Grey Knights army rules, detachment abilities, stratagems and lore for Warhammer 40k, with links to the full unit datasheet table.
The Grey Knights are a secret and mysterious Chapter of Space Marines specifically tasked with combating the dangerous Daemonic entities of the Warp and all those mortals who wield the corrupt power of the Chaos Gods. They were created by the Emperor with the aid of Malcador the Sigillite at the time of the Horus Heresy to serve as Humanity's greatest weapon against the threat posed by the existence of Chaos. They have the honour of being implanted with gene-seed engineered directly from the genome of the Emperor Himself.
The Grey Knights act as the military arm or "Chamber Militant" of the Ordo Malleus, the Daemonhunters who form the oldest branch of the virtually omnipotent Inquisition. The Grey Knights' fortress-monastery, the Citadel of Titan, is based on Titan, the largest of the moons of the gas giant Saturn in the Sol System. It is kept as a private preserve of the Inquisition.
The existence of the highly secretive Chapter is virtually unknown outside of the Inquisition and the highest echelons of the Imperial adepta, and is a well-guarded secret enforced by mind-wipes and even assassination of Imperial citizens if necessary.
Unlike other Astartes, every Grey Knight is a potent psyker. Yet, in the 10,000 standard years of Imperial history, no Grey Knight has ever been corrupted by the Ruinous Powers of Chaos. Additionally, the Grey Knights do not follow the tenets of the Codex Astartes in the matter of force organisation.
Due to the unique manner in which the Grey Knights are recruited and trained, each warrior progresses through a series of pre-ordained ranks and will operate in a particular squad led by an individual of higher rank, rather than being assigned to a particular Battle Company. These squads may be called upon to act independently from the main body of the Grey Knight force, and have to operate at full efficiency even when light years away from the rest of their Chapter.
As such, the brother-captain who is the leader of each Grey Knight brotherhood, or any other Grey Knight unit commander, is obeyed immediately and without question by those under his command.
A light against the darkness, the Grey Knights stand against the greatest threat Mankind has ever faced. They are the champions of reason, order and righteousness, holding back Daemons and the scions of the Dark Gods.
They are the Imperium's mightiest weapon against the Warp, transhuman Space Marine psykers, and its single enduring hope for salvation. There is no greater threat to the galaxy than the denizens of the Warp and the Ruinous Powers that rule them.
Daemons and gods, these otherworldly horrors tear at the veil between the Realm of Chaos and reality, hungry for the souls of Humanity and the ruin of worlds. If left unchecked and unopposed, Daemons would claim the universe for their own, pulling down the pillars of creation and fashioning a never-ending nightmare where once the galaxy had been.
Daemons are unlike any other foe the Imperium faces, and against their unnatural horror men and women can find themselves powerless. The Emperor's armies are vast and numerous, from the void-borne fleets of the Imperial Navy and the endless ranks of the Astra Militarum to the superhuman Space Marines and the unimaginably powerful Titan Legions. Mortal foes cannot stand against the Imperium when it is roused to war, but the Daemon is not mortal.
History has proven that all people can be corrupted and even the mighty Chapters of the Adeptus Astartes are not immune to the unholy temptations of the Dark Gods. In His infinite wisdom the Emperor foresaw that even should He prevail against Horus, the threat of Chaos would remain to forever after threaten Humanity.
He knew that of all the Imperium's many foes, the daemonic was the greatest threat, and so He created a brotherhood of incorruptible warriors to fight Daemons. These were the Grey Knights, and they would stand as the Emperor's ultimate weapon against the gods of Chaos.
The Grey Knights are the most mysterious of all the Imperium's warriors. Their creation was the culmination of a plan conceived in the dying days of the Horus Heresy, hidden from even the Emperor's armies lest it be uncovered by His foes. Even now few in the Imperium of the 41st Millennium know of their existence, and those that do possess only fragments of the truth. Legends and myths surround the Grey Knights, and those tales told about them are filled with broad misconceptions and fanciful lies.
