, or because they create their own unique tactics that had never been considered.

Aurora Chapter

• Follows the Codex Astartes, yet has a large number of vehicles.
• They have a lot of vehicles.
• For a 1000 man sized Chapter, they have a lot of tanks.
• Of all the Codex Chapters they have the most tanks.
• Their armored spearhead attacks are pretty devastating.

Charnel Guard

• Cannot say too much about those guys since they are very secretive, thus their organisation and structure are completely unknown.
• Rumored to be Blood Angels successors, yet as said before, they are totally unknown from a organisational and structural P.O.V.
• Have a lot of Great Crusade and Horus Heresy Era stuff, including a Fellblade.

Crimson Fists

• More tactically oriented Imperial Fists.
• Actually do follow the Codex more closely than other Sons of Dorn (but not that much like the Hammers of Dorn).
• At the time of their founding, they were known to be the most level-headed members of the Imperial Fists Legion, therefore took in the Codex much faster and easier.
• Only deviation is the existence of a Crusader Company that is a 1st Company that has 128 Veterans. A result of an event where they were reduced to 128 members during the Crusade of Righteous Liberation.
• Due to the whole situation with Rynn's World, the Chapter became very capable at fighting Orks.

Emperor's Shadows

• Iron Hands Successors that follow the Codex.
• Put more emphasis on projectile weapons (like Bolter Weapons) and Dreadnoughts.

Executioners

• Choose to go into close combat with the enemy.
• Heavy emphasis on their own skills and superhuman abilities enhanced with sheer Determination.

Hammers of Dorn

• Follow the Codex to the letter, yet do put more emphasis on heavy weapons and overwhelming firepower.
• No really, they follow the ABSOLUTE LETTER of the codex.
• Not even the Ultramarines(Famous for having the primarch that wrote the damn thing) follow the codex more rigidly than them.
• They probably actually read the Codex from cover to cover.

Hawk Lords

• Codex compliant, yet put large emphasis on flyers.

Minotaurs

• Instead of sending out a single company, the Minotaurs utilize mob and berserker tactics along with sending out all ten of their companies to utterly overwhelm and crush their foes.

Raptors

• Camouflage Power Armour. Technically this IS in the codex, but they're the only space marine chapter out of literally thousands that actually bothers to do it. They're also sneeki beekies, just like their Raven Guard progenitors.

Raven Guard

• Sneeki Cheeki Beekies. While they do follow the codex, their chapter made amusingly extensive use of mutants (during the Horus Heresy), and stealth tactics and guerilla warfare due to their situation.

Space Sharks/Carcharodons

• Greater emphasis on infantry and terror tactics.
• Will sneak up as close as possible to the enemy to later tear them a new one in close combat while berserking.
• May be organisationally non compliant as well, but they are quite tight lipped about it.

Storm Giants

• Codex compliant, but utilize armoured assaults, Drop Pod strikes, and heavily use Scouts to get intel before ruining someone's day.
• Due to their heavy use of Scouts, they have a larger than average 10th Company.

White Scars and some Successors

• Disproportionate emphasis put on bikes and speeders compared to heavy vehicles, still adhering to codex formation however.

Non-Codex Chapters

As mentioned, there are so many chapters in the Imperium and very few of them follow the codex absolutely to the letter. Many chapters have their own preferred mode of warfare based upon their experiences, supplies and dispositions, often they generate their own interpretations and deviations from the codex. Here follows a comparative listing of those chapters and the way in which they differ from what the codex actually prescribes.

Chapters with drastic differences in formations or composition

A rare case of deviation from the codex is when a Chapter outright ignores most or all the elements of the Codex Astartes in order to pursue their own independent take on warfare. Much larger number of battle brothers than the standard 1000 men, often unique ranks that even combine elements from other specialists, ignoring the tactics Roboute Guilliman wrote down, and even unique units that sometimes do not even have a counterpart seen among those who follow the Codex more closely or completely. As mentioned before, these Chapters are extremely rare and may very well be under Inquisitorial surveillance. Because we all know how that well ended the last time when there was much more than a thousand brothers. Then again, these Space Marine Chapters may seem to concentrate a lot of power, yet are as loyal as any other Chapter. Paranoia is a staple of the Imperium.

