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"Everything organic we know of is simply machinery, in one form or another. Tendons replace pistons; flesh in the place of steel; blood is simply biological coolant. To deny this and shun it is more than just Mechanicus orthodoxy -- it is idiocy."

—Attributed to an unknown genetor

A genetor or Magos Biologis of the Adeptus Mechanicus

A genetor, sometimes referred to as a magos biologis, is a high-ranking Adeptus Mechanicus Tech-priest usually bearing the title of magos who is essentially a geneticist, zoologist, xenobiologist, xenographer and molecular biologist all rolled into one, studying all matters genetic, anatomic and biological.

A genetor numbers alongside the logis, artisan and magi ranks of the Adeptus Mechanicus as members of its ruling Priesthood of Mars, possessing access to knowledge and resources far beyond that of the lesser enginseers and lexmechanics. Yet a genetor's professional obsession with organic life often makes them seem strange to their more mechanically-inclined brethren, who comprise the majority of the Mechanicus.

For the most part, genetors differ little from other Tech-priests -- they bear the same manner of augmetic implants, venerate information and understanding as the manifestation of divinity in the universe, and engage upon the Quest for Knowledge in much the same way.

The difference is that they are not so quick to judge flesh and blood as inferior to steel and plasma and view living creatures simply as extremely complex and adaptable biomechanical machines. Where some are content to make this observation distantly, others embrace it, seeking to improve their forms not with steel, but with better engineered flesh and blood.

To an unknowing observer, a genetor may appear little different to any other Tech-priest when swathed in their crimson robes. However, where most Tech-priests' mass is derived from steel reinforcement and implanted armour plate, a genetor may have augmented themselves with vat-grown muscle, toughened, carapace-like skin, and organically-reinforced bones.

Founding of Space Marine Chapters[]

A primary duty of the Adeptus Mechanicus' genetors is receiving and studying the gene-seed tithes of all Chapters of the Adeptus Astartes for genetic corruption or deficiencies which has been required since the Second Founding.

The Horus Heresy had revealed weaknesses in the gene-seed of several Space Marine Legions. These defects had been exacerbated by the accelerated gene-seed cultivation techniques needed to keep the huge formations of the Space Marine Legions up to strength in the terrible conflicts being fought at the time of the Great Crusade. The insidious powers of Chaos had been able to manipulate this genetic corruption to turn the Warmaster Horus and many of the Space Marines under his command against the Emperor. Once Horus was defeated following the Siege of Terra, it was decided by the new Lord Commander of the Imperium and Imperial Regent Roboute Guilliman during the Time of Rebirth that the military forces of the Imperium would be reorganised so that a similar catastrophe could not be repeated.

The Space Marine Legions were divided up to create one Chapter of the same name as its original First Founding Legion and many other Chapters with new names. This event was called the "Second Founding," and over two dozen further Foundings have occurred in the ten standard millennia since.

During the Second Founding, it was determined that the first objective of the magi biologis was to recognise and expunge these genetic weaknesses in Astartes gene-seed. Space Marines would be created and trained far more slowly than during the height of the Great Crusade. The stored gene-seed used to cultivate the Astartes implants that turn a normal adolescent male into a transhuman Space Marine would be carefully monitored, and cultivated organs would be subject to the most stringent tests of genetic purity.

Young initiates would undergo rigorous trials of physical and psychological suitability before they were accepted into the Adeptus Astartes, and only those of the highest calibre would be chosen. On Terra, the Adeptus Terra created genetic repositories to produce and store Space Marine gene-seed. These storage facilities were used to provide new gene-seed for newly founded Space Marine Chapters.

To prevent cross-contamination, the genetic material of each of the old First Founding Legions was isolated. Henceforth, the new Space Marine Chapters would receive gene-seed only from their own genetic stock. The remaining stocks of gene-seed taken from the Traitor Legions before their fall to Chaos was placed under a time-locked stasis seal, although many believed these dangerous stocks of genetic material should be destroyed outright.

By taking direct control of the genetic stocks, the mortal adepts of Terra could ultimately control the Space Marines in the wake of the betrayals of the Horus Heresy, for they alone now had the power to destroy or create Chapters of the Adeptus Astartes at will.

Becoming a Genetor[]

The difference between a genetor and a more conventional Tech-priest is one of training, aptitude and focus. As is so frequently the case in the Adeptus Mechanicus, understanding begets power, which in turn begets knowledge, and only those who possess the will and the wit to understand that knowledge can properly obtain any form of status amongst their kind.

A particular and unusual disposition among the Tech-priests is required to become a genetor; the tendency to view organic life as a form of machine in its own right, rather than as the weak, fleshy shell many Tech-priests seek to cast off for the purity of steel and plastic.

