"The Tech-priest tends his flock of Chimeras and lasguns as surely as his priestly brethren from the Ecclesiarchy tend the souls of their Guardsmen, and his ministrations are no less important to the continued success of the numerous campaigns of the Imperial Guard."
— Magos Aubrey Bessemer

An Enginseer of the Adeptus Mechanicus serving with the Imperial Guard

An Enginseer, also called a Tech-priest Enginseer, is a Tech-priest of the Adeptus Mechanicus whose specialisation is the maintenance and repair of the many technological instruments of the Imperium of Man, both in peace as in war. Enginseers are engineer mystics, members of the Adeptus Mechanicus who are dedicated to the Machine God and steeped in arcane knowledge. Enginseers are the most commonly seen members of the Mechanicus, for they are present wherever a somewhat technologically advanced human settlement resides. By virtue of the ancient Treaty of Mars, many Enginseers are attached to the Astra Militarum and Imperial Navy, maintaining and repairing the Imperium's vehicles, aircraft, starships, and other wargear and ensuring that the warriors who prosecute the Emperor's wars always have the means to do so. These cybernetic holy men stand aloof from the Imperial Guardsmen, concerned only with tending to the Machine Spirits of their foster regiment's many vehicles and weaponry.

Thanks to training and a lifetime of servitude to the Machine God, Enginseers can soothe even the most belligerent of Machine Spirits with binary prayer and mystic rites. Indeed, without the chanting diligence of the Enginseers, and their tireless maintenance, the Imperial Guard and Imperial Navy would soon grind to a halt.

Enginseers also appear in the armies of the Adeptus Mechanicus and, although their role still centres around their mechanical charges, they are quite capable of leading an army of the Omnissiah's disciples to war. To the soldiers of the Imperial Guard, an Enginseer is a mysterious figure, but within the Adeptus Mechanicus, he is just another cog, albeit a vital one. While other Tech-priests concern themselves with the Quest for Knowledge, Enginseers take on a more utilitarian role, tending the Servitor flocks and acting as custodians to the machines they serve.


"The machine is my temple, each one a sacred shrine. I name each piston blessed, and every gear divine."
—Hymnal of Engine Commencement

The icon used in the Astra Militarum to designate Enginseers; it is based on the Cog Mechanicum

At the very foundation of the Imperium of Man after the end of the Unification Wars in the late 30th Millennium, the Emperor of Mankind sealed a pact known as the Treaty of Mars with the Cult Mechanicus, ensuring their lasting collaboration in exchange for political and religious autonomy. As a result, the Mechanicum began to train a large number of Tech-priest Aspirants as Enginseers, to ensure that the demands of the Imperium's war machine would be met.

Enginseers are engineer-mystics, fully initiated members of the mysterious Adeptus Mechanicus and its cult. They are highly trained Tech-adepts of the Cult Mechanicus and are dedicated to the maintenance of Imperial technology. Through many standard years of study they have gained the knowledge of the rituals and litanies that form the body of Mechanicus lore, as well as a deep understanding of the more practical disciplines of mechanics and electronics. Unlike most of the Priesthood of the Mars who remain aloof from Mankind and isolated on their Forge Worlds or Explorator Fleets, Enginseers can be found serving in almost every Imperial institution, and are often assigned to the Imperial Guard or other parts of the Adeptus Terra. The only exception is the Chapters of the Adeptus Astartes, whose methods of warfare exclude any dependance on external assistance; hence they have their own "Enginseers" in the form of the Frater Astrotechnicus or Techmarines. The main difference between the two is that a Techmarine is a genetically-modified superhuman loyal to both his Chapter and the Cult Mechanicus, while the Enginseer is a mere mortal and fully human member of the Cult. However, their missions are essentially the same, and if given access to the necessary technical data, a Techmarine could carry out an Enginseer's work and vice versa.



A Tech-priest Enginseer outfitted in Power Armour armed with an Omnissian Power Axe and Mechadendrite

Conspicuous amongst the regiments of the Imperial Guard in their red Mechanicus robes, their bodies twisted by the numerous sacred augmetics that bring them closer to their Omnissiah, the tech mystics of the Priesthood of Mars maintain the Imperial Guard's and other Imperial armed forces' vast store of weapons, fighting vehicles and other various and sundry war materiel. They command armies of Mono-task Servitors, and bear with them arcane tools, and possess an abundance of knowledge concerning the workings of the sacred machine. Always, they move among their regiments' armouries, soothing Machine Spirits, and ensuring that all proper obeisance is made to the Machine God.

