"In the sunless body of our Hive, the flock of the faithful grows. We are guided by our Great Father's sacred vision, protected by his loving hands. Within these holy shadows we dwell, while the impure bathe in spire-top starlight. And what lies between those stars? What sails beyond those distant suns? Shrouded in night, borne within that eternal black: Our redeemers, our Gods -- truer than the silent, long-dead Emperor -- the Children of the Void. We hear them in our dreams, we feel them in our blood. They call and we will answer. We will rise and claim the engines of labour that have bound us in servitude. This world will burn. It will be cleansed, purified, made ready, and the Heavens will deliver our reward!"
—Unknown Genestealer Cult Magus
Genestealer Cultists rise

An army of Genestealer Cultists turn their guns against the Astra Militarum


A display of the standards used by various Genestealer Cults from across the galaxy

A Genestealer Cult is a xenos-worshipping secret society made up of and controlled by Tyranid Genestealers that thrives in the dark corners of the Imperial underworld across the galaxy. Secretive, stealthy, and utterly malignant, Genestealer Cults are the cancers growing unseen in the hidden spaces of Mankind's realm. Some cultists are truly monstrous, skulking along dank tunnels with robes or hessian sacks covering their hybrid xenos anatomies. Others are merely pallid and bald, able to pass for loyal Imperial citizens whilst their wyrm-form tattoos remain hidden. These latter-generation brethren mingle amongst the herd of Mankind like wolves in sheep's clothing, working so hard amongst the crumbling machineries of Human industry that none spare them a second glance -- but under their work fatigues and rough miner’s apparel, they all bear the mark of the alien.

Once their brotherhood becomes strong enough, and all is in place for their great uprising, the Genestealer Cult will make its play. The militant throng boils by the thousand from sewers, tunnels and basements, seeping from the spires high above like insects pouring from a hidden nest. On this darkly glorious day of war, the cult's warriors are already ten steps ahead of the enemy. Saboteurs have shattered the supply lines of those who would oppose them, hidden agents have assassinated key commanders, and routes of escape have been cut off by demolition crews and blast teams. Every eventuality the cult's masters could foresee is accounted for, every advantage stacked in their favour. The enemy find their ammunition crates empty, their fuel reserves dry, their transport craft hijacked and their supporting fleet holed and listing in orbit. When the cult attacks, the enemy is already surrounded, stranded and half-beaten, ripe for a slaughter long-planned.

The butchery the cult metes out upon its enemies is terrible indeed. Though the greater masses of these hordes are armed little better than planetary militia, their sheer numbers and fanatical devotion make them a fierce prospect in a firefight. High-level threats will be ambushed -- not only by mutant hybrids that hiss and shriek as they lay about themselves with weapon-like mutations, but also by the Purestrain Genestealers of generations past and present.

The commanders of the enemy force are met in battle by the leaders of the cult -- the Primus, an inspirational war leader; the Magus, a hypnotic telepath; and the Patriarch itself, a monstrous terror that crossed the vastness of space to bring disaster to the world. In truth, the cult is in thrall to a far greater power. Unseen and utterly beyond comprehension, this inevitable force, this Great Devourer, is drawn to the prey world by the very cult that seeks to conquer it. When the doomsayers of this dark dynasty cry that the end of the world is nigh, their claims are more accurate than even they imagine.


Ghosar Quintus

The first confirmed Imperial engagement with a Genestealer Cult occurred upon the mining colony of Ghosar Quintus in 680.M41. Investigating what appeared to be a perversion of the Imperial Creed, Inquisitor Chaegryn led a team of Tempestus Scions to Ghosar Quintus and ventured into the depths of the Great Pit. The deeper Chaegryn ventured, the more evidence of deviance he found. Strangely, his last communiqué stated that all was well, and that the Trysst Dynasty that ruled Ghosar Quintus should be left to its own devices.

It was a full standard year before Chaegryn's fellows in the Holy Ordos of the Inquisition noticed that something was deeply wrong. A five-man Kill-team of Deathwatch Space Marines was sent on a follow-up mission of lethal investigation, yet they too were swallowed by the mysteries of the Great Pit. Only when the steel-willed Chaplain Ortan Cassius mustered his own hand-picked Kill-team was the vile truth unearthed -- Ghosar Quintus was home to a xenos infestation.

Kill-team Cassius fought through hundreds of Genestealer Cultists as they plumbed the depths of the Trysst Dynasty's corrupted world. Though they made it out alive, the Space Marines were changed forever by the gruesome ordeal. Most shocking of all was not the Genestealer Patriarch that lurked at the heart of the cult, but the damning evidence in the mining cult's shipping holographs. Under the guise of industry, the xenos-tainted Trysst Dynasty had spread its curse across not only the Ghosar System, but throughout the sector. The implications were staggering.

The Hidden Dynasties

Only those Imperial operatives of the highest echelon have an inkling of how far the Genestealer Curse has spread across Mankind's realm. For every Cult that has been thrust into the light, whether by its own ascendancy or by the burning fires of extermination, there remain a dozen hidden in the dark spaces of the galaxy, waiting for their moment to strike.

