Space Marine Organisation

posted: 12th Aug, 2007 - updated: 1st Feb, 2013


Each marine Chapter is an elite warrior-monk warband. An autonomous organisation dealing with the Imperium's most extreme special operations and black-ops. It is fully supported by all the pillars (factions) that make up the Imperium including the Adeptus Mechanicus of Mars and the Adepts of Terra. These factions petition the chapters for aid in times of crisis. No faction can demand help. This is reinforced by the fact that each chapter contains everything it needs to be self-sufficient. It even has it's own Adepts of Mars known as the Tech-Marines to manufacture and maintain war gear, it's own ships so it is not reliant on the navy and it's own support war machines. Marines are ago anywhere rapid response strike force fully capable of destroys a whole world.

Chapter Organisation

Marine Chapters are Autonomous armies outside the direct control of the Imperium operating under a mandate bestowed upon this chosen 'sons'. Each marine chapter is also a complete self contained empire and controls a sector of space. Within this space it is the marine chapter, not the Imperium, that is the power. The chapter has the rights to act as an agent of the Imperium and collect tithes and enforce tolls. Their only link to the Imperium is via their Primarch and their Patriarch, the great Emperor himself. Marine chapters and their empires are allies of the Imperium, and woe betide anyone who forgets the marines exalted position within the Imperium. This position is sacrosanct,. and all marine chapters would unite to oppose any renegotiation. Therefore when we look at the chapter we are not only looking at the military force, but also the logistical civilian base that is the empire. The most famous chapter empire is Ultramar governed by the Ultramarine chapter.

World in his hand

Chapter Home Worlds

Once a world has been claimed by a chapter, and the claim approved by the High Lords of Terra, it comes under the chapters custodianship. The world is then completely separated from the usual command structures of the Imperium, and becomes an annex to the Imperium via the chapter. The world is still part of the Imperium but via the chapter, and the chapter is an autonomous army which is allied to the Imperium (Terra) and the Adeptus Mechanicus. The safety of the world from then on is the sole responsibility of the chapter.

Under a chapter rule, the marines are often portrayed as 'Demigods' (similar to old Greek myths of Hercules) due to their enhancement by the Emperor and vested with ultimate power of the state (similar to the Royal Prerogative). Though marines are quick to state they are not gods, the populations of their worlds continue to view them as such (and being secretive about the marine process doesn't help).


Each chapters is made up of 10 companies each of 100 troops. Each company is a tactical battle unit which specialises in various roles, and they can act independently or combine to form a battle group. A battle group is 2 or more companies acting together and directly supporting each other in a given war zone. Companies in the same war zone but not working directly together are referred to as companies (by number), and battle groups in the same war zone not directly supporting each other are referred to by a battle group number, often taken from highest ranking company in the battle group.


Each Marine Chapter is made up of 1000 marines. Of these 900 are divided among the 9 of the chapter's 10 companies. The remaining 100 are made up of command units, Tech-Marines, Apothecaries, Librarians, and act in support roles, leading scout units or train recruits back on their home world.


The 10th company is made up of scouts. The scouts are not counted toward the 1000 marine total as scouts are not full marines (not having received the Black Carapace implant). A chapter can have any number of scouts as long as the are lead by a full marine (which limits the size). However, depending on the chapter and their activity there can be far more than 100 scouts in the 10th company. Often the scout company will be around 120-240 strong lead by 30 vets, but in prolonged campaigns with heavy losses this can increase to many hundreds. In these cases vet may lead up to 20 scouts each (30 vets = 600 scouts). Indeed the scouts can be considered a guerilla force/ army in their own right, and some chapters like the Black Templars have hordes of scouts and neophytes in the field, with regular marines take scouts into battle (seconds and such).

Blog post on 1,ooo limit


The concept of the marines was born in the time of the great crusade, with the sole aim to reclaim lost human worlds and unite them under the Imperium. The emphasis on 'human' can not be understated in this case, and the reasoning is simple: human world that do not comply or are infested with aliens that are worth taking back by force and can not be taken down by conventional forces are probably STC compliant. The biggest hurdle for the Emperor in taking back rebel or occupied STC patterned worlds with working technology was getting around the STC designs themselves. The Emperor had seen STC designs and defences in action, and knew how powerful they would be, so he bent his mind to create tactics and strategies to overcome the STC. However regular humans simply were not up to the task and would be slaughtered. This lead to the Primarch program and the marines.

As the STC defines as set of standards of all areas of construction and to which all designs of a given category must abide, the STC does have so quirks. One of these is the dimensions of doorways within the Ecorium design and the derivative bunker complexes. All STC Ecorium cater for modular units to be easily moved and this includes some heavy equipment. All the passageways and doors in STC bunkers are much larger than regular human dwellings and therefore some heavy units can more around them with ease.

Another aspect of most small arms is that they are limited by the human wielding them. Even though the machines handled defence during the Dark Age of Technology, humans had access to a formidable arsenal of personal weapons that could be a problem in the close fighting within a STC environment. Each would have to be dealt with.