Beyond this, however, it takes primarily dedication and research for a Tech-priest to become a genetor, using their knowledge of organic life to aid the Imperium in the realm of the biological sciences.


"Subject species "Ork," height is 218.6 cm, 25.56 cm above observed mean. Mass is 163.15 kg, consisting mostly of dense skeletal structure and musculature, and 31.4% above observed mean. Epidermal layer is thick and lacking in nerve endings compared to the Human norm. Pain response is...less than anticipated, demonstrating extreme tolerance for discomfort. Previous test has awakened subject, and it now attempts to free itself. Muscle relaxant administered to reduce disruptive motion, at 460% of Human standard dosage -- tolerance for chemical influences is considerable. Preparing to open chest cavity..."

—Genetor Aurelius Thoze, Adeptus Mechanicus Xenobiologist, working notes

The genetors' interest in the organic not only pertains to the Human form, but to the study of xenos life as well. The study of alien genetics, intended to better understand their physiological and psychological processes and thus how to better slay them, falls to a sub-sect of genetors collectively known as the "xenobiologists."

The study of alien genetics is a common field of study for genetors. Such knowledge is dangerous in the theocracy that is the Imperium of Man, and many genetors have been condemned as Heretics for claiming the superiority of a particular xenos species' biology to that of Humans in contravention of the doctrine of the Imperial Creed.

Regardless, the presence of a genetor, particularly a xenobiologist, is seen as an asset by Adeptus Mechanicus Explorator fleets and Rogue Traders alike, as their knowledge of Human and inhuman forms allows them to discern the nature of a newly-encountered xenos or indigenous species, or categorise a new strain of Abhuman found on a far-flung world.

Genetors are also known to introduce common Imperial animals to a new colonial ecosystem, such as the Grox, a large reptilian animal that serves as a common food source on many Imperial worlds.

Calixian Genetor Philosophies[]

Within the Calixis Sector, Genetors have a particularly illustrious history -- xenobiologists in great numbers joined the Angevin Crusade to study the aliens native to the region as their realms were shattered by the forces of the Imperium.

Since that time, they have remained a noteworthy, if often overlooked, element of Cult Mechanicus politics within the Calixian Forge Worlds of the Lathes and beyond, and they gather in significant numbers to join expeditions into the frontier space of the neighbouring Koronus Expanse, seeking to be the first to dissect and analyse new life.

Over time, three distinct philosophies have emerged amongst the Calixis Sector's genetors, which are similar to factions found among almost all genetors at large:

  • Primus Humanum - The first and oldest of the three philosophies espouses the divine purity of the Human form and physiology as a vessel for knowledge, viewing the Emperor's form as that of the ideal intelligent being in the universe.
  • Apexists - The second and presently most dominant philosophy amongst the genetors of the Lathe Worlds are the Apexists, who believe that adversity breeds strength in the organic, and that the perfect organism is the one that has overcome every rival and every challenge. The philosophy itself is an adaptation of the writings of an ancient pre-Imperial biological scholar named Charles Darwin.
  • Vogelists - The third philosophy, currently gaining favour amongst more widely travelled genetors and causing concern amongst more traditional genetors, is espoused by the Companions of Vogel, whose leader, Heydrich Vogel, returned from a standard-century-long expedition into the Koronus Expanse and began preaching a creed of forced genetic and biological augmentation in order to strengthen Humanity for the troubles ahead. Some believe that Vogel's ideology verges upon heresy, and its suggestion that baseline Humanity is somehow insufficient in its current state is seen by many among the Adeptus Mechanicus and the Ecclesiarchy as being blasphemy in its own right.

Genetor Factions[]

  • Organicists - A faction of the Adeptus Mechanicus, the Organicists are a group of Tech-priests who esteemed biological enhancement as being equal in value with the cybernetic, a somewhat radical if not heretical position from most Tech-adepts' point of view.

Notable Genetors[]

