Genestealers Attack from the Warhammer 40k Wiki

The most formidable foes of the Imperium of Man are not those xenos who raise fist, claw, blade, or bolter and war with the sons of Terra. The most formidable foes are those which lurk in the dark; the creatures who seek not to kill, but to subvert. Alien minds and alien genetics, slowly replacing humanity with a twisted hybrid mockery of itself; the Genestealers!

Although Genestealers are related to Tyranids, they’re a special case; they’re not part of the Hive Mind; instead they have their own genetic and mental links with one another. Individual Genestealers are formidable foes, thanks to their six limbs and heavily armored carapaces. In groups their speed and ferocity make them even more deadly. Genestealers in their basic state use no technology or weapons, though they exhibit a frightening capability to understand such devices.

Genestealers have but one purpose in life—to infect. They exist only to spread their genetic material throughout the galaxies, subsuming all other life forms into their own twisted biology. Genestealers do not reproduce normally; they use their whip-like tongue/ovipositors to inject their own DNA down the throat of a subdued creature (of any gender). The infected victim awakens later, with no memory of the horrid incident. The new host may live normally for years before succumbing to the desire to mate and raise a family. The offspring of such a mating is inevitably a Genestealer Hybrid. Hybrids, in turn, birth purestrain members of the growing Brood.

Genestealer Brood

Ferocious, Armored Carapace, Fast

Skilled (+2) at: Close combat, Stealth
Bad (-2) at: Ranged combat, Long-term planning

STRESS (one per purestrain Genestealer; a Brood can be broken up into groups of 4 to 6 for convenience)

Genestealer Broodlord

Independent of the Hive Mind, Armored Carapace, Fast

Skilled (+2) at: Close combat, Directing Genestealer Broods
Bad (-2) at: Ranged combat

STRESS O

Genestealer cultists from the Warhammer 40k Wiki

Genestealers that infiltrate Imperial worlds mix their genetics with the local populace, creating Hybrids; stunted cross-breeds with three or four arms, thick hides, and swollen heads. In addition, the humans who are thus ‘related’ to Genestealers become psychically corrupt, forming Genestealer Cults.

Genestealer Hybrid

Extra Arm(s), Crafty, Psyker

Skilled (+2) at: Using human weapons, making mental attacks, using psychic powers
Bad (-2) at: Melee combat

STRESS O

Genestealer Cultists/Brood Brothers

Strength in Numbers, Civilian Vehicles, Stolen Weapons

Skilled (+2) at: Infiltration, Using human weapons, making human wave attacks
Bad (-2) at: Thinking for themselves

STRESS (one each; but cultists often deploy in groups of a dozen or so)

Every cult requires a high priest (or priestess); Genestealer cults are led by a Magus; a Hybrid of exceptional psychic power and great cunning. Because of their hybrid bloodline, a Magus of either gender must be careful to conceal their inhuman features as they present the public face of the cult.

Genestealer Magus

High Concept: Hybrid Mastermind
Trouble: Inhuman appearance
Other Aspects:

Extra arm(s)
Cult Leader
Psyker

APPROACHES:
Careful: +2
Clever: +3
Flashy: +1
Forceful: +0
Quick: +1
Sneaky: +2

STUNTS
Domination: Because I use psychic Domination, I gain +2 to Sneakily convince others to do my will.
Psychic Summons: Because I am a Magus and command my cult, once per game session I can summon additional Hybrids and Brood Brothers to my side by will alone.
Smite!: Because I psychically smite my foes, I gain +2 to make Flashy psychic attacks.

STRESS OOO          REFRESH: 3

Every Genestealer infestation is ruled by a Patriarch, the genetic progenitor of the entire brood. Over the years, Patriarchs grow larger and stronger than their offspring, becoming very dangerous threats.

Genestealer Patriarch with Magus from the Warhammer 40k Wiki

Genestealer Patriarch

High Concept: Eldest Genestealer
Trouble: Large size
Other Aspects:
Infect the world!
Commanding Presence
Claws

APPROACHES:
Careful: +1
Clever: +2
Flashy: +0
Forceful: +2
Quick: +1
Sneaky: +3

STUNTS
Armored Carapace: Because I have an Armored Carapace, I gain +2 to Forcefully defend against attacks.
Genestealer Mobility: Because I am a Genestealer and can run up walls and across ceilings, I gain +2 to Sneakily create advantages of positioning.
Menace: Because I exude an air of Menace, once per game session, when I reveal my presence I can cause people who see me to freeze in their tracks.

STRESS OOO          REFRESH: 3

Variations

Because Genestealers mix their genetics with every species they encounter, the galaxy is full of variations. Gamemasters should feel free to modify the stats above to model such variants. For example:

Adrenal Genestealers

Armored Carapace, Fast, Frenzied

Skilled (+2) at: Close combat, Outflanking and outmaneuvering
Bad (-2) at: Ranged combat, Stealth

STRESS (one per purestrain Genestealer; a Brood can be broken up into groups of 4 to 6 for convenience)

Genestealers used directly as shock-troops by Tyrannid hive fleets are often seen with lamprey-like adrenal gland biomorphs attached to their bodies. The direct injection of adrenaline into the Genestealer’s system gives them unsurpassed speed and striking power, and sends them into a battle frenzy that can only end in death.

Vectori-strain Genestealers

Fast, Silent, Patient

Skilled (+2) at: Close combat, Hiding, Ambushing
Bad (-2) at: Ranged combat

STRESS OO

Another alternate genetic line, encountered in the Jericho Reach, has been classified as the Vectori-strain. These Genestealers are smaller than other purestrains, and their carapaces are significantly thinner. They have developed the ability to move with absolute silence, even when running at full speed. Their optimized metabolisms allow them to wait motionless and silent for long periods of time without succumbing to hunger. They are masters of ambush tactics, and often hunt alone.

Ymgarl Genestealer Hybrid from the Warhammer 40k Wiki

Ymgarl Genestealer

Feral, Armored Carapace, Chameleon Skin

Skilled (+2) at: Close combat, Blood-drinking, Stealth
Bad (-2) at: Ranged combat

STRESS O

First encountered on the planet Ymgarl, this Genestealer variation have been separated from their progenitors for many generations, and have hybridized extensively with local lifeforms. As a result, Ymgarl Genestealers have chameleon-like skin, and the ability to alter their rubbery forms somewhat; claws can stretch into tentacles, carapaces can be made to thicken in response to enemy fire, and even their claw-like fingers can be morphed into handfuls of blades. The price of this adaptability is a raging blood-thirst; the Ymgarl metabolism cannot be sustained by the slow process of eating and digestion–only the direct ingestion of blood through the face-tentacles will do.