  • The Pyropurge (Date Unknown) - The Pyropurge of Jauseth Septima is thought to be exhaustive. Using psychic means, the Puritan Inquisitor Dethrec Balthagar and his Deathwatch allies root out every last trace of Genestealer infection on the planet. However, a fourth generation cultist with the germ-seed of the alien left the infected world three solar weeks earlier aboard a cryopod shuttle, and he later returns to his home planet. Within three standard years of Inquisitor Balthagar's death in service, Jauseth Septima is overrun once more.
  • The Infested (Date Unknown) - The capital world of New Gidlam falls to the Hivecult. The underworld brotherhoods first take over the lower portions of each teeming hive city, then infect the Imperial aristocracy that live a privileged life in the spires above. The gangs that have carved out territory in the lower levels fight to the last bullet, uniting as one in the face of the greater alien threat, but are eventually overcome. New Gidlam’s principal human exports -- skilled roachworm silkers and recruits for the Astra Militarum -- spread the infection of the Hivecult from the outworlds of the Imperial domain and into its heartlands. Before the decade is out, the largest Hive World in the Segmentum Solar is assailed by the burgeoning Genestealer Cult, and the cycle of war begins anew.
  • Death In the Jungle (Date Unknown) - Moraz III, a Death World swathed in carnivorous jungle flora, is struck by the wreckage of a Rogue Trader's menagerie-ship. The Genestealer that breaks free from the ship's hold infects the local populace, giving rise to the nascent Cult Veridian. However, every member of the dynasty is killed when a regiment of Catachan Jungle Fighters uses Moraz III as a training world for their hunt-and-slay tactics. Only the Genestealers escape. Once the Catachans have left the planet, the xenos emerge once more, swiftly becoming the alpha predator of the jungle and reclaiming Moraz III for themselves.
  • A Doom Unstoppable (Date Unknown) - A strike force of Black Guardians from Craftworld Ulthwé descends upon the gyroscopic space station of Delugen. The prophetic Farseer Anathroelle Starseeker leads her warriors into Delugen's corridors. There they slay the Cult Tendricul in the most thorough fashion, putting every human they find to the sword. The station's astropathic distress signal reaches a Black Templars fleet, and whilst the Eldar are rooting the last of the humans from the station's corridors, the Boarding Torpedoes of the Space Marines strike home. The Ulthwé Eldar are driven off, and the last few survivors of Delugen escape. Within a standard year, the symbols of the Cult Tendricul are seen on a dozen planets, including the Eldar Maiden World Virgose.
  • The Vitria Strike (Date Unknown) - Evidence of Tyranid infestation is uncovered upon the glasscrete world of Vitria. A platoon of Kappic Eagles takes battle to the Genestealers lurking within the shattered pane-habs. They engage the xenos broods in a battle that culminates in a desperate fight against a Tyranid Lictor. The beast is slain, and its lair examined in detail. Its walls are covered with doomsayer ravings -- phrases daubed in blood telling of numberless killers from beyond the stars, of death made flesh, and of a "Great Devourer." Amongst them was a single word repeated over and over -- "Cryptus."
  • A Single Seed (Date Unknown) - The wreckage of the freighter Pegasine, destroyed by the Lance strike of an Ordo Xenos corvette, spirals through the skies of the frontier planet Hopefoster. Most of the debris burns up on entry, but the largest section lands more or less intact. After long solar weeks spent healing, a single Genestealer survivor awakens in the wreckage. It becomes the Patriarch of the Voidbrood, and after a Terran century of unfettered expansion, its cult rises up to overrun the planet entirely.
  • The Last Hierarch (Date Unknown) - Robbed of both its Patriarch and Magus after a pinpoint strike by the Imperial Navy, the Cult of the Star Saviours misreads a week-long meteor shower as a sign of imminent salvation. Taking the shooting stars in the skies of Evergrind as confirmation that celestial rapture is close at hand, the last Hierarch, Primus Adamant, puts into motion his plans of conquest. On the night of the grand insurrection, every breeder city and dust farm upon Evergrind's surface is lit by the fires of revolution. The cult's ascendance is like a flame to dry tinder. Riots break out in every quadrant as the local citizens take the opportunity to loot, kill and burn, taking revenge for endless centuries of oppression by their taskmasters. During the fighting, Primus Adamant is slain by an entrenched heavy weapons team. By the time the new moon rises, the planet has devolved into a post-apocalyptic bedlam populated by warring tribes, lone scavengers and scuttling half-xenos predators. Those craft foolish enough to make planetfall upon Evergrind are soon brought low and claimed by the leaderless and atavistic cult -- and the ships' passengers with them.
  • The Gnarling (Date Unknown) - Upon the Forge World of Ecovoria, the spider-like figure known only as the Gnarling becomes a popular bogeyman used to scare the manufactorum caste's children into obedience. Tragically, a kernel of truth lurks in the legend of a subterranean monster clad in a cloak of human skin. Ten generations after the first grand-mamzel tells her wards the Gnarling will steal them away, giant sinkholes appear across Ecovoria -- the secret tunnels burrowed under each forge complex were so extensive that entire portions of the planet’s crust fall away. Black-limbed Genestealer Cultists boil out of each underground warren in impossible numbers, first ripping apart the Skitarii maniples sent to quarantine each sinkhole, then attacking the wider populace. Through the carnage stalks the Genestealer Patriarch that gave rise to the Gnarling myth, the leathery devotionals tied to its spine billowing in the winds of open war.
  • The Greater Good Corrupted (Date Unknown) - A lone Genestealer from Hive Fleet Gorgon reaches the Tau Sept World of Ksi'm'yen. The creature is captured by the planet's Earth Caste scientists and subjected to extensive analysis, resulting in a lowly worker being implanted with a measure of germ-seed. The grotesque anatomies that spring up in the laboratories are seen as curious rather than blasphemous by the ever-inquisitive Earth Caste, for the Tau approach to alien life forms is founded on the concept of acceptance and tolerance. When the research divisions experience a bloody schism twenty Terran years later, the Fire Caste are called in, only to find many subterranean research facilities overrun. Ksi'm'yen is consumed by war, and quarantined for almost ten Terran years before the eccentric Ethereal Aun'ghol declares it productive and clean.
  • The Sin of Damnation (589.M41) - Sergeant Lorenzo -- a gifted Blood Angels tactician –- leads two squads of Terminators to board the Sin of Damnation. Within that legendary Space Hulk the Blood Angels erase the shame of their Chapter's former defeat, releasing a poison throughout the behemoth that kills the tens of thousands of Genestealers slumbering in void-hibernation within its cavernous recesses. In doing so, the Space Marines prevent the vanguard organisms from spreading across the stars, eradicating thousands of potential cults before they have a chance to spawn.
  • Xenos War (Unknown Date.M41) - A Genestealer Cult rises in the shadows of the Octarius Sector's Scrapworld Dakka. The Orks of Mount Mekaniak are impressed by the massive Gargant Clawbeast, a purple monstrosity of beaten metal built with six limbs. When the Vostroyan Firstborn descend to kill the planet's ruler, Gurnmek of the Iron Fist, Clawbeast is deployed to terrifying effect. The Vostroyans send in whole companies of Devil Dog tanks to carve up the Gargant, and succeed in stopping it in its tracks -- until the Gargant's great belly hinges open, spilling hundreds of Genestealers into the ranks of the Astra Militarum. They tear open the tanks and feast on the fleshy bounty within.
  • The Spawn of Cryptus (998.M41) - Soon after the Kappic Eagles' mission report from Vitria reaches the Commissariat, the Cryptus System is reinforced by Cadians, Sisters of Battle, and the Militarum Tempestus. The area known as the Shield of Baal -- that cordon of space that protects the homeworld of the Blood Angels Chapter -- is placed on a war footing not a moment too soon. The warnings found on Vitria prove prescient -- tendrils of Hive Fleet Leviathan reach out to consume every living thing in the overpopulated Cryptus System. As soon as the Leviathan splinter fleet's innumerable Bio-ships pass through the icy shield of the Aegis Diamando, the corruption upon the capital world of Asphodex is revealed. The ruling family of Asphodex's principal metropolis has long been corrupted by the towering Genestealer known as the Spawn of Cryptus, and its aristocracy work to undo everything the Astra Militarum has achieved. When a Blood Angels fleet from the neighbouring Baal System arrives to bolster the increasingly desperate defenders, Captain Arenos Karlaen of the Archangels leads his brothers under the city in a series of escalating battles that eventually sees the Spawn of Cryptus slain and its vile brood scattered to the stars.
  • Infestation and Plague (ca. 998.M41) - The Genestealer Cult Tenebrous finds itself becoming the infested, rather than the infesters, when their bulk lander is swallowed by a Warp Storm that strands them on the outskirts of the Garden of Nurgle in the Realm of Chaos. The Cult discovers the true meaning of parasitism and horror. Eventually, the Grandfather of Plagues allows them to emerge into realspace once more, horrifically changed and ready to serve their new master's sickly agendas.
  • Shadow of the Leviathan (ca. 999.M41)- Reports of a new and mighty Hive Fleet emerge -- not from one prime sector, as with Hive Fleets Kraken and Behemoth, but a dozen at once. A wave of insurgencies rises up across the Segmentum Solar. Hundreds of Genestealer Cults reveal themselves in the space of a single Terran month. The Deathwatch, spread too thin to halt these unforeseen conquests, seek help from the wider Adeptus Astartes -- but to no avail.
  • A Deathly Gift (ca. 999.M41) - On the Agri-World of Cornucopia, a splinter fleet of the shattered Hive Fleet Behemoth triggers the rise of the Genestealer Cult known as the Starchosen. The Ultramarines 8th Company put down the insurrection at great cost, its massed Assault Marines taking their Chainswords to the Genestealers and their kin until none are left alive. Planetary Governor Udo Ingloriam sends a cargo ship full of brand new Goliath trucks to Masali, Cornucopia's twin Agri-World within Ultramar's borders. Only after the vehicles are found to be full of Genestealers, sealed within antique stasis caskets to prevent detection, is Udo Ingloriam's treachery uncovered. The 8th Company returns to Cornucopia. This time, it is all but destroyed, for the Starchosen have grown strong indeed. On the orders of Chapter Master Marneus Calgar himself, the planet is designated Perdita and subjected to Exterminatus.
  • The Wyrmslayers (999.M41) - A Genestealer Cult calling themselves the Wyrms of the Ur-tendril are discovered by Ordo Xenos agents, entrenched amongst the Nordafrik under-archives on Terra. Adeptus Custodes Captain-General Trajann Valoris refuses a request by the Deathwatch to send Kill-teams against this threat, instead leading the purge in person at the head of a huge Adeptus Custodes Shield Host. The Cult put up a brutal fight, their sheer numbers and fanaticism allowing them to drag down one Custodian after another and tear them limb from limb. Yet for every one of the Custodians that falls, hundreds upon hundreds of malformed cultists and Aberrants are slaughtered. At last, Valoris himself beheads the monstrous Broodlord that ruled over the cult. He orders the creature's disturbing inner sanctum burned despite the protests from the Ordo Xenos investigators -- Valoris refuses to let anyone other than his comrades witness the foul mural that decorates the sanctum's back wall, of a nest of fanged tendrils emerging from the heart of Sol itself to devour Terra whole...



A pack of Genestealers leaving a fallen spacecraft

Genestealers are vicious and frighteningly intelligent alien lifeforms. They are largely independent, capable of surviving alone for standard centuries. When encountered as part of a brood, however, a gestalt psychic will binds them to one purpose. Originally encountered upon the moons of Ymgarl, long before Hive Fleet Behemoth breached the Imperium, these beasts were once thought to be an entirely separate species to the teeming hordes of the Tyranids. Only when the Ordo Xenos conducted a harrowing program of investigations did they realise the truth -- that the Genestealer was a vanguard creature of the encroaching Hive Fleets, and that the Ymgarl genus was but one example of the forms it could take.

Genestealers are carried from world to world much as a virus is carried from host to host –- unseen and unbidden. Their physiques are so hardy that they can even survive in the cold vacuum of space. There are scattered reports of armies of these xenos creatures emerging from honeycombed asteroids and torn-open ghost ships. The most severe Genestealer infections have been traced to Space Hulks, vast conglomerate voidships that drift across the galaxy on the etheric tides of the Warp -- on such behemoths Genestealers have been found not in twos and threes, but in their thousands. More commonly, small broods of Genestealers stow away upon the voidcraft of Humanity's endless armadas. Able to fold their gangling physiques into relay pipes and crawlspaces, they can hide in even the smallest shuttles, entering a hibernatory state until they emerge from their sojourn to sow the seeds of destruction anew. Many a bulker transport has arrived at its destination carrying a lethal cargo indeed.