  • Magos Biologis Xebal Astolax - Prior to the Gothic War, patrol vessels found Imperial voidships drifting uncontrolled through Wilderness Space in the Athena Sector of the Segmentum Obscurus (ca. 140.M41), and boarding parties found the crews had been killed by disease. Magos Biologis Xebal Astolax examined corpses from the merchant vessel Shanxi. He listed symptoms of the disease that had killed the crew, which included fungal growths within the brain cavity, which would have caused extreme pain and delirium before the crew died. Inquisitor Horst attempted to link an attack on the Arx monitoring station to this assault. He learned of rumours of assaults on Imperial shipping by the Murder-class Cruiser Plagueclaw, crewed by followers of Nurgle, that were spreading among Imperial Navy commanders.
  • Magos Genetor Nexin Orlandriaz - Nexin Orlandriaz was a notable Magos Biologis during the Great Crusade and Horus Heresy. After the disaster of the Drop Site Massacre at Isstvan V, he became instrumental in assisting the Raven Guard Legion with rebuilding their sorely depleted numbers. Consumed by the loss of over 75,000 of the XIX Legion's Astartes, and obsessed with thoughts of revenge against Horus, the Primarch Corvus Corax ordered his survivors to return to Terra, where he intended to ask the Emperor Himself for help in rebuilding the Legion. Following a number of delays and setbacks, and despite the disagreement and displeasure of Rogal Dorn and Malcador the Sigillite, Corax psychically communed with the Emperor, who revealed to him that the original Primarch Project's genetic assets had not been destroyed, but still existed and were dormant -- and these assets included living samples of the original gene-stock the Emperor had later used to create and differentiate the 20 primarchs. The Emperor, who offered no explanation as to why such facilities and the primarch gene-stock still existed, demanded only one thing: this genetic material could never be allowed to fall into the wrong hands. Accompanied by several Raven Guard squads, a contingent of Mechanicum specialists, including Magos Genetor Orlandriaz, and a number of Custodians to serve as the Emperor's "overseers," Corax managed to locate and enter the Emperor's well-protected gene-laboratories deep beneath the Imperial Palace in the Himalazian (Himalayan) Mountains, after his strike force suffered a number of casualties. The original, undifferentiated primarch gene-stock and related technical information was secured, and Corax and his Raven Guard warriors returned to their homeworld of Deliverance to begin remaking the Legion. After several solar weeks of effort by Corax, Chief Apothecary Vincente Sixx, and Magos Genetor Orlandriaz, a breakthrough was achieved, and a new reservoir of stable Astartes gene-seed was extracted from the primarch DNA. The gene-seed was more pure than "normal" Raven Guard gene stock as it came from undiluted primarch DNA before it was broken down into the 20 different recombinant strands that gave birth to the individual primarchs. It was implanted using an extremely accelerated development schedule within 500 aspirants, with excellent results. The resulting Astartes, though lacking combat experience, were even more capable than typical Raven Guard Space Marines. However, the traitorous Alpha Legion had other plans for the shattered Raven Guard. Patiently waiting until the Raven Guard had achieved the genetic breakthrough, they were fomenting rebellion among the old tech-guilds of Kiavahr, the Forge World that the moon of Deliverance circled, while assembling an Alpha Legion force nearby, and simultaneously misleading both their nominal allies amongst the other Traitor Legions and their supposed allies in the alien Cabal about their true purpose. With the help of adepts from the Dark Mechanicum, the Alpha Legion operatives within the Raven Guard contaminated the pure primarch gene-stock held by the Raven Guard with a virus that was tainted with Daemonic essence. The nature of the virus was unknown to the Alpha Legionaries until after the gene-stock had been contaminated, as their Dark Mechanicum allies had insisted the virus could be easily extracted once the primarch gene-stock came into their possession. The next cadre of 2,000 accelerated Raven Guard Astartes was predictably a disaster. All manifested hideous Warp-related mutations after they were implanted with their gene-seed organs, and many had to be kept imprisoned. The primarch DNA and all information about it was secured by Omegon, who had been secretly on Kiavahr the entire time, manipulating events as needed. Yet the outright destruction of the Raven Guard's remaining gene-seed stock was prevented by the Raven Guard mutants, who were tasked by the dying Chief Apothecary Sixx to save the future of the XIX Legion.
  • Magos Xenologist Erlan Klute - Erlan Klute is a senior Magos Biologis who has devoted his service to the destruction of the Tyranid threat ever since it was first encountered. Erlan devoted a large amount of his life to studying the works of the well respected Magos Varnak, the first Tech-priest to have identified and observed the creatures of Hive Fleet Behemoth on the world of Tyran. Klute and his peers seem motivated by a xenocidal hatred, their mechanically-augmented hearts burning with the heat of the forge. The so-called "Circle Varnak" has pursued the destruction of the Tyranids ever since the fall of Tyran. Widely spread across the Eastern Fringe, these few individuals work tirelessly against the Tyranid threat. Klute has been active in the Jericho Reach region for just over four standard years, having arrived just before Hive Fleet Dagon first appeared in the Reach.


  • Battlefleet Gothic Rulebook, pp. 92, 123
  • Dark Heresy: The Inquisitor's Handbook (RPG), p. 155
  • Deathwatch: The Jericho Reach (RPG), pg. 223
  • Rogue Trader: Into the Storm (RPG), pp. 82-83
  • Deliverance Lost (Novel) by Gav Thorpe