Warhammer 40K: How Space Marines Fight – Intercessors & Marine Modernization – Prime
Today let’s talk about how Cawl changed the ways Space Marines fight and its foundations in real-life war.
Space Marines are the center of Warhammer 40,000, and represent, for their size, the most deadly fighting force in the galaxy. They operate according to the Codex Astartes; itself built on lessons and the ways Space Marines have operated since the days of the Unification Wars. As such, Classic Marines (the pre-Primaris Marines) operate within some fixed guidelines in some precise ways.
Previously we’ve looked at how the Classic, non-Primaris, Marines fought and how that was heavily based on the armies of WWII. Today lets take a look at how Belisarius Cawl changed the way they fought, leading to a military renaissance. Also, we will look at WHY they fight the way they do, and at the real-world sources, the designers drew on in creating the Primaris Space Marine way of warfare.
And Then Along Came Cawl 
For ten thousand years, the Imperium of Man teetered on the brink of annihilation, resisting by the barest of margins one calamity after the next. At the core of its resistance where the Emperor’s Angels of Death, the loyal Space Marine Chapters who held the line. Originally they were designed to fight and win the Great Crusade, under the command of the Emperor and their Primarchs. In the wake of the Horus Heresy, they were reformed to fight a new war, though their weapons and equipment we should surmise were not greatly changed. It was this, in some ways unfinished, organization that then battled on for ten millennia, slowly morphing and decaying. By the time the Great Rift opened, it was clear that the old structure of Marines was failing; for all their martial prowess, they could not halt the Tyranid swarms, nor turn back the rising tide of Chaos. The old ways had failed. 
Into this stepped Belisarius Cawl, a master of Martian secrets tasked long ago by the Primarich Guilliman to build a new breed of Space Marines, to improve on the Emperor’s own design. Cawl did this and more. He not only introduced the Primaris Marines, larger and stronger Marines that could be made with seeming ease, but also a whole host of new weapons and war gear for them to use. By doing so, he radically changed the way the Marines fight, updating them from a system based on WWII armies to one closer to how a modern 21st Century real-world army fights.
It may be fair to point out that we do not know for certain who was behind the Primaris fighting style. Certainly, Guilliman took much office credit for it, since it was his rewrite of his own Codex that put down in writing the way the Primaris Chapter operates. As such, it could well be that the fighting style of the Primaris was his brainchild. Yet this seems a bit unlikely to me.
The fighting style of the Primaris is very closely tied to their new weapons and equipment, items we must assume that Cawl developed some time during Guilliman’s absence. Given this fact, it seems unlikely that Guilliman had much say in these new weapons, and as Cawl designed a whole new arsenal of gear, it must be assumed that he had some plan for how it would be employed. Indeed, since the new Marines underwent heavy subliminal training during their period and the whole host of them emerged armed and ready to fight, it seems clear that Cawl was the main designer of their tactics. This would have been fully within Cawl’s ability to do so, since we know he gained a large about of military knowledge by absorbing the memories of Hester Aspertia Sigma-Sigma. So it fell to Cawl to remake the Marines, and do so he did.
The Intercessor Squad
At the heart of the Primaris Marine way of fighting is the Intercessor Squad, this formation is the most basic and iconic way that Primaris fight. It is not only the cornerstone of a Primaris Chapter, and the most numerous part of it, but the formation from which most others are extrapolated. The basic Intercessor Squad is a reasonably simple formation, One Sergeant and nine Marines. It is directly analogous to the Tactical Squad utilized by Classic Marines.
Unlike most Classic Marine squads, the Intercessor Squad is armed in a homogeneous manner. Each member of the Squad carries a Bolt Rifle. In addition to this primary weapon, up to two members of the squad may carry an underslung grenade launcher attached to their Bolt Rifle. In some cases, the sergeant of the squad may carry an additional specialized weapon, such as a more powerful sidearm or a melee weapon. However, this seems to be a later addition and may reflect battlefield realities rather than the original design. The squad often deploys as two five-man tactical Squads, though some Chapters chose to formally keep their squads at a five man size.
The standard-issue Bolt Rifle comes with two main variants. There is the Auto Bolt Rifle, a lighter faster firing version, similar to an SMG, and the Stalker Bolt Rifle, a heaver slower firing version similar to a sniper rifle. Based on the modular nature of the standard Bolt Rifle it seems that a rifle can be converted to any of the variants with accessories, rather than each variant being its own complete weapon system. While Intercessor Squads have access to all three weapon types and swap them out as needed, there is no evidence that they ever deploy with a mixed weapon instead opting to always use the same weapon weapons squad wise.