When a Genestealer reaches a world ripe for infection, it will clamber into the dark and forgotten spaces of a populous area, lurking unseen as it prepares to spread its influence. As with all their voidborn kind, the Genestealer is inhumanly patient, able to subsist on very little sustenance and to wait for Terran decades if necessary before making its move. Once it is certain of being able to acquire victims whilst remaining undetected, it will begin to abduct them and implant them with its alien blight to make them unwitting hosts of a new generation of terror.

A cult can start with but a single organism. Should a lone Genestealer reach an inhabited world, it will immediately go into hiding, emerging only on the blackest of nights. Those who fall prey to the Genestealer's silent ambushes are not torn apart for later consumption, as with most victims of the Tyranid race, but instead put in thrall by its hypnotic gaze. They are then impregnated with a portion of the creature's own biomass, delivered under the skin via a ribbed tube called an ovipositor. This process is known as the "Genestealer's Kiss." The resultant parasitism alters the infected's body until the xenos taint runs throughout. It also alters the mind, forcing the victim through a bioneural psychic connection to revere the Genestealer as a messianic figure, the idol of an obsessive new religion.

Whenever a Genestealer implants a victim, a horrific birth will soon follow whenever that individual, whether male or female, breeds with others of its species. The resultant Genestealer hybrids are grotesque and misshapen creatures that are as varied in form as they are hideous to behold. Certain features are common, such as bulbous craniums and snarling, needle-toothed maws, a pair of extra limbs ending in viciously sharp claws, truncated tail-spikes and mottled, purplish skin. These initial hybrids are known as the First Generation.

The hybrids of the First Generation will reproduce with newly-hypnotised members of the cult, who sire young in their turn. This gives rise to the Second Generation. These new creatures are hunched and stooped -- not in the manner of the old or infirm, but more like pressured springs that are ready to explode into sudden movement. These hybrids may have five or even six limbs, but their eyes and mouths are like those of their human parents, and they can make themselves understood in Low Gothic. Though their minds are still so alien that they defy analysis, the Second Generation is sapient enough to understand its host society. Some are even put to work in the industrial brotherhoods of their kin, their uncanny strength and resilience allowing them to use heavy mining tools and explosives with far more ease than a human operative.

The Genestealer Curse

Genestealer Cultists

The many generations of Genestealers within a Genestealer Cult

Purestrain Genestealers propagate with a hideous alien fecundity, infecting generations of Imperial prey until the time is ready to strike. Each new batch of offspring descended from a single Genestealer Patriarch seems more human than the last as the xenos germ-seed is seemingly diluted, but within, the shape of the beast lurks unchanged. At the culmination of the curse's cycle, alien nightmares are born anew.

As each cycle passes, the hybrid offspring evince fewer and fewer mutations from the human or other host species' genetic baseline. The Third Generation is typified by an upright stance -- though they appear human from a distance, on closer inspection they have heavily-ridged heads, mauve to violet skin, and may even hide a vestigial limb under their clothes. By the Fourth Generation, the scions of the Genestealer Cult can pass for fully human, inveigling themselves into positions of power to further the aims of the cult. Leaders of uncanny influence emerge within the hidden cult hierarchy -- psychic magi and charismatic demagogues whose rhetoric inflames the subculture further.

Fourth Generation cult members can breed true. They do not give birth to untainted humans, but instead to Purestrain Genestealers just as alien as the original progenitor of the cult. The parents of these Fifth Generation creatures see them not as the hideous, hissing changelings they truly are, but as soft-skinned infants, innocent and sweet. They do everything they can to protect them, even giving their own lives if necessary. By this point, the curse's hold upon the dynasty is complete.

The Genestealer at the heart of the cult, known as the Patriarch, has an inherent psychic control over every one of these minions, no matter the generation. The Patriarch unites them in a single sentience -- a gestalt consciousness known as the "Broodmind" akin to the far larger Tyranid Hive Mind. It is this shared sentience that makes the cult so tight-knit and loyal, that gives them uncanny strength and speed in battle, and that seeks to undermine the spiritual sanctity of Mankind. Such xenos cults have thrived in the dark corners of the Imperium longer than any suspect. On those occasions when they rise up in open rebellion, they can capsize a planet's defences in a matter of solar hours. 

The cultists of these grand insurgencies have spent their whole lives preparing for the day of the final conquest. Generation after generation have been bred in secrecy, cycle after cycle bearing nauseating fruit. The infected have spread the curse to others, and to their children, who in turn have infected more. Like a living virus, they breed exponentially, their numbers swelling until the rulers of the society's underworld are strong enough to seize the entire host planet. Though the later generations of each cycle have the appearance of common men and women, inside they are xenos through and through. Their allegiance is owed only to the organisms that brought the Genestealer Curse to their world, and the hybrids of their hidden kindred. Their Patriarch, starborne and inhuman, squats at the centre of a web of influence that expands until it covers the entire world. Every soul in the cult is mindlessly obedient to this repulsive creature, and would give their lives to save it.

Generation 1

The first of a cult's vile children, a First Generation Hybrid is as much of a monster as it looks. More reminiscent of a Genestealer than a man, these foul creatures feature between five or six limbs, each one ending in sharp talons. Their bulbous heads have the facial features of their xenos gene-father, with their skin taking on a purple hue. These creatures are little more than beasts, their instincts directing their every move.

Generation 2

The second generation of Hybrids are hunched and stooped -- not in the manner of the old or infirm, but more like pressured springs, ready to explode into movement. Like the generation before them, Second Generation Hybrids may have five or six limbs, but their eyes and mouth are more like their human parents, and they can make themselves understood in Low Gothic. Though their minds are still so alien that they defy analysis, they are still sapient enough to understand their host society. Some are even put to work in the industrial brotherhoods of their kin, their uncanny strength and resilience allowing them to use heavy mining tools and explosives with far more ease than any mere human.

Generation 3

Taking a fully upright stance, the Third Generation Hybrid is reminiscent of many mutants in Imperial society. Their foul features go unnoticed in the underhives of many Imperial worlds. However, on closer inspection their alien form is revealed. They have heavily ridged heads, mauve to violet skin, and may even hide a vestigial limb under their tattered clothes.

Generation 4

By the fourth generation, the scions of the Genestealer Cult can pass for fully human, inveigling themselves into positions of power to further the aims of their sinister cult. They are often noticed by their human overseers as dutiful, hard-working citizens, and as such, often find themselves above suspicion. Many of these hybrids join the Astra Militarum to spread their vile seed across the galaxy, starting new cults and claiming worlds for their four-armed Patriarch.

The Creation of a Cult

The genesis of a Genestealer Cult is a strange and disturbing process. Though it obeys a loosely cyclical structure, many offshoots and bastardisations occur, resulting in a spectrum of anatomies from the outwardly wholesome to the truly bizarre. All members of this tainted family tree -- even the non-hybrid members, known as the Brood Brothers -- remain fiercely loyal to one another, bound as one by the gestalt psychic Broodmind.

The most powerful weapon of the Genestealer Cult is secrecy. From the moment the infection vector arrives to the grand uprising itself, the faithful stick to the shadows. Those elements that emerge into the light of everyday life wear a mask of mundanity; outwardly, its cultists worship the same deity as the host civilisation, albeit a strange variant thereof. They teach extreme modesty, keeping their mutations hidden under robes and industrial clothing. Latter-generation hybrids work tirelessly, respecting the old and cherishing the young. Only on the day of reckoning is the awful truth of their existence revealed.

A Parasitic Order

Those cults unearthed by the Inquisition have a common hierarchy, largely dictated by the generations and cycles of xenos infection. Though variations occur, the Patriarch is analogous to the monarch of this kingdom, with the Magus as his grand vizier and the Primus the leader of his holy crusades. The dynasty that serves them can number in the millions.

Every iteration of the Genestealer infection can spread anarchy and disaster. Better known as brood cycles, the mockeries of family lineage that form the framework of each cult are all slaves of the Patriarch's greatness. To celebrate his magnificent strangeness by echoing his form is a privilege like no other. Though all pay homage to the Patriarch. Each brood cycle has a strong internal coherence, and many will bear markings that bind them further to their brethren within the cult.

Though the broods of each cycle are similar in organisation, the Genestealer Curse does not conform to the strictures of mortal science. Anomalous bioforms rise to the surface with every new generation, for interbreeding within the cult is common, and Tyranid gene-matter is, by its very nature, highly mutable. Even as the second and subsequent cycles spread the infection anew, the original brood cycle will still be active, casting the web of the Patriarch's influence ever further.

The Cult of War

Cult of War

A Genestealer Cult ambushes the Space Marines of the Howling Griffons Chapter

From the moment the first hybrid is born, the cult begins preparing for a world-spanning war of insurrection. There are other factors that can trigger a large-scale military intervention, sometimes before the dynasty reaches critical mass. Woe betide those who derail the cult's master plan, for its warriors strike serpent-fast, and their vengeance is terrible.

