Warhammer 40k: Adeptus Mechanicus guide 2023

Warhammer 40k's Adeptus Mechanicus army is a complex beast in 9th edition - here's what you need to know to marshal the machine cult of Mars.

Warhammer 40k Adeptus Mechanicus 9th edition guide warhammer community photo showing the new Skitarii Marshal model

The Warhammer 40k Adeptus Mechanicus faction might be the most inhuman, contradictory offshoot of the human species in the Dark Millennium of Warhammer 40k. It is a religious cult devoted to technology, both superstitious of science and yet utterly avaricious in the pursuit of knowledge.

If you want an imposing, flexible, and customisable army that packs serious firepower, look no further than the Adeptus Mechanicus. If you’d prefer something simpler, check out our list of the other Warhammer 40k factions – with Warhammer 40k 10th edition all the rules are free, so you can check out every faction without spending a nickel.

Our guide should give you a firm grounding in the Adeptus Mechanicus’ techno-mystical lore, and their mighty strength at (robot) arms.

Adeptus Mechanicus in Warhammer 40k 10th edition

The Warhammer 40k 10th edition Adeptus Mechanicus are substantially simplified compared to ninth edition edition – no bad things, as the Adeptus Mechanicus had one of the most bewilderingly complex Warhammer 40k Codex army books in ninth edition.

Click here to download your free Adeptus Mechanicus Warhammer 40k 10th edition Index rules.

Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Doctrina Imperatives

Adeptus Mechanicus 10th edition army rules

The main Adeptus Mechanicus 10th edition army rules are the Doctrina Imperatives. At the start of the Battle Round you’ll get to pick a Doctrine: the Protector Imperative grants units the Heavy Weapon Ability and an armour buff in your deployment zone; while the Conqueror Imperative grants the Assault Weapon Ability, plus additional AP when targeting units in the opponent’s deployment zone.

Doctrina Imperatives existed in ninth edition, but only applied to Skitarii units, and came with a penalty as well as a buff. The new ability helps everyone equallyWarhammer 40k 10th edition Adeptus Mechanicus rules preview - Rad-cohort detachment Rad-Bombardment rules

Adeptus Mechanicus 10th edition Detachments

The first Adeptus Mechanicus Detachment for 10th edition is the Rad-cohort. It has a wonderfully grimdark narrative: at the start of the battle, you bombard your opponent’s deployment zone with radiation.

Your opponent’s units can either risk suffering mortal wounds, or become Battle-Shocked for the turn. From the second turn onwards, enemy units that remain in their deployment zone risk suffering additional mortal wounds.

Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing a painted Tech Priest Dominus model

Sadly, this is a pretty weak ability. Missions aren’t scored in the first round of the game, so the only penalty from Battle-shock is the inability to use Stratagems – if it’s really important that a particular unit uses a Stratagem, your opponent will accept the mortal wounds on that unit. This is very poor against the Dark Angelsclass="gallery">, whose Unforgiven Task Force actually gets more powerful when some units are Battle-shocked.Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Aggressor Imperative stratagem

There are six unique Warhammer 40k Stratagems for the Rad-Cohort. Some of them only be used while a specific Doctrine is active for your army. For 1CP the Aggressor Imperative allows a Skitarii unit to charge after advancing, provided the army is using the Conqueror Imperative, while the Bulwark Imperative gives a Skitarii unit a 4+ invulnerable save against shooting, provided the army is using the Protector Imperative.

Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Bulwark imperative stratagem

Adeptus Mechanicus 10th edition synergy

Part of the Adeptus Mechanicus’ complexity has always come from the many buffs and synergies between its units. While this has traditionally been the result of tech-priests tinkering with their servants’ programming, in 10th edition battleline units, such as the Skitarii Rangers and Skitarii Vanguard, activate additional abilities for their fellow servants of the machine god.

Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Sicarian Ruststalkers optimised gait rules

For example the Sicaran Ruststalkers get +1 to Advance and Charge rolls, which increases to a +2 bonus when they’re within 6” of a Battleline unit.

Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Skitarii vanguard datasheet

The Skitarii Vanguard Datasheet and their Rad-saturation aura is a potent tool for controlling objectives: while within 3” of the Vanguard, non-vehicle enemy units suffer -1 to their objective control value. Space Marine terminators can’t contest objectives with radiation poisoning.

An Adeptus Mechanicus army is a holy crusade of fanatically devout warriors, wielding arcane superweapons that rain the wrath of their beloved Omnissiah onto their enemies. On the tabletop, this is represented by – arguably – the coolest model line in all 40k: quad-limbed Onager Dunecrawlers sporting huge Neutron Lasers march to war, thronged on all sides by masses of irradiated Skitarii Vanguard infantry.

Talons of Pteraxii Sterylizors descend on bionic wings to scorch their foes with cleansing flame. Cybernetica Datasmiths inload their Kastelan Robot charges with new war codes, while Kataphron Destroyer servitors rumble forwards on heavy tracks to bring immense weapons to bear on the foe.

Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing skitarii vanguard models with various weapons

Adeptus Mechanicus lore

What can the Adeptus Mechanicus lore tell us about these confounding, chrome-limbed enigmas? Though the AdMech prize logic and calculation, and deride emotion, they are driven by a fanatical devotion to the cult of the Machine God.