Firearms: Automatic ballistic weapons are extreme hamstrung by this and assault rifles are very difficult to control with large calibres and high velocity rounds. This limits there power. Armours developed in the later 21 century where already countering this weapons, and leaving only he harder hitting single shot rifles, such as anti-material sniper rifles with recoil suppression.

While most humans in armour could withstand a couple of impacts in late 21 century armour they would still be knocked down and the enemy could close (where mêlée weapon are highly effective, many ballistic armours are not mêlée weapon proof and often hindered grapple and wresting for the wearer with some of the bulkier designs). The wrestling exoskeletons of the Techno-barbarians of earth used to settle techno-duels of honour between corporations houses formed the basis of an idea to get around this, the idea of heavy mobile armour. While much technology had been lost these rigs endured. A warrior within a rig could withstand multiple high velocity hits and remain operational due to the extra bulk (inertia) and armour thickness.

Lasgun: An other weapon that would likely to be encountered would be the formidable Lasgun, a weapon with limited recoil and packed a punch far in excess of what a human could handle in a ballistic firearm. It also benefited from great logistics and ammo supply in the from of STC universal-engines, and with a plasma core allowed infinite recharge of the power cells. The counter with the rig concept was plenty of heavy ceramite plates to counter these lethal weapons.

Bolter: Lastly the long range Bolter. A weapon that fired gyrojet bolt that rapidly accelerate to speeds far in excess to what most anti-material .50 sniper weapons to put out. It effectively gave a regular human the hitting power of a 25mm auto-cannon are range, it's only weakness was at close range. This would not be too much of a problem within the confines of an STC environment (considering it's weakness it may be surprising that the Bolter is the weapon of choice for the marine, but this has more to do with the 'smart' ammo which far outweighs the shortcomings of the gyrojet at close range. For more on Bolt tech: Bolter).

Birth of the Elite

The concept of exo-armour derived from the Techo-barbarian design gave great missile protection and also boosted grappling power (seeing at that is what they were designed for, and a whole martial-art was already developed for their use). The early designs proved successful in the Emperors conquering of Terra where he decapitated the leadership of opposing faction by storming there corporate (STC plans) HQ. This was termed a 'hostile takeover' and 'forced management retirement' (also known as the 'golden handshake' due to the Emperors gold gauntlets) in Techno-barbarian jargon. However there where shortcomings and one of these were knock back when troops attempted to wade through heavy fire. They simply did not have the armour, bulk or speed to effectively 'own' the STC complexes and were vulnerable. These Elite while exceptional, but they would not survive a full STC complex.

What the Emperor needed was more protection for his elite forces, but the human frame was two small to simply over-power the exoskeleton and this headed towards the Dreadnought technologies with the human house within it's belly in a foetal position with their nervous system wired into the beast. This would solve the firepower resistance issue but Dreadnought were too big for STC complexes as they were 'outside' rigs.

What was needed was a larger human within the armour, with there further distance between joints allowing for much heavier armour. The problem was that large humans, of the size the Emperor needed tended to suffer from growth hormone defects an such, so he turned to science to tamper with genetics in order to lay the foundation for a warrior clan of large robust humans. The humans with upgraded armour proved more effective and were tested in a short war with Mars

The Mars Equation

The Emperor did not actually win the war with Mars. His improved warriors while great, suffered at the hands of Martian technology, and only the superior tactics of the Emperor gave their mission a chance to succeed. He used a teleport hub to beam deep into the heart of the STC Martian complex where he confronted the great oracle. It was 'she', the ghost in the machine, who recognised the Emperor (and the code he bore) as the 'Scion of Mars' and ended hostilities. The union between Terra and Mars was established.

In breaching the Martian defences the failing of his beloved élite warriors were exposed, but with the Martian alliance new technologies came to hand. Work began on a new armour type which was to yield the mark 2 crusade armour for the marines (marine as they were now in 'space'). The problem was, that by all calculation, in order to resist STC fortifications within a complex an even larger human was needed to act as a frame. This posed problems as human biology, human flesh, is limited in its performance according to the Martian scientists. As the mass dictated by their esoteric formulae a bio-mechanical biped would be too slow and recommended the artificial creations of their automated legions. The Emperor resisted, for he knew the artificial mind could not be trusted, as born out of his memories of the Iron Men. Mundane flesh was not enough. He needed something beyond the mundane. Warriors of unearthly power. He need more of 'himself'.

Legacy of absent Sons

Although the Primarchs had been lost to him, if he were ever to build an army capable of exploring the galaxy for his lost sons, he would have to tap into his bloodline. Vast stocks of genetic material remained, the component parts for the Primarchs. But without severing yet more souls from his being, these artificial creations would be soulless golems, devoid of human creativity and emotion. He need to change his elite fighters into something new; he needed to go beyond the augmentation technologies he had used to crate his elite, and tap into the Primarch seed. Thus he developed a new augmentation program, where he would meld mundane flesh with the divine. The new warriors were transformed into genetic chimera, hosting a small portion of a Primarch's essence and hence tapping the power of the Emperor. This boosted their abilities, as a small modicum of warp energy flows with their chakra, crating an army of 'angels'.