Genestealer Cults are concerned with their own propagation above all, and will usually only commit to an armed action on its own terms. There remain exceptions, of course, for in the crumbling edifice of the Imperium, even the most watertight plans do not last long in practice. Each ruction, setback or disaster is handled in its own fashion. On occasion, an incautious power-grab or roving aberration may lead to the cult being investigated by Imperial authorities. If an inquest from the Adeptus Arbites -- or worse still, the Inquisition -- cannot be dealt with by a visit from the Magus or his minions, the cult may soon find itself under attack by anything from a regiment of Militarum Tempestus soldiers to a strike force of Deathwatch Space Marines. Though this calibre of attack can eradicate a Genestealer Cult in a scouring that shakes the underworld to its core, all it takes is for one Tyranid lifeform to escape and the cult can begin anew. 

The Cult's Primus, being a war leader, has a more aggressive approach to the propagation of his kin. He will gather a hand-picked army from the parent Cult, and then strike out to claim new worlds in the name of the Patriarch. Often this is done under the guise of industry, making use of existing space lanes and import routes to carry a host of Genestealer Cultists to a new planet. In the darkness of the cargo holds, shipment auto-crates will hiss open, and the Primus will lead his brethren forth. Should their incursion be uncovered, the cult will strike with swift and overwhelming force. If their assault does not take down their new adversaries in short order, they will scatter like oil-roaches in torchlight, seeking shelter in the dank corners of their new domain before later regrouping. 

There are times when a host planet is attacked by outside forces -- perhaps the target of a Hrud migration, a xenos pirate raid, a Greenskin WAAAGH! or even a Warp breach. Most cults, nestled in hiding, will be content to wait for the storm to pass. But if the invasion directly threatens their interests, they will fight like a hive of angered hornets to defend them. Such planets teeter on the brink of catastrophe, rescued from one alien warhost only to find their saviours embody another, far more sinister threat.

Should all go well, the cult will wait with the patience of spiders for their moment, generation after generation spent in preparation for the final battle as they infect ever more territory. Once all is in order, the intricate web of secrecy is finally torn away, and the world is plunged into anarchy.

A Military Dynasty

An Astra Militarum regiment stationed upon a prey world will slowly become populated by humans who bear the hidden mark of the Genestealer within their anatomies. Soon enough, the regiment inducts new recruits with a certain strange cast to their skin, bulbous craniums and strangely pointed fingers. Within an armed force that recruits such divergent strains of Humanity as Ratlings and Ogryns, mild variations of appearance are often overlooked –- especially when the cadets in question are so efficient and obedient. As the generations pass, it is common for the infiltrating members of that world's cult to be grouped together into the same platoons. Sometimes they are recruited in such numbers that entire regiments are taken over. Such infected military organs take pains to stay incognito, and as such, have only a rudimentary presence in the Imperium's armed forces and do not boast the wealth of munitions and war machines that a proven element of the Astra Militarum might enjoy. Still, even a basic military presence on a cult's host world is an asset beyond price. On the day of insurrection, those Astra Militarum platoons seeded with the agents of the cult will reveal their true allegiance. Eyes alight with fanatical fervour, these wolves in the fold finally put their treacherous plans in motion, launching deadly surprise attacks upon their fellow regiments before joining the main body of the cult. In an institution as immense and diverse as the Astra Militarum, a force as cunning and sly as a Genestealer Cult can thrive for many standard years before the horrible truth is revealed.

The Hive Fleet Descends

Tyranids descend

A Genestealer Cult awaits its salvation as a Tyranid Hive Fleet descends upon a ruined Imperial world

As a cult pushes its tendrils ever further into its host civilisation, it prepares for the day of its great ascension. Though it may be standard decades, even centuries in coming, sooner or later a psychic shadow will fall upon the star system in which the cult has spread. This is the Shadow in the Warp, the first sign of the utter despair to come. At first, the strange penumbra of this influence sends soothsayers mad and inspires wild panic in those who channel the energies of the Warp. The Astronomican at first becomes dim, then shrouded completely by the psychic miasma crawling across the stars, cutting the star system off from the rest of the Imperium so it becomes all but impossible to send reinforcements. Only then does the source of the threat emerge from the darkness. Starlight glints from a flotilla of celestial bodies, visible as a shoal of dots in the night sky. While these bodies may appear beautiful at first, their surpassing ugliness becomes more evident as they draw close. This is a bio-fleet of the Tyranid race, and it has come not to enlighten, but to devour.

The cult sees the arrival of this impossible menace as the long-awaited fulfilment of their prophecies. They believe the Patriarch’s kin, unfettered by Humanity's failings, are here to elevate the faithful and lift them into the light forever. The skies cloud over, thickening with xenos spores as the Hive Fleet prepares the cult's world for consumption. Enraptured, the cult's true believers tell each other that it is always darkest before the dawn. Celebrations and warlike shouts ring through the streets as their devotional frenzy reaches new heights. When the Tyrannocytes rain from the sky like fleshy meteors, the cultists wave their banners high, hoping to attract the attention of the angelic host. 

As the giant brood-sacs of the bio-ships split open to disgorge shrieking, blade-limbed war-beasts, a seed of doubt worms into the minds of the cultists. Still, their belief in the notion of star-borne saviours is so ingrained they keep fighting against the wider populace. The Tyranid invaders mass together into a tide of chitin and fang, surging over the lands to cut down or consume the indigenous populations. With the Hive Mind guiding each brood, the Tyranid hordes do not see the cultists as prey; in fact they are ignored at first by the synapse creatures coordinating the attack. For a short and blissful period, cultist and Tyranid fight on the same side. Once their adversaries have been slain, the cultists become eager to embrace their distant relatives in celebration, jubilant that their star-spanning family is at last complete. They walk forward, arms wide, into the seething avalanche of weapon-forms. They too are torn limb from limb. Only then does the true magnitude of the cult's folly hit home. The mood of the cult swiftly changes from dogged loyalty to panic.

The final revelation comes both from within the cult and without. Those the cultists once adored turn upon them in the worst of all possible betrayals; any who seek succour from the Patriarch instead go to their doom. With its sentience subsumed by the greater Hive Mind, the creature becomes just another Tyranid, another nameless cell in the void-crossing super-organism that wants nothing less than to devour the galaxy. As soon as the planet's defenders are overcome, the Patriarch and its brood will attack their own, wicked claws punching into close advisors and trusted minions, who die choking on their own disbelief. Those Purestrain Genestealers spawned upon the host planet attack their devoted parents without hesitation, slaughtering them in a flurry of talons and snapping mouths. Those of the cult who somehow survive this grim twist of fate flee as best they can, but they do not get far. The hail of Tyranid spores intensifies, and the planet itself is altered on a molecular level, becoming a noxious hell. Alongside the bodies of the wider populace, the corpses of the cultists are devoured and regurgitated into the acidic digestion pools that bubble upon its surface. There, they are dissolved into a sickening gruel, raw biomass that is sucked up by ribbed capillary towers into the bio-ships high above. So it is that the host population and the cult's parasitic reflection are made whole at last, their bodies mingled in the final act of this apocalyptic tragedy.

Forces of the Genestealer Cult

The Patriach


The Genestealer Cult's Patriarch during a meal in its hidden subterranean lair.

Lurking at the centre of the Genestealer Cult's web of lies is the Patriarch, father of a hidden dynasty. Twice the height of a Space Marine and with strength enough to slice an Ogryn into bloody chunks, this creature is a leering nightmare of tooth and claw. In a flurry of whipping limbs and diamond-hard talons the Patriarch can tear through platoons of heavily armoured warriors and even light vehicles. Yet it is the hypnotic spell with which it binds its chosen hosts that mark it out as perhaps the most dangerous Tyranid yet encountered by the Imperium. The uncanny powers of the Patriarch make it a fearsome puppet master, a threat so pervasive it has a xenocode threat designation unto itself. By spreading the Genestealer Curse, this creature is capable of destroying not just warriors and war machines, but entire worlds.

Like the monarch of a dark underworld, the Patriarch squats in its lair, glowering and licking its claws in anticipation of the day when it will rise up to make every sentient creature on the planet its devoted gene-slave. Once, the beast was but a Genestealer, likely one of an identical brood and no more remarkable than any of the uncounted billions of such organisms abroad in the galaxy. Once cut off from the Hive Mind, a new genetic imperative takes over. Upon reaching its prey world, perhaps as a stowaway on some nameless freighter or piece of stellar debris, the nascent Patriarch creeps from its vector vessel into the darkness of its new domain. There, it learns of the planet it has taken as its home, and abducts the first of its victims. With the Genestealer’s Kiss, the monster becomes the first of its brood to bestow its foul legacy upon a native host. In this rapacious action, it takes the first step to becoming a Patriarch.