This set up makes the Intercessor Squad a very focused but inflexible unit. When directed against the proper target, it is extremely deadly; but it cannot engage a variety of enemies. Primarily the Intercessor Squad is designed to hold ground and combat enemy infantry in mid to short-range firefights. If equipped with Stalker Bolt Rifles the squad instead acts as long-range anti-infantry firepower, with some ability to deal with light enemy armor, at the trade off that they will be overrun by larger formations of enemy infantry.
Unlike a Tactical Squad, an Intercessor Squad cannot fight well against any enemy it faces. If faced with enemy tanks the Intercessor Squad has few options, even heavy enemy Infantry will pose a problem to them. This, in turn, makes the Intercessor Squad a poor fit for solo deployment. Whereas a Tactical Squad might deploy on a mission on its own with the hope of having a weapon equal to any task it faces an Intercessor Squad cannot say the same. This should not be seen as a weakness per se, but part of the design, since an Intercessor Squad is not designed to fight alone.
The Repulsor
The Repulsor Grav Tank is at the heart of the Marines’ new way of fighting and is arguably the most important, if overlooked, aspect of how Primaris units function. Classic Marines relied on the Rhino APC for the majority of their transportation needs. Among the Primaris this role is filled by the Repulsor, since they fill the same role the two tanks are often conflated, from a doctrinal perspective, with the Repulsor being seen simply as an up-gunned, floating, Rhino. The truth is that while the two vehicles fill the role of dedicated transport, outside of that they are radically different.
Now first we must admit that it is not totally clear how many Repulsors any given chapter has at its disposal. We have seen the complete organization of a Classic Marine Chapter laid out on several occasions, yet currently do not have the same for a Primaris Chapter. I myself did attempt to the best of my ability to figure out how one might be organized. In doing so, and in writing this article, I have had to make some assumptions on the prevalence of Repulsors.
In a Classic Chapter, each company has Rhinos as an integral part of the Company, i.e. not on loan from the Chapter Armory. They are a standard part of the Company and the Company, and Chapter as a whole has enough Rhinos to mount every Marine who could ride in one at the same time (in this case leaving out only Scouts and men in Terminator or other heavy armor that won’t fit in a Rhino). A Classic Chapter would seem to contain somewhere between eighty and ninety Rhinos.
It is my assumption that the same is true of Repulsors in Primaris Chapters. Since they serve the same role as the squad’s dedicated transport it seems plausible that each company, possibly not including the 10th Company, has a native contingent of 10 Repulsors. This would mean, and it seems to be true, that Repulsors are common and each squad has easy access to them, this makes them an integral part of the Primaris formation.
And here we see what really sets the Repulsor and the Rhino apart. The Rhino is a classic APC, it’s role is to get the squad from point A to point B. It adds mobility and some durability to a squad but does not fundamentally transform the way the squad fights, nor does it add much to the squad’s firepower. The Repulsor, on the other hand, is a dedicated Infantry Fighting Vehicle (IFV). It’s inclusion radically transforms how the Intercessor Squad operates and what it can do. It not only adds mobility on the ground but also doubles as a drop pod for the squad, allowing it to make orbital strikes. Yet it is the firepower it carries that makes it so important.
The Deadly Combo
The Repulsor/Intercessor Combo is an extremely deadly force capable of facing most obstacles. The worries that an Intercessor Squad (or Primaris in general) lack heavy weapons becomes a non-issue when you realize that they are meant to be deployed alongside a Repulsor. The heavy weapons are still there, they’ve just moved from man-portable to mounted heavy weapons. Together the mixed unit can deploy to fight on any terrain, from an orbital drop to an amphibious landing. to fast-paced maneuver warfare. The Intercessor Squad is useful for covering the flanks of the Repulsor and clearing areas that the Repulsor can’t go, such as buildings. As such the main goal of the Intercessors would be to keep enemy infantry off the Repulsor and scouting.
The Repulsor, on the other hand, carries heavy weapons to compliment the Intercessors. It can be armed with a variety of weapons but they include anti-air weapons, and heavy anti-tank weapons, filling gaps in the Intercessors load out. They can also be armed with heavy anti-infantry weapons, which is useful either to complement the Intercessors against a horde enemy or when the Repulsor is used to transport a non-Intercessor squad, such as a Hellblaster Squad.
Realistically this means that it is a mistake to look at the Intercessor Squad and the Repulsor as two different units. They are in fact two integral halves of a deadly whole. They compliment each other and together form a deadly unit, one based on real-world examples.
The Real World Source
In my previous article, I talked about how the Classic Tactical Squad was based on late war British WWII Paratrooper squads. There we could see a very direct analogy, with the British squads being equipped and fighting in a very similar manner to Tactical Squads. Like the Tactical Squad, the Intercessor Squad also seems based on a real-world military unit. In this case it is the modern British Armored Infantry Rifle Squad.