The vast hordes of Humanity know nothing of the Grey Knights, and the handful of Imperial citizens that have heard the name uttered assume them to be an arm of the much-feared Inquisition or a Chapter of the mythical, transhuman Space Marines. Some of the stories and fables taught by the Adeptus Ministorum hold the barest hints of the existence of the Grey Knights, but they are portrayed as silver-armoured angels, ghostly manifestations of the God-Emperor or shimmering reflections of the saints themselves as often as not.
Those Imperial soldiers that have fought alongside the Grey Knights and retained both their lives and their minds recall them only as Astartes of an unknown Space Marine Chapter, their unique weapons and psychic powers attributed to forgotten technology and tactical doctrine. Other Space Marines know better should they see a Grey Knight in battle, but are wise enough not to dwell long in thought about these mysterious warriors.
The Grey Knights is unlike any other Space Marine Chapter, built around the tenets laid down by Malcador the Sigillite and the first Grand Masters of the Chapter, "the Titans."
Though officially recorded as a Second Founding Chapter, the Grey Knights do not follow the dictates of the Codex Astartes: the great work of Roboute Guilliman whose edicts underpinned the creation of those other brotherhoods of the Adeptus Astartes. Instead, the secretive Grey Knights follow the tenets of structure they believe were handed down by the Sigillite, tenets born of the unique demands of their war against the Dark Gods.
While the Grey Knights are technically Astartes, they do not involve themselves with the ordinary activities of the other Space Marines. They have no primarch to revere, as their gene-seed was crafted from the genome of the Emperor Himself. They are attached to the Ordo Malleus -- serving as its Chamber Militant -- charged with uncovering and expunging the heretical taint of Chaos wherever it is found.
The Grey Knights Chapter is organised into large units called "brotherhoods," each one comparable in size to a Space Marine Battle Company. "Brother-captains" lead these formations, under the auspices of the Grand Masters, who in turn are guided by the decisions of the Supreme Grand Master.
The following Chapter hierarchy represents the order of battle of the Grey Knights Chapter as it stood in ca. 999.M41 before the birth of the Great Rift:
The Grey Knights are governed and directed by the Chapter Council, made up of the Chapter Lord, also known as the Supreme Grand Master, and the eight Grand Masters of the brotherhoods who all meet at an oaken table.
The structure of this council is one of the Grey Knights' oldest traditions, as laid down at the Chapter's Founding by Malcador the Sigillite and his eight Astartes recruits who had once been his Knights-Errant during the Horus Heresy.
The council meet in person rarely, for its members often fight far from Titan. Each member of the council has an equal voice, though the Chapter Lord has the responsibility to pass final judgement when there is no clear consensus among the Grand Masters.
Although the Chapter Lord's rule is ultimately absolute, he can only be appointed to his position by the unanimous consent of the Grand Masters, so it is nigh-impossible for a reckless or unsuitable candidate to achieve dominion over the Chapter.
Each Grand Master also holds sway over one of the Chapter's constituent bodies, such as its Chapter fleet, Armoury or Librarius. Each institution is nominally held to form part of that Grand Master's brotherhood, though he despatches elements of these organisations to undertake extended duties with others. This authority, only partly ceremonial, is tied to the command of a particular brotherhood, and over time the association has informed that brotherhood's fighting style and tactics.
Yet in truth a Grand Master's chief responsibility is on the battlefield. The Grey Knights are spread thin throughout the galaxy, and it is not always possible for a brother-captain of one of the brotherhoods to command every strike force. Thus the Grand Masters take charge of the most crucial campaigns where even an experienced brother-captain is not thought equal to the task. This most commonly happens when one of the Conclave Diabolus -- the one hundred and one Greater Daemons in which the Grey Knights take special interest -- is sighted in the mortal realm.
Most engagements of the Chapter will involve a single squad of Grey Knights supporting an Ordo Malleus Inquisitor, or a local force of planetary law enforcement, military forces or Astra Militarum.
For the most serious daemonic incursions, several squads of Grey Knights numbering usually about 20 Astartes are collected around the presence of a senior captain, or even a Grand Master.