As the strange alchemy of the alien's life cycle takes hold, that first creature to infect a host on a new planet grows ever larger and more potent. Much as an alpha simian becomes heavier and grows outward signs of dominance to mark its ascendance, the Patriarch's body bulks out, its claws lengthening until they are more like bony sabres than simple talons. The creature's mind develops too, filling with strange telepathic energies until its engorged cranium bulges fit to burst. At first, its instincts are only to survive and to procreate, and its abilities develop accordingly. Eventually, however, the Genestealer's uncanny ability to enthrall its prey burgeons into a suite of telepathic abilities that can bind a person to its service with but a flicker of its cold, inhuman eyes.

To gaze into the eyes of a Patriarch is to gaze into the void and feel a fraction of the Tyranid Hive Mind staring back. One who faces such terrible power realises that he is no more than a speck of cosmic dust adrift in an uncaring universe. His shattered mind is then easily bound -- he will accept the Patriarch as the harbinger of an irresistible new order or be driven to insanity, his doomsayer rantings those of just another madman broken by the endless grind of Imperial life. Those few individuals strong-willed enough to resist the Patriarch's psychic dominion might raise a hand or blade to strike it, but this will invariably be their last act before the beast rips them limb from limb.

The Magus


A Magus of a Genestealer Cult uses his psychic powers to direct his kin during a rebellion

The Magus of a Genestealer Cult is psychically gifted and possessed of a supernatural charisma. His control of the Genestealer hybrids around him is total. As the prophet of the Patriarch, the word of the Magus is law, and his telepathic abilities are more than powerful enough to enforce it. Yet for all his presence and mental skill, each Magus is no more than an extension of the Patriarch's will, just as the Patriarch is an embodiment of the wider Hive Mind.

The cult's Magus is its foremost link to the world of men. Should the dynasty find its expansion stymied by a Planetary Governor or strong-minded rival, a Magus may well visit the obstinate individual in person, using honeyed words and psychic powers to either force his obedience or convert him to the cause. In moments, the deed is done, and the Cult has a highly-placed agent instead of a difficult adversary. 

A Magus is born of at least one Warp-touched psyker parent. As the Fourth Generation of the cycle is born, the cult's Purestrain Genestealers sniff out psychically-gifted hosts. Soon enough, one of these hosts will give birth to a Magus. Though larger cults will have more than one of these psykers at their heart, most have but a single incumbent. Tall, clean of limb and with an imposing presence, the Magus can pass for a normal man and commands respect wherever he walks. In his soul, however, he is as much a creature of the void as a human. He holds the same otherworldly power in his eyes as the Patriarch he calls lord and saviour, and is bound by the same unearthly genetic drive to spread the cult far and wide. It is the Magus that speaks for his hidden brotherhood in matters both mystical and spiritual, and in many ways he is the mastermind behind the spread of the cult across its host planet and beyond.

Genestealer Familiars

The familiars that scamper and skitter around the feet of the Cult's leaders are not creatures of biological origin at all, but psychic manifestations of their masters' wills. Grotesque amalgams of human and Genestealer, they are alien cunning given physical form, subconsciously created in realspace from the psychic overspill of the cult's gestalt Broodmind.

Should a Patriarch or Magus dominate a region completely, the psychic shadow that gathers around him will grow darker and thicker until it begins to coalesce. This ever-shrinking miasma hardens into a many-limbed form. When the familiar is fully manifested, it skitters from its hiding place and runs to the heel of the xenoform that unconsciously created it. From that point on, it is as much a part of him as any hand or claw. Small and nimble, such a familiar is an excellent spy, able to scuttle through the tightest crawlspaces and report back to the cult's leader through the potent psychic bond that links them. Should its master be threatened by a physical attack, the familiar will leap up to claw at the attacker's eyes and throat, gouging its small but iron-hard talons into vulnerable flesh so the familiar's creator can deliver the coup de grace.

The Primus

Genestealer Cult

The Primus, war-leader of the Genestealer Cult during an unprising

Commanding the broodkin in stentorian tones, the Primus stalks through the fires of war with the surety of an alpha predator. He is the cult's ambush leader and front-line general, sowing destruction through the most prized targets of the enemy force. It is the duty of the Primus to show the supremacy of his kind's beliefs, rewriting the history of world after world in the blood of those naive enough to oppose him.

The Primus is a bombastic commander in times of war, but whilst the cult still remains in hiding, it is his duty to spread the Genestealer Curse to other planets. His innate gift for leadership and coordination sees him militarise the cult in short order, masterminding the takeover of flotillas of vehicles and even voidcraft. A strong champion and lauded hero amongst the broodkin, the Primus emerges only when the cult reaches a position of strength. Such individuals appear in an early generation, but typically not until the third or subsequent cycles. The foremost xenoscriveners of the Deathwatch theorise there is a hidden imperative that results in the manifestation of a Primus. This is either triggered when the cult’s numbers reach critical mass, their numbers and influence sufficient to take over a prey world, or when a Hive Fleet looms on the edge of that planet's star system.

The Primus' particular quirk of the Genestealer life cycle occurs independently, enhancing the development of an especially robust hostform to produce a largely humanoid warrior of prodigious strength and tactical acumen. Standing proud and straight, where his kin are hunched and gangling, the Primus cuts a dynamic figure. Where a Magus boasts a pin-sharp mental acuity and telepathic powers the equal of a Space Marine Librarian, the Primus has a supernatural dexterity and surety of focus that can see him bring down adversaries twice his size. 

The wargear of the Primus complements his approaches of stealth and guile, allowing him to lay low those in his path without raising any unwanted attention. Each Primus girds himself with the finest equipment the cult can provide, distilling toxins from his own virulent bloodstream and delivering them via silent-firing Needle Pistols and paralytic toxin claws. Some wield strange, sentient swords thought to be grown from the bony secretions of the Patriarch's bio-throne -- these blades are not only symbols of the Cult-father's trust, but deadly weapons in their own right, capable of stealing the life energy from those they strike to leave only withered husks behind.

As the cult's ascent reaches its peak, the Patriarch's behaviour changes as its instincts shift from survival and reproduction to the aggressive tendencies of a warrior bioform. These changes are reflected in the Primus, and when he deems the time right to lead the cult to war, he inherits command from Magus and Patriarch alike. As his plans unfold, a bow wave of terror, fire and anarchy spreads across the prey world. Should the cult survive the ensuing battles in strength, it will be the Primus that leads it to fresh prey, where the Purestrain Genestealers will begin the cycle of infection and insurrection anew.

Acolyte Hybrids

Acolyte Hybrids

A group of Genestealer Acolyte Hybrids charge against Imperial forces

Repulsive, cruel and possessed of an animal cunning, the Acolyte Hybrids are the foremost disciples of the Genestealer Cult. They are the offspring of the very first hosts to become infected. Though the parents of the Acolyte Hybrids are outwardly whole and sound, part of their mind has been taken over by the Genestealer Curse. Their love for their hideous offspring is even more intense than the usual bond between parents and children. The First Generation to be born unto them are twisted beyond recognition by the horrific germ-seed that has been carried to fruition within the implanted parent; these hybrids appear more like mutant Tyranids than altered humans. Those that reach maturity will flock together and interbreed, producing more generations in their turn.

Those Acolytes closest to the Patriarch in body and mind form his inner coven -- though savage and ferocious, they have a cold intelligence that makes them powerful agents of the cult. Having assimilated an echo of their parent's brain during gestation, they are able to use complex machinery and weaponry -- some even carry industrial tools to battle, wreaking devastation upon the flesh of those who stand before them. Almost all bear not two but three unnaturally powerful alien arms that mark them as the true inheritors of the Patriarch's curse. Their Genestealer ancestry makes them excellent shock troopers, able to tear apart the finest defenders of Humanity when they bring their claws to bear.

Acolyte Iconwards

The most intelligent and capable of the Acolyte Hybrids will be entrusted with a sacred duty -- the bearing of the cult's colours into battle. Though the cult's sigils and slogans spread ever further as it gains influence, they remain cryptic, their clandestine meanings known only to a few. Once the Primus and Magus muster their kin for the final uprising, however, the most favoured hybrids are presented with ornate standards lovingly fashioned by the prey-creatures that gave birth to them. In solemn ritual these banners are emblazoned with the cult's icon, not hidden away, but displayed proudly in bright colours.

These pseudo-religious artefacts have an electrifying effect upon the greater mass of the cult. It is a galvanising sight for one who has the taint of the Genestealer in his blood -- so much so that many an uprising's battles have been won simply because the Acolyte Iconward raised his standard. Not only do they form rallying points and statements of conquest, they also inspire those around them to greater feats of devotion and self-sacrifice, for they are the glory of the broodkin writ large, the underworld heraldry of Patriarch, Primus and Magus held high for all to see.

