Warhammer 40k Astra Militarum codex and lore guide 2025

The Warhammer 40k Astra Militarum army – a.k.a. the Imperial Guard – is among the oldest and most popular playable factions in Games Workshop’s sci-fi wargame. An enormous force of trillions of regular humans, the Guard are humanity’s first defence. This complete guide now includes full details of the new 2025 Astra Militarum codex, as well as the brand new Death Korps of Krieg models – so read on for everything you need to collect and play Imperial Guard in 10th Edition!

For an explanation of all the other armies fighting it out in GW’s grimdark galaxy, read our full guide to the Warhammer 40k factions. And to find out which armies are getting new rules next, check our updated list of Warhammer 40k codex release dates.

Use the links below to jump to what you need – from the lore and background of the Astra Militarum and the various Imperial Guard regiments, to our breakdown of the 10th edition codex, and more. I’ve even added glamor shots of my own Astra Militarum regiment – the 728th Nassau Hoplites – to show that even averagely painted Guard models can look badass!

Who are the Astra Militarum?

In Warhammer 40k, the Astra Militarum (affectionately called simply ‘The Guard’) is the primary standing army of the Imperium of Man. It’s composed of billions (possibly trillions) of unaugmented, ordinary human soldiers, drawn from planets all over the galaxy, and organised into millions of vast regiments.

Those countless human infantry soldiers are backed up by enormous numbers of Warhammer 40k tanks, support vehicles, and aircraft maintained by the Adeptus Mechanicus; supported by battlefield specialists including sanctioned psykers; and ferried to wars across the galaxy in the void-ships of the Imperial Navy.

The ‘Guard’ has existed, in various different structures and under different names, for over 10,000 years, since its original formation by the Emperor of Mankind in the late 30th Millennium to help fight his Great Crusade.

At that time it was called the Imperial Army (Imperialis Auxilia) – and would play a massive role in the many battles of the Horus Heresy civil war, with army regiments fighting alongside Space Marine legions on both the traitor and loyalist sides.

Of all the 40k armies to collect, play, and read Warhammer 40k books about, the Astra Militarum may be the most dearly beloved by fans. There are lots of reasons for that, but we reckon relatability is top of the list – these troopers are just regular old humans like you or I, and that means we can feel their pain, their fears, and their triumphs more keenly.

In the far future of the 41st millennium, the Emperor’s domain is beset by dangers beyond comprehension, from nefarious Chaos Space Marines wreaking revenge on the empire that exiled them, to the encroaching alien menace of the Tyranid hive fleets – insectoid swarms bent on consuming the whole galaxy.

The Guard face all those terrifying foes with nothing but flimsy armor, low-power laser guns, old fashioned bayonets, and slow, clunky tanks slammed together on a budget – and they often win. That’s a compelling theme for sci-fi wargamers.

Sure, the most famous defenders of humanity are the Space Marines, gene-crafted demigods who stand as a bulwark against the worst the universe has to throw at them. They’re peerless in battle, but they’re few, and can’t win galactic wars on their own.

In their own way, the human soldiers of the Imperial Guard boast far more bravery, grit, and determination than even the Adeptus Astartes can muster.

Astra Militarum codex and rules for 10th edition

Games Workshop is releasing the 10th edition Astra Militarum codex rulebook as part of the Death Korps of Krieg army set on January 25. The regular, standalone edition will come out separately, most likely a couple of weeks later.

If you’re new to 40k, this is the dedicated rulebook for the Astra Militarum army, which you’ll need to play. Alongside some lore details, it contains your core army rule, all the datasheets which explain how your units, weapons, and abilities function in-game, and five distinct Warhammer 40k detachments you can build your army around.

Luckily, GW sent me an advance copy for review – so I’ll break down all the new rules for you below in plain English!

Army rule – Voice of Command

Identical to the one found in the existing Index rules, the Astra Militarum’s core rule, Voice of Command, is all about using your army officers to yell Orders at the troops, giving the right bonuses to the right units, at the right times.

In the command phase at the beginning of each turn, each of your officers can issue one (or more) orders to a unit within six inches of them, and the target unit will get a specific benefit until the next command phase.

There are six orders available – here’s what they do:

1. Move! Move! Move! – Add 3 inches to target unit’s move.
2. Fix Bayonets! – Add 1 to target unit’s Weapon Skill.
3. Take Aim! – Add 1 to target unit’s Ballistic Skill.
4. First Rank, Fire! Second Rank, Fire! – Add 1 to Attacks for target unit’s Rapid Fire weapons.
5. Take Cover! – Improve target unit’s save by one (max 3+).
6. Duty and Honor! – Improve target unit’s Leadership and Objective Control stats by 1.

Lower ranking officers can only issue one order per turn, but more powerful characters can hand out two or even three. Remember, though, that a unit can only be affected by one order at a time (unless some other ability lets them benefit from more).