Astral Claws

• Pre-Red Corsairs Times: Before Lugft Huron went pants-on-heads retarded, the Chapter was known for being exceptionally stubborn with skilled Bikers and favoring lightning strikes and boarding actions while still following the Codex.
• Badab War Times:
  • Due to Huron's pants-on-heads retarded thinking, the Chapter seized the Badab Sector's industry and made it so that Bolter rounds and Rhinos were mass-produced to the point being expendable, not to mention the larger-than-standard number of marines due to them purposefully not paying their geneseed tithe.
  • Emergence of specialized units (such as the hated Corpse-Takers) and human Auxilia. Squads larger due to aforementioned not paying of the geneseed tithe.

Black Templars

• "Chapter" made up of ad-hoc crusade fleets and fighting companies, their numbers thus swelling up to six times the size of everyone else's.
• No Scout company, instead recruits are apprenticed to fully fledged battle-brothers, aka "Crusader squads".
• No Librarians.
• Doctrinal emphasis on close quarters combat.
  • Abundance of previously unsanctioned Land Raider "Crusader"s to deliver said Crusader squads to CQC. See the trend here?
• Outright deification of the Emperor (contrary to the usual, more restrained veneration other chapters profess).
  • The position of "Emperor's Champion", a Chapter Champion-esque title but of faith significance.

Grey Knights

• Due to their unique training and equipment (not to mention the intimidatingly insane shit they have to deal with), the Codex would actually hamper them instead.
• All psyker Chapter of Demon hunting marines. Nuff said.
• The infamous Dreadknight.
• When the Neophyte ends his training, he becomes a battle brother and is issued a suit of power armour and his standard wargear.
• Do not have any artillery weapons like Whirlwind Artillery Tanks or lack of certain vehicles other Chapters have.

Legion of the Damned

• Previously Codex adherent Fire Hawks (maybe, now it's uncertain if they are Fire Hawks or somebody/something completely different), now a horde of angry hellfire powered, space/time/dimension travelling, spectrerevenantdemonspacemarines.
• Utilize more powerful, but unstable early versions of existing Imperial Weapons like early Horus Heresy Era Plasma Weapons.

Space Wolves

• Ignore the codex outright. It would be easier to go their page to find out how they are organised.
• Simply put, Leman Russ wanted them to be forged in his vision instead that of Roboute Guilliman.
• Although they do however take some (KEYWORD: SOME) useful tactics from the codex because they like them, but that is only this.
• Fenrisian Wolves/Thunderwolves used by the Chapter.
• Have more than a thousand marines, yet not that much as the Black Templars.
• Longfang Veterans take place of Devastator Marines, whereas instead of having normal Scouts, the Chapter has Veteran Scouts instead.
• When the Neophyte ends his training, he becomes a battle brother and is issued a suit of power armour and his standard wargear. They are then put into the Blood or Sky Claws (the latter if they are too troublesome even by Blood Claw standards).
• In the previous editions, they had access to Leman Russ tanks (logical, since the tank was named after their Primarch).
• Wolf Priests combine both Chaplain and Apothecary roles.

Chapters with differences in formations or composition

Some chapters have taken the idea of a "Chapter" and tweaked it with their own unique spin on its organization, either by adding units or ranks that aren't found anywhere else, or have their own composition of companies that doesn't fit with the approved codex model. In some cases they may ignore the codex altogether and do their own thing.

Black Dragons

• Dragon Claw squads, made up of mutants who make use of adamantium coated wrist blades.