Hybrid Metamorphs

As the day of reckoning draws closer, some of those born to the First Generations of the cult’s unholy cycles begin to vary greatly in anatomy. Regardless of host species, they will exhibit freakish mutations, echoing not just the forms of the Genestealer, but those of the wider Tyranid race.

As the bio-fleets near the star system infected by the cult, the ominous Shadow of the Hive Mind falls upon the infestation's latest cycles. The weapon-limbs of First and Second Generation hybrids begin to change, displaying sickle-shaped talons the length of swords or pincers strong enough to crush rock. Whip-like ropes of sinew curl and thrash at the wrist, seeking victims to throttle and ensnare. Mouths are replaced with masses of thrashing tendrils, semi-psychic appendages that lick or burrow into their prey in order to siphon surface thoughts. Wattled throats sprout fat, globulous glands full of bio-acid that can burn through metal in seconds. These myriad mutations become more and more varied as the cult makes its final preparations for war. Their exceptional ugliness is surpassed only by their lethality -- the Hybrid Metamorphs are the most vicious of their kind, for they combine human intelligence with the raw alien power of Tyranid weapon-beasts.

To the broodkin, these bastard blends of human and Tyranid are blessed indeed. Their peculiar adaptations are seen as signs of greatness, stigmata bestowed upon them by the godly power of the Patriarch and the Great Beyond. Hybrid Metamorphs are worshipped as living saints by the infected hosts that sire them. The lairs of these hybrids are strewn with grisly offerings -- the Brood Brothers hope that by pleasing these genetic by-blows, they appease the otherworldly powers that have brought them into being. In truth, they are created not by the Patriarch's will, but by the immortal sentience of the Hive Mind -- for when a splinter fleet feels the presence of a powerful cult, it sends a psychic imperative that activates certain gene sequences and alters the phenotypical expressions of later hybrid generations to better prepare them for the war to come.

Though it is common for two of a Hybrid Metamorph's weapon-limbs to become solely adapted for war, the third remains truly prehensile, able to manipulate complex machinery and utilise the ingenious devices of Mankind. This lends a great deal of adaptability to these living weapons. For instance, on the day of conquest, a panicking platoon might seal itself in a rockcrete bastion or vault, thinking to wait for the danger to pass. Before long, however, they hear Hybrid Metamorphs tapping in the codes that send the doors swinging open, and are slaughtered in a flurry of wickedly barbed limbs. Small wonder that when the violence of the uprising finally erupts, these Hybrid Metamorphs fight as the champions of each Acolyte brood, taking on the choicest foes as they prove the supremacy of the cult over Humanity's herd.

Neophyte Hybrids

Neophyte Hybrids

Neophyte Hybrids of an unknown Genestealer Cult take up arms against Imperial rule

Neophyte Hybrids are Third and Fourth Generation cultists. They form the troopers, the line infantry and the greater mass of the cult's warriors. They are fiercely dedicated to the cult, and particularly the Patriarch at its heart, willing to devote their every moment to the furtherance of its dark aims. The mental and spiritual bond of the cult is so powerful that they are more than happy to hurl themselves into suicidal attacks or give their lives in exchange for their elders' survival. If the cult requires them to labour in mindless toil for long years so they can win the trust of a human organisation, they will do so without complaint. If their masters ask them to storm a position with nothing more than simple automatic weaponry and worker's fatigues, they will throw themselves into the teeth of the enemy guns without hesitation.

Hybrids of the Third Generation are still markedly alien in aspect. Though they have a classic bipedal anatomy, their distended craniums, beetling foreheads and waxy pallor mean they are often seen as mutants, and are hence shunned or even persecuted by the greater masses of the Imperium. Those of the Fourth Generation find it far easier to pass for human. Inveigling themselves into worker gangs, Administratum facilities, manufactorum shifts and hive networks, they slowly and carefully spread the cult's influence through the strata of Imperial society. Mining workers and militia fighters find it easy enough to secure low-grade weapons, either stealing them from those victims they silently take down or securing them on the black market. Over time, they amass a primitive arsenal of solid-shot weapons, blasting charges and pistols with which to wreak all manner of havoc when the time comes to reveal their true allegiance. When the Neophyte cultists attack, their sheer numbers make them a force to be reckoned with. 

It is common for a later cycle's Neophyte Hybrids to infiltrate a prey world's garrison force, or even those Astra Militarum regiments founded from amongst its populace. There, they work alongside the infected baseline Brood Brother humans that have felt the Genestealer's Kiss to ensure the cult's sympathisers spread ever further. The Neophytes propagate slowly throughout the ranks of the local military, taking over each corps from the inside until all of its soldiers pay obeisance to the Patriarch. These professional warriors carry Departmento Munitorum-issue Lasguns instead of Autoguns, and use Frag Grenades in place of repurposed mining explosives. Some even have access to heavier weaponry and may hijack the famously indomitable vehicles of the Astra Militarum to their cause.

The foot soldiers of the cult may well fight in the Imperium's wars, defending their homes from the predations of Chaos and from other xenos species. In doing so, they defend the cult and all that it has worked to achieve. Bound by the ties of the broodkin and a surety of common purpose, they make determined and capable warriors, but this only makes it all the more horrifying when their true nature is revealed. On the day of the great insurgency, when the populace looks to their military institutions to protect them, the citizens are appalled to find out that their saviours are not fighting against the monsters boiling up from the depths, but alongside them.

Purestrain Genestealers

Purestrain Genestealers

Purestrain Genestealers rise against an unknown Sept of the Tau Empire

Genestealers are the vanguard organisms of the Hive Fleets. The first Tyranids to be discovered by the Imperium, their true nature is obscured by a confusing multitude of legends. They are known as Snatcher-devils on some Imperial worlds, Cave Nightmares on others and Clawed Changelings on yet more. Every conceivable interpretation of the Genestealer Curse has been posited as truth across Mankind's domain, but even the most outlandish story does no justice to the awful truth behind these creatures and the cycles of damnation they propagate.

True Genestealers are characterised by their six limbs, bulbous craniums and ridged carapaces. They are bipedal and able to scuttle with horrible speed on their clawed lower limbs. Though they are agile in the extreme, their bodies are tough and durable; their torso is protected by a rock-hard exoskeleton that can turn aside a bullet. The upper sets of limbs are distinctly different, the foremost pair ending in razor-sharp claws, capable of slicing through even Tactical Dreadnought Armour. Their secondary limbs are typically shaped like gnarled hands, allowing the Genestealers to manipulate objects, climb and even operate simple technological devices such as touch-panels. Despite their dexterity, these secondary limbs are still more than capable of ripping a limb from its socket or tearing open light armour. The Genestealer's thickly muscled tail is largely vestigial, although it still aids in balance and agility. 

Isolated broods of this Tyranid creature are typified by a blue-indigo coloration. Such beasts have been encountered not only on numerous Space Hulks, notably the Sin of Damnation, but also upon the moons of Ymgarl, once thought home to a tentacle-mawed variation of the xenoform. Where a Genestealer is part of a larger Hive Fleet army, it will instead bear the same colouration as the rest of the Tyranids in its fleet. Such bioforms communicate via telepathy, enabling their broods to operate independently. Hive Fleet broods are often centred around an alpha predator sometimes mistaken for a Patriarch, though this beast is more accurately termed a Broodlord. This beast is not empowered by the psychic energies of a cult, but by a single brood of Genestealers. If divorced from the greater swarm of a Tyranid invasion, Hive Fleet Genestealers can evolve into a Purestrain form, their life cycle optimised to infect new hosts once new feeding grounds are viable.

By spreading their curse in secrecy, these creatures multiply the threat they pose in the manner of a virus. Even a single Purestrain Genestealer, borne across the stars by an unwitting pilot who lands upon a fertile planet, can spawn enough tainted progeny to take that world over from the bottom up. Such potential disasters are seeded across the Imperium in great measure. Only now, during the Time of Ending, are the defenders of Humanity becoming aware of the true scale of the threat.



A Dark Eldar Wrack stands in the way of a Genestealer Aberrant

Misshapen, lumpen and inhumanly strong, the Aberrants are the repugnant offshoots of the Genestealer life cycle. Though dim-witted, their instinctive need to defend their broodkin makes them valuable assets to the cult. In battle, they stomp and shuffle to the greatest concentrations of resistance. With heavy industrial tools raised, they moan slurred praise to the Patriarch as they charge in, causing impressive carnage with only their brute force and single-minded determination.

Not even the Magus himself knows what manner of strange processes gives rise to an Aberrant. Some quirk of ancestry ordains their fate as the gene-cycle is somehow perverted. Perhaps the initial implantation of the ovipositor was interrupted or spoiled, perhaps the interbreeding happened during a Warp tumult or sorcerous ritual, or perhaps the forbidden dabbling of curious bio-scryers gave rise to monsters that killed their creators upon birth. Whatever the circumstance that leads to their inception, these Aberrants soon seek out the lowest of the cult's dungeon-like lairs, shambling through the darkness until they find a Magus or Patriarch that will give them new purpose. From that point on, they are used as pure muscle for the cult's purposes. In times of war, they are sent as attack dogs to spread terror and confusion. Smashing open the defences of the upworlders, they commit grievous acts of destruction to impress their masters.