Detachments

The 10th edition Imperial Guard codex has five detachments that – somewhat unusually for an army that’s often been seen as pretty one-track – genuinely offer distinctive ways to play and win games.

Each detachment has its own unique Detachment Rule which, together with the Army Rule, will define your core strategy by making you stronger in one particular area. Within each detachment, you also have a menu of four paid Enhancements to buff up your characters, and six custom Stratagems to activate for bonuses at crucial moments  during the game (at the cost of Command Points).

Here are the five detachments, with a breakdown of their key rule, and a summary of their best bits.

Combined Arms

Siege Regiment

Mechanized Assault

Hammer of the Emperor

Recon Element

As with all the new Warhammer 40k 10th edition detachments, each of these gameplay-distinctive ways to play the army is ‘subfaction agnostic’ – so it can be applied to any army list, regardless of which lore-appropriate (or home-brewed) regiment you want your Astra Militarum force to come from.

This is a departure from previous editions, where different rule sets within each faction were directly tied to officially mandated sub-factions like the Cadians, Catachans, or Armageddon Steel Legion. Some regiments from the lore do have specific units that lean more towards one detachment’s strategy than others.

For example, the newly reinforced Death Korps of Krieg’s Artillery Team has access to more powerful gunnery than the Cadians’ Field Ordnance Battery, so might make for better fire support in a Siege Regiment army; that detachment is directly themed around GW’s background fiction for the Krieg armies.

But it’s all just down to personal preferences of theme and models. There are no formal restrictions on mixing Death Korps of Krieg, Cadian, and other models in your army, regardless of detachment choices – I’m thoroughly looking forward to welcoming Krieger reinforcements into my majority-Cadian force. 

Astra Militarum Combat Patrol

One of the prime benefits of an Astra Militarum force is the breadth of troops, models, and Imperial Guard tanks available to you. Whilst it’s incredibly exciting to look at the variety you can choose from, it can also be a little overwhelming. Luckily, there’s a definitive place to start: the Astra Militarum Combat Patrol box.

This Combat Patrol starts you out with a Cadian Command Squad, plus a two full squads of Cadian Shock Troops to back them up. The box also features an Armoured Sentinel, Ordnance Teams, and a Cadian Infantry Transfer Sheet. You can expect a smidgen of personalization options to make the army feel more your own, but this is just the first stepping stone to exploring all Astra Militarum has to offer.

Astra Militarum regiments

Throughout the Imperium, thousands of planets are compelled to form their own Imperial Guard regiments, conscripting many millions of troops in the name of the God Emperor. The Imperium is colossal beyond all imagination – so you can create your own Imperial Guard regiment, customising them to use the rules and paint schemes you prefer.

However, the setting features several ‘official’ Imperial Guard regiments that have become legends throughout the Imperium, and, as a result, have often had specific rules and histories in the game. Here are some of the most popular and famous regiments known to humanity – we’ll start with the ruthless, gas-masked men and women of the hour…

Death Korps of Krieg

Of the many regiments, the intimidating Death Korps of Krieg are the one you’ll see most of right now, as Games Workshop has just released a whole army set for them, with more brand new kits to come. But just who are these grim-looking, trench-coated guys? In short, they’re the most fatalistic, dogmatically loyal, and fearless warriors in the whole damn Guard – and that’s because of their horrific, tragic backstory.

The planet of Krieg once suffered a civil war, with many trying to secede from the Imperium. After centuries of brutal trench warfare and atomic bombardment, the loyalists raised the Imperial aquila above a ruined world.

Today, in shame, the Death Korps of Krieg attempt to make up for this betrayal by fighting harder, suffering more, and pushing themselves past fear in service of the Imperium. Though the Krieg would never reject their duty, no matter how onerous, they have an unfounded reputation for seeking death. They know that their life belongs to the Emperor, and it is his to take when he wills it, not theirs to throw away.

Armageddon Steel Legion

The hive world of Armageddon is known for fending off a colossal horde of Orks on several separate occasions. As a result of the many invasions it’s survived, the planet maintains a large Imperial Guard regiment, known as the Armageddon Steel Legion. On the tabletop, an Armageddon force naturally gravitates towards keeping your troops safe in transports, popping out to deal damage. For example, their order Mount Up! lets a target unit immediately hop on a nearby transport after shooting, keeping them safe for another turn.

Cadian Shock Troopers

For millennia, the planet Cadia held vigil over the Eye of Terror, a hideous rent in space-time where reality overlapped with the raw stuff of Chaos. This proximity to humanity’s most deadly enemies led the Cadian forces to become one of the most famous and most numerous of all.

Alas, during Abaddon the Despoiler’s 13th Black Crusade, Cadia was finally destroyed. The Cadians may have lost their home, but they have not lost their determination. As their last commander, Ursarkar E. Creed said, “The planet broke before the guard did”. With untold millions of Cadians serving in wars across the galaxy, they fight on, taking the fight to Chaos wherever they can.

