We may earn money or products from the companies mentioned in this post.

The Imperium of Man is, as the name would suggest, everything that is under the purview of the Emperor of Mankind. The Space Marines are part of the Imperium of Man, but we’ve separated them from this list as they’re kind of their own thing. And it’s important to know that when you’re getting started with the Imperium of Man–indeed, when you’re getting started with Warhammer 40k itself–that everyone fights everyone. There are no “good guys” in the Warhammer 40k universe, and even the best of the Armies of the Imperium are essentially war criminals. Such is the nature of a game where in the grim darkness of the 41st millennium, there is only war.

Consequently, you’re just as likely to see armies of the Imperium fighting between each other, or against the Space Marines, as you are to see the Armies of the Imperium fighting the Xenos or Chaos.

The Armies of the Imperium are incredibly varied, ranging from the very unskilled Imperial Guard to the superhumans of all superhumans, the Adeptus Custodes. Anyone who is willing to fight for the Emperor is part of the Armies of the Imperium.

The Astra Militarum (Imperial Guard)

What Are the Astra Militarum?

The Astra Militarum are also known as the Imperial Guard (they were called the Imperial Guard for the majority of Warhammer 40k’s existence until Games Workshop decided to make the name more easy to copyright). They are the human grunts, the millions of soldiers fighting across millions of worlds. As such, the Imperial Guard can look like and act like virtually anything (here is an article about 11 of the most popular Imperial Guard regiments). But there are only a few Imperial Guard regiments that are actually sold: the Cadians, who are the bog-standard troops that are most widely available; the Catachans, who are jungle fighters obviously inspired by the soldiers from Predator; and the Death Korps of Krieg, who had previously only been sold as expensive resin through Forge World until they became available as plastic kits referred to as “Veteran Guardsmen”.

The Imperial Guard had been exclusively male for almost all of the lifespan of Warhammer 40k until Games Workshop released a new upgrade sprue for the Cadians in 2021 that gave female heads to the Cadian soldiers.

The Imperial Guard, as with many Armies of the Imperium, are a very shooty army, very poor in close combat, and rely on their guns and especially on their heavy weapons–including tanks–to do the bulk of their offense. When the enemy does come close enough to engage in hand-to-hand combat, the Imperial Guard rely on Abhumans, the Ogryns and especially the Bullgryns, to defend themselves (or they’ll simply roll over you with their tanks).

What Books Do I Need to Play the Imperial Guard?

You’ll need the Codex: Astra Militarum, and there are rumors that there will be a large new range release of the Astra Militarum in the very near future which will probably include a new Codex. You’ll also, as with all of these armies, need the Core Rulebook.

What Armies of the Imperium Models Are Available to the Astra Militarum?

The bulk of the units that you’ll find available to the Imperial Guard are Cadians. This is because–according to the lore–Cadians are heroes of the Imperium due to a major battle that resulted in the fall of Cadia, and therefore other worlds mimic the uniforms of the Cadians. But I think that’s incredibly boring, because there used to be such incredible variety in the Imperial Guard.

The Codex: Astra Militarum contains 56 datasheets for all of the units, the bulk of which are armor. Arguably the most famous Imperial Guard tank is the Leman Russ (Buy on Amazon), which was the standard of quality for twenty years and resembles something out of World War One (much of the Imperial Guard seems to be taken straight from World War One, especially units like the Veteran Guardsmen (Death Korps of Krieg–Buy on Amazon), and the Hydra (Buy on Amazon).

But in the last ten years a new tank has emerged to outshine the Leman Russ, and that is the Baneblade (in its eight variants). Known as a Super Heavy Tank, it dwarfs everything else on the battlefield, and rolls in at around 400-500 points, depending on the variant.

There are two Start Collecting boxes for the Imperial Guard: first, the Start Collecting Astra Militarum, which gives you a Leman Russ Battle Tank, a Cadian Heavy Weapon Team, a Commissar, and a squad of ten Cadian Shock Troops. (Buy on Amazon) The second box is the Start Collecting Militarum Tempestus, a sort of elite Imperial Guard regiment, that gives you a squad of ten Scions, a Commissar, and a Taurox Prime. (Buy on Amazon)

Adepta Sororitas (Sisters of Battle)

What are the Adepta Sororitas

Often referred to as “Space Nuns” the Sisters of Battle are a product of an Eowyn-like loophole in the Administratum’s orders: it says that the Ecclessiarchy (the church which reveres the Emperor as a god and which therefore controls the whole of the Imperium) cannot have it’s own amry of “men at arms”… but it doesn’t say it can’t have women. So the Sisters of Battle are an ultra-religious army that is determined to Burn the Heretic at every opportunity.

Everything about the Sisters of Battle is over-the-top in terms of religious iconography as they carry relics and reliquaries, and their tanks literally are topped with pipe organs and stained glass windows.

What Books Do You Need to Play the Sisters of Battle?

You’ll need Codex: Adepta Sororitas, which contains 34 datasheets, which is quite a bit considering how “young” the Adepta Sororitas are. (The Sisters of Battle have existed for decades but only as metal models until they recieved a plastic release in 2019 and have had a steady trickle of new units released regularly since.)

What Armies of the Imperium Models Are Available for the Sisters of Battle?

Aside from the basic squad of Battle Sisters (Buy from Amazon), one of the best units in the entire game of Warhammer 40k is the Sisters Repentia (Buy from Amazon). And the tanks are great fun, whether you get the main battle tank, the Castigator (Buy from Amazon), or one of the weirder ones like the Immolator (Buy on Amazon). But perhaps their coolest-looking unit is a diorama HQ unit called the Triumph of Saint Katherine. (Buy from Amazon)
‘
There is also the Adepta Sororitas Combat Patrol, which we ranked as one of the best values of all the Start Collecting boxes, containing a Canoness, a Rhino, a Repentia Superior, a Penitent Engine, 3 Arco-flagellants, 4 Sisters Repentia, 5 Seraphim, and 10 Battle Sisters. (Buy from Amazon)

Adeptus Custodes

What Are the Adeptus Custodes?