Armoured Vehicles



A group of Genestealer Neophyte Hybrids bring forth a Goliath truck against the servants of Nurgle

Goliath trucks are rugged transports originally designed to bear Imperial factotums through crypt complexes and mining tunnels. The vehicle's dense and robust construction makes it proof against the most hostile of underground environments, and its folded layers of chemically-treated permasteel give it a measure of protection against every industrial hazard the Imperium has yet encountered.

Even an unmodified Goliath truck can survive acid storms, hurricanes of forge-sparks, malfunctioning rad-chambers, and volatile toxin eruptions. Whatever damage they bear on the exterior, they keep those in their metal guts as safe as if they were locked in a command bunker. Whilst the cult lies quiescent, its Goliaths are used in everything from subterranean transit to stockpiling munitions. The duraglass screens inside each vision slit can be raised to make the vehicles airtight -- as useful for surviving the choking confines of a hazard mine as the poisonous atmosphere of battle. Their reputation is long-held; even the Astra Militarum has respect for the mighty Goliath.

Though an ascendant cult will make use of any type of vehicle, from lunar quads to civilian stretch-cars to mobile industrial macro-rigs, the Goliath truck is always the most sought after. These vehicles are customised with all manner of stowage, extra armour and sprayed-on cult symbols. They are acquired by means fair and foul by every cult that can find them, for they strike the perfect balance between unobtrusive civilian vehicle and pugnacious war machine.

No-one gives a second glance to a column of Goliath trucks bearing rag-draped miners through the streets, and workplace graffiti and personalisation is far from unusual in the lower classes of the Imperium, so even the cult symbols stencilled upon the vehicles' sides often go unchallenged. Then, when the mind-stimulus of the Magus or Patriarch signals the time is right, the broods within these vehicles throw open their hatches and burst out -- some still mistaken for human even in their warpaint and others so alien that even to witness them is to feel the cold claw of defeat clutching at the heart.

Built to the blueprint of a ubiquitous Standard Template Construct, the Goliath truck has been modified and adapted countless times across the industrial worlds of the Imperium. Most common of these variants is the Rockgrinder. Though compact, the Goliath Rockgrinder is built to withstand rockfalls, dam bursts and the fiery backwash of its clearance incinerator. Those huddled within have a great deal of protection from all but the highest-calibre weapons.


Genestealer Sentinel

A Sentinel piloted by a Genestealer Cultist

The Sentinel is a single-pilot robotic combat walker that can traverse landscapes where a wheeled vehicle would swiftly founder. Though designed primarily as a reconnaissance asset to stalk the killing fields of the Imperium, Sentinels are so versatile that they are in widespread use even behind the lines. They are a common sight in the industrial zones of the Imperium; hydraulic "bulk lifter" variants of this bipedal vehicle can be found shifting ammunition crates and ordnance cylinders in the shadowy dockyards and cache-districts where Genestealer Cults thrive. Such machines are easily retrofitted for warfare by the cultists that press them into service. Still more are simply co-opted from the military forces the cult has taken over from the inside. Regardless of source, on the day of battle, these walkers will be grouped together into two main roles -- either used as lightweight Scout Sentinels for forward operations or as heavier Armoured Sentinels that lend heavy firepower to the main body of the uprising.

In terms of sheer piloting skill, the Genestealer Cults may well boast the finest Sentinel operatives in the galaxy. Those walkers that were once industrial machines have been operated day and night by their assigned drivers -- Neophyte Hybrids who have become so expert in their use they can pick through a ruined metropolis with the ease a man might walk across a deserted parade ground.

Such pilots make excellent independent assets when the time to strike is nigh. The Scout Sentinels they operate boast a powerful weapon system that can be fired on the move; they are fast enough to move into position for a kill shot, yet small enough to operate undetected by a larger force. This makes them ideal for covert operations. Often, a crack team of Neophyte Hybrids will send their Scout Sentinels loping around the flanks of the enemy army. At a psychic impulse from the cult's overlords, they will open hostilities with a punishing volley that can rip out the exposed throat of the opposing force even before the battle has started.

Where Scout Sentinels have only a canopy of reinforced bars to protect the pilot, Armoured Sentinels have thick plated hulls, for they are built to operate even in the most dangerous war zones. Such enclosed walkers have the added bonus that no one can see the true nature of their pilot until it is too late, an advantage that is not lost on the cult's overseers. Those cults unable to sequester heavy war assets often use Armoured Sentinels as tank substitutes, fitting them with Lascannons, Missile Launchers, and perhaps even rare and temperamental Plasma Cannons. With such firepower at their disposal, the cult can theoretically take down even the heavy infantry and main battle tanks of an Adeptus Astartes strike force.

Leman Russ Battle Tank

Genestealer Leman Russ Battle Tank

Genestealer Cultists follow one of their own Leman Russ battle tanks during a battle

The heavy firepower of the Leman Russ Battle Tank is legendary, and also much sought after by those cults that expect to engage the foe at range. Built to last through standard decades, if not centuries, of harsh conditions and poor maintenance, this Imperial main battle tank is a natural choice for those cults that intend to bide their time before launching a single devastating strike. Those cults determined or lucky enough to secure entire squadrons of Leman Russ tanks are a terrifying prospect, as deadly at range as at close quarters. These concentrations of force bombard the enemy from afar to crack open even the safest of havens, allowing the xenospawn at the heart of the cult to get at their soft-bodied prey in the process.

The Leman Russ is constructed more as a rolling bunker than as fast-moving support. Its primary weapon is the Battle Cannon, an unsubtle sledgehammer of a gun that sends high-explosive shells hurtling into the midst of the enemy. Even the tanks of the foe can be crippled or destroyed by a direct hit from such ordnance. Sponsons are often fitted onto the Leman Russ' flanks, each bearing either a Heavy Bolter to scythe down enemy troops, or a Lascannon to crack open armoured targets. With the foe reeling, the cult will often follow up the volleys of its Leman Russ squadrons with a devastating assault from the clawing, screaming masses of its throng.

Cult Icons

The symbols of each Genestealer Cult are uncannily similar, whether borne on an Iconward's standard or hidden away as a brand of allegiance on a Brood Brother's chest. Many adaptations and interpretations have been adopted by cults across the Imperium, yet they all portray a similar, stylised bioform. Each cult uses its own variants of the insignia as it solidifies its own identity, but will also display the core symbol of the cult -- a long-bodied creature with ridges upon its spine that echoes the form of the Tyranids themselves often called a "wyrm."

The fact that each cult's icons are so similar, regardless of where they are encountered, is unsettling in itself. Perhaps those that create them are guided by strange dreams and visions brought about by the Hive Mind's Shadow in the Warp, where alien anatomies whirl and bulge in sanity-stealing profusion. Perhaps the form of the Tyranid is encoded within the gene-curse, rising to the front of the cult's collective mind unbidden. Either way, from the western reaches of the Segmentum Pacificus to the depths of the Eastern Fringe of the galaxy, those worlds that harbour Genestealer broodkin are emblazoned in a hundred different ways by eerily similar markings, brands of ownership that hint at the biological apocalypse to come.

Notable Genestealer Cults

If the High Lords of Terra truly comprehended the number of Genestealer Cults abroad in their realm, they would feel the chill of fresh terror creep across their souls. Though only six cults have been codified by the Ordo Xenos, data-harvests taken from Ghosar Quintus imply the presence of hundreds, perhaps thousands, in the Ultima Segmentum alone.


Sigil of the Blade Cog

  • Bladed Cog - The slave revolt of the planet Feinminster Gamma eventually proved more powerful than the Cult Mechanicus crusade that surged across its surface. The army of Magos Dominus Ovid Thrensiom had arrived in force seeking a rich harvest of bio-electricty from the planet's living population. The atmosphere of oppression and paranoia that resulted was fertile ground for the spread of an underground religion. When a Purestrain Genestealer was unwittingly borne to the planet's surface by the freighter Redspark, a widespread cult was soon to follow. The xenoform was seen as proof that there were other worlds beyond the clouds and that salvation could be found in its worship. When Thrensiom was overthrown, the broodkin of the Bladed Cog swapped one set of cruel masters for another, though the latter brotherhood are infinitely worse. Infesting the forge-clades of Feinminster Gamma now is the cult of the Bladed Cog. The code-brands and Electoos with which the planet's Tech-priest overseers mark their citizen workers are often altered in illicit inker-dens. The Omnissiah's Cog Mechanicum is changed and adapted to better resemble the jag-spined emblem with which the creed marks out its faithful. Slogan-tattoos are also common, worn across the collarbones or spine.