They are the custodians of mankind’s technology and knowledge, yet these invaluable secrets are cloaked in ritual and mystery. They abhor the alien for its deviance from the holy human form, but spend their unnaturally extended lives purging their bodies of weak flesh and replacing it with cold metal.

The Adeptus Mechanicus predates the Imperium of Man. Though holy Mars was terraformed in ages long past, the planet was consumed by industry, choked beneath the radiation and waste of a million forges, and the aftermath of ancient wars.

Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing a mixture of Skitarii infantry models

During the long Age of Strife, when the first human galactic civilisation was torn apart by Warp storms and preyed upon by alien and daemonic horrors, on the red planet, technology meant life. Soon a cult of machine worship took hold. Mars was the first Forge World, and its fabricator-kings became the Mechanicum.

Throughout that long night, Mars sent out explorator fleets in a blind attempt to regain contact with lost human colonies and build new dominions. A precious few of these would survive, seeding new Forge Worlds in the image of Mars – each of which would go on to develop their own cultures and variants on the Martian Creed.
Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing kastelan robots and a cybernetica datasmith

When the Emperor first conquered Terra and initiated the Great Crusade, Mars was brought into the Imperium as a vassal state. In exchange for providing the ships, arms, and armour needed by the great warhosts of the Imperial Army and Legiones Astartes, Mars was offered control of the human technology it recovered.

This alliance was shattered during the Horus Heresy, as half of the Mechanicum was lured to the cause of the traitors by Chaos’ promises of forbidden, arcane technology. During this great cataclysm, treasure troves of knowledge and artifice were lost, annihilated in the fires of treachery, and even Mars itself became a boiling cauldron of internecine strife.

Warhammer 40k Adeptus Mechanicus 9th edition guide warhammer community artwork showing a tech priest and various servitors

During the Heresy, the loyal elements of the Mechanicum reformed into the Adeptus Mechanicus. Though they are bonded closely to the Imperium of Man, and their highest official, the Fabricator General of Mars, holds a permanent position as one of the twelve High Lords of the Imperium, they are still a culture apart.

Their devotion to the Emperor is in his aspect as the Omnissiah, corporeal embodiment of the Machine God. Their commitment to the wars of man is for the preservation and recovery of ancient technology, not the defence of human lives.

Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing a painted tech priest enginseer model

Indeed, the Adeptus Mechanicus have a callous disregard for human life, but a holy reverence for the machine. For them, all technology is an expression of the will and eminence of the Machine God, and the operation of everything, from physics to biology, is an expression of His divine Motive Force.

They see themselves as advancing a great work, bringing about a perfect mechanical creation. It does not matter to them how many billions of humans die in service to that vision.

Warhammer 40k Adeptus Mechanicus 9th edition guide photo showing the model for Belisarius Cawl

Adeptus Mechanicus characters – Belisarius Cawl

There’s only one Adeptus Mechanicus special character model, but he casts a long shadow – and not just because his body is a cybernetic centipede over 10 feet tall.

No Tech-Priest, save perhaps the Fabricator General of Mars, has put their maker’s mark on Warhammer 40k’s current narrative cycle – the Era Indomitus – as firmly as Belisarius Cawl.

Long ago, in the wake of the Horus Heresy, the Imperial Regent Roboute Guilliman tasked Cawl with a project of dread importance. For the next ten millennia, Cawl worked in secret, using genetic lore from the Emperor’s Primarch project and his own techno-archaeological discoveries, in order to found the mighty warhost of the Primaris Space Marines.

Only with the resurrection of Guilliman, and the coming of the Great Rift, has Cawl finally unleashed these upgraded warriors in aid of the Imperium. In short: all the shiny new Space Marine vehicles and weaponry that have been released since eighth edition dropped in 2017 are the product of Belisarius Cawl’s mad genius.

Cawl has changed a lot in the 10,000 or more years of his life, literally losing his mind (or at least some of his ancillary data-stacks) several times, but he’s always been arrogant – and borderline heretical – in his willingness to experiment with holy technology.

You can learn more about him as a young man in Wolfsbane, Horus Heresy book 49, or his exploits in the Era Indomitus in The Great Work. You’ve got to admire his confidence: The Great Work involves a heist on a Necron tomb complex, right under the noses of a Genestealer infestation. He’s certainly got big ball bearings.

Warhammer 40k 10th edition Adeptus Mechanicus rules preview - Belisarius Cawl datasheet

Fielding Belisarius Cawl

Belisarius Cawl is an Epic Hero, and he’s fittingly a beast on the tabletop. Armed to the teeth with the finest guns and weapons available to the forges of Mars, such as the Solar Atomiser (12”, Assault d3 Blast, S10, AP -4, Damage D3 or D3+3 against targets within 6”), he also packs a suite of command abilities.

Each round, Canticles of the Omnissiah allows him to pick one of three aura abilities, granting Adeptus Mechanicus units within 6″ rerolls on to-hit rolls of one, re-rolls on Battle-shock or Leadership tests, or the Stealth ability.

With thanks to Mel Bushell for her fantastic dark-robed Dominus, Nerodine for his gorgeous Vanguard unit, Heather’s fetching dark jet tech-priest, JB for his impressive quartered red and yellow robots, and Pandaemonium Miniatures Paul’s sinister purple Skitarii.