In these circumstances, Tactical Squads will attempt to establish a beachhead in the Chaos-tainted area, before the Terminators and senior Astartes teleport down to the surface and engage the primary Daemon, banishing it back to the Immaterium.
The very presence of Grey Knights upon the field of battle is painful to Daemons and other Warp entities. The Grey Knights' gestalt psychic purity and powers are combined through a squad's Justicar into the Aegis, a psychic "choir" that is amplified by the presence of additional squads psychically "singing" in tandem.
These normally inaudible sonorous chants of detestation act as a weapon that repels the daemonic and makes it hard for these entities to maintain a presence in the physical universe. The presence of Telekines in Grey Knights squads enhances the potency of the Aegis: by raising psychic shields, the Telekines allow their battle-brothers to advance on targets with relative impunity.
This means that Grey Knights gain immense advantages against Chaos opposition, but the high expense to the Imperium of creating even a single Grey Knight leads to its own tactical problems -- for all their power, Grey Knights will always be badly outnumbered and must focus upon the fast and lethal application of force.
A byproduct of the use of the Aegis is the absence of any warcry for the Chapter. Grey Knights attack in seeming silence, and take care of their objective with remarkable economy of both action and communication.
A Grey Knights force also contains a high proportion of troops who can teleport through the Warp into battle, a high-risk maneuver which can turn the tide of combat if deployed well.
Teleportation may also require complicated battle-related arrangement and positioning and depending on the mission, can involve large number of squads teleporting in sync.
The Grey Knights are anathema to Daemons, their very presence raw and painful to the creatures of the Warp.
No other warriors of the Emperor are so adept at fighting Daemons, and each battle-brother is expertly trained in the many methods of banishing and destroying these deadly yet ephemeral foes.
There are many ways to banish a Daemon, almost as many as there are Daemons themselves. So it is that the Grey Knights possess a myriad means for vanquishing the denizens of the Warp, though not every method works on every Daemon, or even twice on the same creature.
The Chapter is therefore always adapting to combat the ever-changing face of their foe. It is a constant war of escalation that has been waged since the inception of the Chapter and before, when the Emperor first began unravelling the secrets of the Warp.
For every weapon and tactic the Grey Knights develop and employ, the Daemons counter with Warp-sorcery and trickery.
Chief amongst the Grey Knights' strategies concerning the vanquishing of a Daemon is obtaining knowledge of the beast's True Name. Knowledge of a Daemon's true name grants great power, which is why many Daemons adopt misleading pseudonyms or titles and seldom use their true names save in their most secretive of dealings.
For almost one hundred standard centuries Titan has been the secret fortress of the Grey Knights.
Glittering in the darkness of Saturn's shadow, the ice moon bristles with orbital defence platforms and fleets of sleek grey vessels.
Beneath its frozen surface generations of Grey Knights are created and laid to rest, in an endless cycle of birth and death.
At the base of Mount Anarch, tallest of Titan's peaks, rise the black basalt spires of the Citadel of Titan, the Grey Knights' fortress-monastery. Built by the Emperor over ten thousand standard years ago, the Citadel of Titan has endured through countless ages of war and strife.
Covered with dust and shadow, the dark edifice is festooned with Macrocannons and massive Lance turrets, their heavy barrels aimed out into the night. It is a forbidding sight that welcomes no visitors and brooks no trespass.
In fact, even the existence of the citadel is a closely guarded secret, and in the populous space lanes of the Sol System vessels give this satellite of Saturn a wide berth, their captains well aware that it does not pay to stray too close to the ominous moon.
Within the frigid halls of the citadel, servitors and Chapter serfs shuffle along empty corridors and tend to the millions of menial tasks required to keep the fortress running. Occasionally, a towering Grey Knight will stride past, always with purpose and always cloaked in the menacing air of barely contained power.
Lore excerpt from Warhammer 40k Wiki on Fandom, available under CC BY-SA 3.0.
25 Grey Knights datasheets on the current roster, each with its points, model statistics, keywords and abilities.
6 Grey Knights datasheets that are no longer part of the current army roster. They are kept for reference and for players whose collections still contain the models.