Catachan Jungle Fighters

This death world is a jungle paradise, until you set foot on it. Everything wants to kill you there, and we do mean absolutely everything. The Catachan Jungle Fighters make up the core of this Imperial Guard regiment, deadly foes who look down on anyone who hasn’t suffered as they have.

The Catachan’s have a reputation for strength and brutality, and have earnt the nickname “little Ogryns” – but don’t let them hear you say that. They don’t take to Imperial discipline too kindly, and there is a particularly high rate of mysterious accidents among Commissars assigned to Catachan regiments.

Mordian Iron Guard

The Mordian Iron Guard Regiment hails from the tidally locked hive world of Mordian. One half of the planet is a scorching desert pointed constantly towards the system star, while all human settlement exists in hives on the frigid dark side. A sinister world, its regiments have a reputation for ruthless discipline and efficiency.

Mordian has resisted repeated Chaos incursions, and has a proud history of dispatching regiments to fight in the Emperor’s wars throughout the galaxy. The planet itself is located in Segmentum Obscurus on the far side of the Great Rift, meaning it is isolated in Imperium Nihilus. While all Mordian soldiers expect to die in duty, they now face the disquieting uncertainty that their home world is inaccessible and, possibly, lost.

Tallarn Desert Raiders

During the dark time of the Horus Heresy the world Tallarn was ravaged by an unforeseen invasion of the Iron Warriors. They rendered the planet toxic to all life with a virus bombardment, before commencing a ground assault in armored vehicles in search of some inscrutable prize.

The tank war that followed was the largest in the history of the Imperium, and its aftermath shaped the face of Tallarn for millennia since. Talarn is a lifeless desert world beset by dust storms whose population live in underground bunkers. The Tallarn Desert Raiders are experts in both light infantry combat and armored warfare, often using nimble infantry forces to harass, ambush, reconnoitre, and undermine the enemy before committing a decisive armored assault to finish the foe.

Valhallan Ice Warriors

Valhalla was a verdant world when it was first settled by humankind, and quickly became a bastion of civilization, but a collision with an iron meteorite drove it out of its orbit, rendering it into a frigid land of ice and death. If this environmental catastrophe were not enough, it was followed immediately by an invasion from an Ork warfleet.

The people of Valhalla proved their resilience against two terrible foes, starvation and the greenskin horde. The Valhallan Ice Warriors are winter warriors without compare, adept at surviving privation like few other regiments.

Vostroyan Firstborn

An industrial world, Vostroya has close links to the Mechanicus and Mars in particular. Their weapons tend to be well-maintained, out-performing other Imperial Guard regiments under similar circumstances. Their guard regiment, the Vostroyan Firstborn, may seem proud and ostentatious, but it is also a cover for a deep cultural shame.

During the Horus Heresy Vostroya was a hub of materiel manufacture for the Imperium. When the call to to defend the throne world against Warmaster Horus was issued, Vostroya refused to raise regiments, claiming that its manpower would be better served producing weapons for the war effort. Ever since it has pledged the firstborn children of its noble households to His service, to make amends for their laxity in the Imperium’s direst hour.

How to convert Astra Militarum models

Out of all the armies in Warhammer 40k, the Imperial Guard are maybe the best positioned for conversions; hell, even an Airfix kit can be easily taken apart and utilised in an upgrade or visual change for your army.

The Astra Militarum allows for a huge degree of customization, with many stunning armies being made up of innovative and creative Imperial Guard conversions. As the entire design behind the Astra Militarum takes inspiration from World War II and World War I armies, you can easily mix in third-party parts or models from ranges like Warlord Games’ Bolt Action, or even Black Powder, to spice up your army’s visual appeal.

At the very easiest level, you can very easily personalize tanks by modifying infantry models to ride along on their hulls – or cut the legs off officers and stick them in the cupola to become Tank Commanders, as I’ve done with a Militarum Tempestus Tempestor Prime and a Leman Russ in the photo below.

Many companies, such as Pig Iron Productions, Victoria Miniatures (whose Guard-flavoured ‘Scrapper’s Bag of Bits’ product image you see above, or Anvil Industry also make troops that either focus on accurate historical miniatures, or ones that combine history with science fiction, making their models and conversion bits ideal for your Imperial Guard Conversions. If you want to diversify your forces, some companies offer a wider range of female model options, such as the excellent Bad Squiddo Games.

And that’s all you need to know about the Emperor’s loyal Astra Militarum for now! For more deep dives into the best bits of Games Workshop’s far future, try our guide to the very best Warhammer 40k games on PC and console. Alternatively, follow Wargamer on Google News to keep up with our daily updates on all things grimdark.

Source: Wargamer