Many Tech-priests carry incense burners and painstakingly prepared oils with which to soothe and prepare the myriad weapons, vehicles and other machinery of the Imperial Guard and the Imperial Navy. They serve all across the galaxy with the Imperial Guard at the regimental, company and squad level, and are expected not only to tend to the machinery, but also to take up arms and, if called upon, to lay down their lives in the defence of the Imperium and its Omnissiah. Enginseers are often directly in harm's way, and rush into the thick of battle to salve the Machine Spirits of a damaged Chimera or to bring their copious understanding of engineering to bear on enemy fortifications and armour, always to the great benefit of their Imperial Guard squad-mates.

Enginseers serve as field engineers and maintenance specialists across the galaxy, often in harm's way, as those seconded to the Imperial Guard and Imperial Navy will be called upon to make repairs on the battlefield as well as in the workshop. They are a common sight on battlefields with large numbers of armoured vehicles, and are often accompanied by a retinue of Servitors for assistance and protection. Although most Guardsmen revere their vehicles enough not to risk annoying an Enginseer by "tinkering" or outright adapting it, the modification of vehicles to fulfill a certain need is inevitable, much to the chagrin of any Enginseers present, for their work to ministrate and placate the vehicle's Machine Spirit will be made more arduous by the non-standard deviations.

Enginseer contingents also accompany the Mechanicus' mighty Titan Legions and the crews of the massive warships of the Imperial Navy, carefully monitoring these mighty machine's systems and entreating their ancient Machine Spirits to function efficiently with rituals of placation and maintenance. In the heat of battle, the Enginseers will ease the machine's pain, performing damage control and field repair procedures, keeping their charge functional and willing to fight.

Despite the respect they usually command among the units they are seconded to, Enginseers are not held in high regard among the Cult Mechanicus itself as their skills seldom contribute to the the Quest for Knowledge. As a result of their overwhelmingly practical knowledge, they are often viewed as lowly but necessary cogs in the workings of the Machine God's order.



An Enginseer of the Adeptus Mechanicus armed with an Omnissian Power Axe

On the battlefield, Enginseers prove extremely useful, for they can effect battlefield repairs and rouse machine spirits to wrath. Enginseers are clad in sanctified Power Armour specially modified to match their needs, allowing them to wade fearlessly into the fray. Enginseers seconded to the Imperial Guard often outfit themselves with cybernetic enhancements and protections to augment their survivability. The Enginseers also carry a Laspistol and a Omnissian Power Axe, the typical long-shafted, two-handed halberd-like contraption which is as much a weapon as a tool as a religious icon to the members of the Adeptus Mechanicus. The Enginseers often make use of multiple robotic arm augmentations known as Mechadendrites that are connected to their central nervous system via the spine, and are used to assist them in repair operations. Alternatively, the Enginseer can opt to equip himself with a Servo-arm, which is more practical for heavy lifting and for self-defence.

Many Enginseers are also accompanied by a group of Servitors, who are either equipped with additional heavy tools to assist in repairs, or heavy weaponry if the Enginseer estimates that the safety of his ministrations cannot be guaranteed by the surrounding Imperial Guardsmen. 

Astra Militarum Hierarchy
General Officers Lord Commander MilitantWarmaster (Lord Solar) • Lord CommanderLord General MilitantLord GeneralGeneral
Officers ColonelMajorCaptainLieutenant
Non-Commissioned Officers and Enlisted SergeantCorporalTrooper (Guardsman)
Specialists InquisitorCommissarPriestTech-PriestEnginseerSanctioned PsykerPrimaris PsykerWyrdvane Psyker


  • Codex: Adeptus Mechanicus (8th Edition), pp. 41, 75
  • Codex: Astra Militarum (8th Edition), pp. 61, 100
  • Codex: Imperial Guard (5th Edition), pg. 38
  • Codex: Imperial Guard (3rd Edition, 2nd Codex)
  • Dark Heresy: The Lathe Worlds (RPG), pg. 11
  • Fanatic Magazine 5
  • Total War: Core Rulebook Beta (RPG), pg. 62
  • Warhammer 40,000: Chapter Approved - The Book of the Astronomican
  • Warhammer 40,000: Core Rulebook (8th Edition), pg. 71
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