Blood Ravens

• Pre-Aurelian Crusade:
  • Usually, the Chapter Master was the Chief Librarian too, like Azariah Kyras. This tradition of Chapter Master/Librarian combo started with Azariah Vidya (as in Vidya Games).
  • Their gene seed causes them to have an above average number of Librarians, so many they can field two whole squads of them in the First Company. Librarians are so recurrent among Blood Ravens that it's not uncommon for one to be even a Captain.
  • Actually Codex Compliant in structure, yet utilize their Librarians to scry and predict the movements of their enemies (so their Scouts are Librarians too?) and use the intel to formulate a counter strategy (because they appeared in Dawn of War, their way of war is an emulation of how RTS gamers play when they are serious).
  • Non-standard patterns of speech, incidents of hairesy, compulsive kleptomany and emphasis on devastating, defensive deepstrikes.
• Post-Aurelian Crusade:
  • With Gabriel Angelos, a non-psyker, taking the position of Chapter Master they returned to a more codex-compliant organization, albeit severely undermanned.

Blood Angels and Successors

• Scouts graduate to Assault Squads rather than to Devastator squads.
• The use of non-standard tech, like Baal Predators, Furioso and Librarian Dreadnoughts.
• Sanguinary Priests (Apothecaries) make up part of the chapter priesthood equivalent to Chaplains, who are busy tending to...
• ...The Death Company.

Dark Angels and Successors

• The Deathwing & Ravenwing instead of First and Second companies.
• Inner Circle in place of usual chapter command structure.
• Chaplains taking the additional role of Interrogators.
• Battle Companies incorporate an additional squad of veteran marines.
• Some nifty STC that they do not share with anybody apart of their own successors.

Exorcists

• Have two additional scout companies to account for the high attrition rate amongst recruits.
• ...said attrition rate being caused by subjecting recruits to daemonic possession.

Iron Hands

• Have a Chapter Council instead of a fixed Chapter Master, though a leader may be nominated.
• Chaplain Techmarines, aka "Iron Fathers".
  • The current leader is thus a Chapter Master Chaplain Techmarine. And people say the Blood Ravens are the crazy ones.
• Terminator Armour was distributed to squad sergeants instead of being reserved only for the First company.
• Pre-6th Edition fluff indicated that individual companies (clans) had their own veterans and recruits, newer fluff put them more in line with the Codex.

Iron Snakes

• Instead of having five regular battle companies and five reserve companies, the Iron Snakes have ten battle companies with an equal number of veterans, regulars and neophytes for perfect balance.
• Each squad has a Apothecary, personal Squad Standard Bearer and a number of specialists of their own.

Red Scorpions

• Apothecaries act in squad command roles instead of sergeants.

Salamanders

• Have seven oversized companies instead of ten, but otherwise broadly conform to the codex.

Star Phantoms

• Each company takes a Devastator Squad over a Tactical Squad, leaving five Tactical and three Devastators in the battle companies
• The chapter is never at full strength, seldom even at half, but maintains weapons as though they were. Their "tactical" reserve companies can fill in for full devastator squads, if needed.

Storm Wardens

• Tempest Blades being a non-codex formation.
• Heavy emphasis on mechanized warfare and mano-a-mano honorable duels to the death.

Ultramarines

• Tyrannic War Veterans are a non-codex formation.

White Consuls

• Have two Chapter Masters instead of one

Purpose for Gamers

Of course, there's a reason Games Workshop included the Codex Astartes in their fluff (long before Matt Ward came along, by the way). Basically, it makes it easier for players to invent their own Chapters.

Players who just have an idea for a cool color scheme or name but don't want to put any effort into making up a whole organizational layout can just make a Chapter that rigidly follows the Codex, like the Ultramarines. Those who want to have one or two unique organizational or tactical features can make a Chapter that generally follows the Codex but has some variances, like...well, most of them (see above). And players that want to make up entirely independent structures themselves can make Chapters that ignore the Codex entirely, like the Space Wolves or the Black Templars.

This means that Matt Ward's Codex worship isn't just lame, but actually bad for GW's business: By telling players that only Codex Chapters are any good, he's discouraging players with their own ideas from investing in models, paints, tournaments, and maybe even later editions of the game. Truly, there is no end to his failure.

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 (<< implying not killing xenos).

Bollocks.

Nay my friend, this be Heresy.