Sigil of the Hive Cult

  • Hivecult - The Hivecult is a prime example of a Genestealer infection that has spread like wildfire across a densely populated Imperial world. The planet of New Gidlam has thirteen hive cities upon its pollution-blasted surface, each harbouring tens of billions of souls. All bar one is besieged from below by the same cult. Though the cult's emergence began in each hive with a spate of ritual killings, the violence soon blossomed into all-out war. The icon of the bladed wyrm-form is carried by all the dynasty's members, whether they be the Brood Brothers of New Gidlam's Astra Militarum regiments, or the hiver gangs themselves. So militarised is the cult that the icons themselves are weaponised, appearing in stylised form as knuckle dusters, throwing stars or daggers. They are often used to slay those who stand in the cult's way, an act rich in symbolism originally started by the cult's Magus. Perhaps unwittingly inspired by the coming of Hive Fleet Leviathan, the brotherhood of the Hivecult wear regalia of bone-white and purple. There are those in the Imperium aware of the cult's infection of New Gidlam and their infiltration of the Astra Militarum defenders. However, each hive city's populace numbers in the billions, and the cult is well versed in the arts of secrecy, revealing its true numbers only when sure of victory.

Sigil of the Innerwyrm Cult

  • Innerwyrm - The Innerwyrm Cult infests the abattoir world of Fleishgate. A lynchpin planet that provides the meat of Grox, grontock and bovian to the Mawdlin System, Fleishgate has long been taken over by a Genestealer Cult. They take their inspiration from the arm-length intestinal parasites they find within the guts of their livestock, just as their hidden cult grows strong within the fat-bodied mass of Humanity's ignorant herd. The use of the saw-spined wyrm-symbol, inspired in part by the meatslasher machines the Innerwyrm cultists use in their daily slaughter, is not confined to Fleishgate. Many cults have elements that use ripping circular saws, whether to grind rock, cut through steelwood roots or salvage the parts of industrial machines -- it is common for such broods to echo this sigil upon their own standards.

Sigil of the Pauper Princes

  • Pauper Princes - The Pauper Princes have all but taken over the slum world of Chancer's Vale. Most of the populace lives in the squalid shanty towns that pepper the coasts, their skin badly desiccated by the constant salt-mining of minerals from its barren seas. Such is the deprivation and abject poverty of this Imperial world that many of its people turned to worship of the cult -- not because they were forced to by coercion or the Genestealer's Kiss, but because they are desperate for a way off-planet. The promises of Magus Marovitch Tenndarc saw swathes of the world's populace united in their devotions to the Star Saviour. Every Emperor's Day the Magus sermonised to rapturous crowds about the glories to come. Magus Tenndarc died saving the Star Saviour himself -- the cult's Patriarch -- by diving in front of a Ratling sniper's bullet. The Abhuman assassin was torn to pieces within the solar hour, Tenndarc attained the status of saint, and the cult's flock quadrupled in size.

Sigil of the Rusted Claw Cult

  • Rusted Claw - The worldwide minecorps that toil beneath the Mining World of Newseam unearth hundreds of tons of precious metal from the planet's crust each day. The sickeningly rich upworlders forbid the downtrodden miners from keeping the metal they dig out from the seams, let alone spending it, but much is smuggled away nonetheless. Known as the Cult of the Rusted Claw, this embittered brotherhood believes that the all-consuming emptiness of the void devours all, even metal. They see the tarnish of every coin and the rust that eats away at every vehicle as divine entropy brought to their world by their Patriarch, and they welcome its spread. Only when the oppression of the upworlders is gnawed away completely will they be truly free. The hybrids of the cult believe that an eternally hungry beast called the metallophagic wyrm will devour not only the flesh of the unbeliever, but also his creations. Their symbol shows the cog of industry being consumed by the wyrm-form that represents the Patriarch's great hunger.

Sigil of the Twisted Helix

  • Twisted Helix - Hailing from the macro-alchemical distilleries that provide the medicae-class Civilised World of Vejovium III with its exported medicines, the cult of the Twisted Helix has spread far and wide. The cult's broodkin skulk in enormous medifactoria that appear from the aristocracy's spires like the laboratory of some godly sage, all spiral glass pipelines and chimneys that belch strangely-coloured smoke. At a high cost in volunteers' lives, the magisters of the industrial cult have learned how to extract the germ-seed of the Genestealer and incorporate it into the curative syringe-phials that form a major part of Vejovium's medical exports. Though the imperfections of this bio-alchemical breakthrough have resulted in a great many aberrations and metamorphs, the process has seen the Twisted Helix swiftly spread its curse across the Vejovium System...and far beyond.

Sigil of the Cult of the Four-Armed Emperor

  • Cult of the Four-Armed Emperor - The Cult of the Four-Armed Emperor was originally incepted by the Trysst Dynasty of Ghosar Quintus. It spread its dire influence far and wide before coming under attack from the Deathwatch of the Adeptus Astartes. A dozen new infections have since grown in its image -- the Genestealers the original Tryssts sent to other planets under the guise of industrial shipments have sired new generations and variant cults in their turn.

Sacred Relics of the Cult

The strange artefacts held sacred by the Genestealer Cults all have some measure of alien power imbued in them by the gestalt Broodmind of their bearers. Only one of each of the following relics is usually found among a single cult.

  • Icon of the Cult Ascendant - The strange artefacts held sacred by the Genestealer Cults all have some measure of alien psychic power imbued in them by the gestalt Broodmind of their bearers. The sight of this icon can drive all members of the cult into a furious charge against the unbelievers.
  • Dagger of Swift Sacrifice - Those who work to hinder or reveal the cult are killed in long and painful ritual sacrifices to better appease the Patriarch, often using a weaponised form of the cult's symbol. The Dagger of Swift Sacrifice was devised not for a protracted kill, however, but a near-instantaneous one, the toxin-crystals upon its blade potent enough to kill even the xenos known as a Clawed Fiend with a single scratch.
  • Scourge of Distant Stars - The Brotherhood of Distant Stars whispers of the Scourge -- a voidcold sentience that moves from weapon to weapon, aiding the wielder as he lays low the fool and the unbeliever. Whether it inhabits the blade of an Acolyte Iconward or the bonesword of a Primus is of little import -- whosoever threatens the wielder will find their life sapping from a mortal wound as soon as they raise their blade.
  • Staff of the Subterran Master - Capped by a sculpture of a Tyranid god-form, the Staff of the Subterran Master resonates with animalistic power. Its strange psychic allure gives the wielder the ability to cause the very vermin of the land to rise up -- poisonous worms, biting spiders, milliasaurs and plague rats boil from cracks in the ground to assail the enemy even as the cult streams through the streets.
  • Sword of the Void's Eye - The sentience within the Sword of the Void's Eye is far more intelligent than its wielder, for within it lies a portion of the Hive Mind. The bio-fleet descending upon the host planet uses the eyes of the sword to spy on the populace and sample the thoughts of those whose blood it tastes. When laid at rest it will slither out a thin tongue that curls and twists in the dust, analysing the dead skin cells of the populace and gleaning vital bio-secrets for the invasion to come.
  • The Crouchling - The most favoured of cults by the Hive Mind are visited by the Crouchling, a skittering familiar that talks in a high, reedy voice. Though small and weak of limb, the Crouchling is a powerful psychic presence, able to cast hypnotic spells and visit mind-wracking hallucinations upon those who earn its master's ire.


  • Codex: Adeptus Custodes (8th Edition), "The Tale of the Ten Thousand", pg. 33
  • Codex: Genestealer Cults (7th Edition), pp. 7-9, 11-16, 18-48, 101
  • Codex: Genestealer Cults (3rd Edition Supplement) by Tim Huckelbery, pp. 1-16
  • Codex: Tyranids (6th Edition), pp. 99-100
  • Codex: Tyranids (5th Edition), pg. 40
  • Codex: Tyranids (4th Edition), pg. 39
  • Codex: Tyranids (2nd Edition), pp. 27-29
  • Freebooterz: Space Ork Army List
  • Space Hulk: Missions Book (3rd Edition), pp. 2-33, 42-45
  • Space Hulk: Missions Book (2nd Edition), pp. 7-20
  • Warhammer 40,000 Compilation (2nd Edition), pp. 88-115
  • Warhammer 40,000: Rogue Trader (1st Edition), pg. 211
  • Warhammer 40,000: Rulebook (8th Edition), pp. 140-141
  • White Dwarf 114 (UK), "Genestealers," by Paul Murphy, pp. 31-36
  • Deathwing (Anthology) edited by Neil Jones and David Pringle (2001 Edition), "The Alien Beast Within" by Ian Watson
  • Space Hulk (Novella) by Gav Thorpe
  • Deathwatch: Overkill (Board Game)
  • Space Hulk (2013 Video Game)
  • Space Hulk (1993 Video Game)