If the Space Marines are super soldiers, and the Grey Knights are the Super Super Soldiers, then the Adeptus Custodes are the Super Super Super Soldiers. They are tasked with guarding Terra, including the Imperial Palace where the Emperor Resides on his Golden Throne.

Wearing all gold and looking not a little unlike the Stormcast Eternals–but more so–an army of Adpetus Custodes will almost always have a very low model count because the individual soldiers are so incredibly powerful and impressive.

Recently the Adpetus Custodes recieved a new release which lumped them together with the Sisters of Silence, a group that had existed previously but which had only had a handful of models. The Sisters of Silence are almost as powerful as the Adeptus Custodes, and they have the benefit of being completely immune to psychic powers. It is the Sisters of Silence who gather up all of the thousand psykers a day who are to be sacrificed to the Golden Throne.

What Books Do I Need to Play the Adeptus Custodes?

You’ll need the Codex: Adeptus Custodes, which will include everything you need for both the Custodes and the Sisters of Silence. Also, the book Psychic Awakening: War of the Spider has rules for the Talons of the Emperor.

What Armies of the Imperium Models Are Available for the Adeptus Custodes?

The Custodes have some really great models, starting with the basic Custodian Guard (Buy on Amazon) and they extremely cool jet bike models the Vertus Praetors (Buy on Amazon). For single HQ models, the Captain-General Trajann Valoris is neat (Buy on Amazon), as are the Talons of the Emperor (buy on Amazon).

When it comes to the Sisters of Silence, they haven’t really seen a range refresh, they’ve just gotten more press lately. You can get them in the Vigilator Squad, Prosecutor Squad, and Witchseeker Squad. (They can all be built from this box on Amazon.)

Adeptus Mechanicus

What Are the Adeptus Mechanicus?

The Adeptus Mechanicus are the primary, if not only, technological force for the Imperium of Man. Based on Mars and the various Forge Worlds among the Imperium, the armies of the Adeptus Mechanicus have gone above and beyond the level of cybernetics to the point where they are “more machine now than man.” And this goes beyond just the soldiers–who are very much machines–but also to the vehicles, including the Serberys Raiders, which are cybernetic horses.

The Adeptus Mechanicus also has a penchant for using radiation weapons, weapons that are never used by the bulk of the Imperium. This is because the mostly-robotic bodies of the Adeptus Mecahnicus are relatively unaffected by the radiation.

Some have called the look of the Adeptus Mechanicus to be dieselpunk, but I vastly prefer the retrofuturism of the 1940s and 1950s. It’s a small distinction, but I find it to be an apt comparison. (You can read a really long article about my thoughts on this here.)

What Books Do I Need for Playing the Adeptus Mecahnicus Army?

The Adeptus Mecahnicus have their own 9th Edition Codex with all the rules and data sheets you’ll need to play them, totalling 30 unique data sheets for a very varied and interesting amry.

The additional book Psychic War: Engine War has some additional rules which are not necessary but will come in handy if you’re playing competitively.

What Armies of the Imperium Models are Available to the Adeptus Mechanicus?

The Adeptus Mechanicus (or Ad Mech) are not an old army by any means, but it’s been a little while since they got anything new. Still, what they have looks great and up until a recent nerf, the Adeptus Mechanicus were running the table at tournaments. They still have some very strong units, including the aforementioned Serberys Raiders (Buy on Amazon), and the Skorpius Disintegrator (Buy on Amazon) makes a very good transport. Somewhat fragile, the Ad Mech can still mix it up in close combat.

Their Combat Patrol box (Buy on Amazon) isn’t bad, with a Tech-Priest Enginseer, an Onager Doomcrawler, 10 Skitarii Ranger (which can be assembled as Skitarii Vanguard) and 3 Kataphron Destroyers. I must admit that for as much as I love the look of nearly all the Ad Mech, those Kataphron simply do not do it for me.

Imperial Knights

The Imperial Knights, for being as massive and as glorious as they are, are actually one of my votes for the easiest way to get into the Warhammer 40k hobby. I know there are mixed opinions about this, but here’s my reasoning: if you’re starting you only have to paint like four models, which is pretty great, and those four models will set you back about $580 if you buy them from your FGLS or from Amazon (Buy from Amazon). They’re big, they’re insanely tough and insanely killy, and while you might not be able to table your opponent, especially if they’re playing a horde army, you can still have a raucous good game with your Imperial Knights.

The Imperial Knights are remnant from the Age of Strife when the Imperium was cut off from most of humanity’s homeworlds, and they’re full of heraldry and everything that you would expect if Brettonia was somehow transported into a massive mech army.

What Books Do You Need for the Imperial Knights?

The Knights have their own codex which is admittedly mostly filled with fluff. But make no mistake–the Imperial Knights are very killy, and very tough, and their Codex is full of all the fun weapons that they get that are just outrageously powerful. It has its share of datasheets, but most of its time is spent talking about heraldry and worldbuilding.

The additional book Psychic War: Engine War has additional rules for the Imperial Knights which aren’t essential but good for competitive play.

What Armies of the Imperium Models Are Available to the Imperial Knights?

There is clearly no starting box for the Imperial Knights, as one knight alone costs more than a collecting box by itself. If you want to start small, the Armiger Warglaive are a good introduction (Buy from Amazon) but the Knight Valiant (Amazon) and the Knight Castellan (Amazon) look too good to pass up.