Modus Operandi

The marines are highly specialised and are primarily deigned to operate in STC environment. The are relatively inflexible in this, and while each marine is effectively an light armoured vehicle this does not change the fact that they are vulnerable in the open. Modern warfare shows that heavy armour can be taken out by infantry and marines are no different.

Block warfare

Marine armour is thick enough to resist small arms fire. Their mass is enough to counter the knock-back force of repeated hits, they are fast and agile, and dominate in enclosed STC environments. They fight in brutal close combat of the Ecorium warfare.

Their primary mission is simple: to decapitate the opposition where access is denied (and where assassins prove hard to deploy). To retake opposing human or xenos held STC compliant bunker complexes. This is the mission they were designed for and what the excel at. Often 'Terminator' units in full tactical dreadnought armour will teleport directly into key positions, take and hold these points and open access for the rest of the marines to enter the bunker complexes. Other times drop pods with pulse power field projectors punch down into shallow complexes, to take the rare surface complexes.

It should be noted that marines are not intended to take human worlds which are not STC compliant. For that there is the Imperial Guard. A marine would have trouble fitting through most doors in our modern world (only some of the larger convention centres and public building have ceilings and doors high enough to allow a marine easy transit). Marines would clear most houses as we now them with Bolts set to airburst fired through the windows, or use flame units, rather than actually entering them. That's if marines are in exceptional circumstances. Marines are vulnerable in the open and prone to loosing many of their number (as evidence by many a novel!). Modern weapons as we know them would be effective against marines, a 25mm Bushmaster will affect a marine, as will many a modern tank gun. Although marine armour in key areas is superior to many IFV armours, there are weak spots and therefore not impervious. In the open a marine role should be seen as a highly mobile single person IFV. While slow over open ground compare to a tracked vehicle, they are fast at dodging and over rough ground, and are relatively small (compared to a IFV).

to support the primary directive, their secondary missions involving recon in hostile environments is handled by the scout company, those hungry to prove their worth and be elevated to full battle brother. Loosing scouts in recon does not impact the Chapters mission, the other company's plans do not rely on the scouts. If scouts are successful the information is gathered, the more information the greater the honours. As a recon unit the Scouts do not have the same equipment as the marines and look very different. Although they can enter STC environments, there performance is similar to the original elites of the Mars assault.


The marines have a range of advanced vehicles that are exclusive to them.



Drop pod: More here.

Armoured Personnel Carrier

Rhino: Light APC (Marine's M113)

Land Raider: Heavy APC (Marine's Combat Vehicle 90 (two welded together!)


Bike: Text

Land Speeder: Text

Main Battle Tank (future version)

Thunderhawk: Text (Marine's Challenger 2) Rapid response drop ship/ 'MBT'/ heavy APC/ and attack chopper rolled into one. Here you can find some of my musings on the Thunderhawk areodynamics.

New Chapters

Although the Adeptus Mechanicus take tithes of geneseed from all the loyal Chapters of marines, they are not allowed to simply create new Chapters. The process of Chapter creation is long and drawn out due to the Chapter's unique position in the Imperium and their status as autonomous armies with a mandate direct from the Emperor!

The first step in authorising the creation of a new Chapters is to petition one of the founding Chapters to raise a new Chapter. This archaic bit of red tape goes all the way back the Great Crusade when the founding Chapters where Legions. The Legions where made up of Chapters which were subsequently separated out into the Chapters of the current Imperium.

The founding Chapters still have Legion Status (i.e. the are the first Chapter of the Legion) and complied with the wishes of the Primarch 'voluntarily' through cross Legion accords, they still retain the authority to create new Chapters from their own ranks, or authorise any of their successor Chapters to do likewise.

Once a new Chapter is founded it becomes immediately subject to the Chapter accords developed by Roboute Guilliman the Primarch of the Ultramarines and creator of the Codex by which all loyal Space Marine Chapters abide. The new Chapter is immediately severed from the progenitor Chapter on creation, and all marines assigned to the new Chapter are immediately severed with it. However they are still technically bound to the founding Chapter, that's how comes these accords apply, the new Chapter is still a 'Chapter of a Legion' which is commanded to abide by the codex by the foundering Chapter.

What a mess.

Once the new Chapter is created with a core of Marines from their progenitor Chapter, the Adeptus Mechanicus can provide the geneseed for the new Chapter. The Core of Marines are known as 'Guardians' as they retain their own geneseed of the progenitor Chapter and not the geneseed of the new Chapter.

When a Chapter is under has been authorised to provide Guardians for a successor Chapter it is allowed to grow beyond the 1,000 marine limit. Usually all Companies except the scout Company gain the provision for an extra 10 Marines. When the successor Company is founded it is severed from the progenitor, and these 'extra' 10 Marines from each Company form the core of the new Chapter and retain their positions. This gives the new Chapter roughly 90 Marines, with 10 marines in each Company except Company 10 which remain empty. The highest ranking Marine in the 1 Company becomes the new Chapter Master of the new Chapter.


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