Warhammer 40k Psychic Powers — Lore & Rules Guide

Psychic powers in Warhammer 40,000 are among the most devastating, and most dangerous, abilities in the setting. From the lowliest sanctioned psyker to the Emperor of Mankind, those who draw on the Warp can reshape reality. But the Warp always demands a price.

This guide covers the lore behind psychic powers, how psykers are graded, how psychic attacks work on the tabletop in 11th Edition, the most psychic factions, and the forces built to hunt them.

What Are Psychic Powers in 40k?

Psychic powers are supernatural abilities fuelled by the Warp, the dimension of raw emotion and psychic energy that lies behind realspace. Individuals born able to tap into it are called psykers, and they appear among most of the galaxy’s species.

For humanity, psykers are both essential and feared. The Imperium depends on them: Astropaths carry messages across the stars, and the Emperor Himself, sitting upon the Golden Throne, is the most powerful human psyker who has ever lived. (Navigators, who steer ships through the Warp, carry a related but separate mutation; see the FAQ below.) Yet every psyker is also a potential doorway for daemons, so they are treated with suspicion and kept under strict control.

Psychic abilities take many forms: telepathy, telekinesis, pyrokinesis, divination, biomancy (manipulating living flesh) and stranger powers that defy classification. The Imperium only sanctions trained, controlled use of these gifts, while Chaos sorcerers embrace far more dangerous and forbidden paths.

What sets psychic power in 40k apart from magic in many fantasy settings is the risk. Every use of it means reaching into a dimension inhabited by malevolent entities. The Warp is not a neutral energy source. It is alive, hungry and hostile.

How Psychic Powers Work — Drawing from the Warp

The Warp, also called the Immaterium, the Empyrean or the Sea of Souls, is a parallel dimension made of psychic energy. The emotions of every sentient being feed into it, creating currents, storms and, ultimately, the Chaos Gods themselves.

When a psyker uses their power, they open a conduit between realspace and the Warp, draw energy through their mind, shape it with their will and release it into reality. That is dangerous for several reasons:

The Warp resists control. Warp energy is saturated with emotion and, in places, sentience. Shaping it takes immense concentration and willpower.
Daemons are always watching. A psyker using their gift shines like a beacon in the Warp, and daemons are drawn to it. The more powerful the psyker, the more dangerous the attention they attract.
Overreach is catastrophic. A psyker who channels more than they can control risks being consumed, burned out from within or turned into a gateway through which daemons can enter realspace.
The Warp is corrupting. Long exposure to Warp energy warps mind and body. Many psykers slowly go mad, develop mutations or become unwitting pawns of Chaos.

To reduce these risks, the Imperium gathers up its psykers and subjects them to brutal training and mental conditioning on Terra. Many don’t survive the process, but those who do can use their powers with a degree of safety.

Chaos sorcerers, by contrast, embrace the Warp’s dangers. They bargain with daemons and accept the Warp’s gifts, gaining great power at the cost of their humanity. The Thousand Sons are the most extreme example: a whole Legion of sorcerers, most of whose warriors were reduced to dust inside their armour by the Rubric of Ahriman.

Psyker Levels — The Assignment Scale

The Imperium grades psychic potential using a scale usually called the Assignment, which runs through the letters of the Greek alphabet. In most sources, only the top grades describe actual psykers. The middle of the scale covers ordinary humans with no meaningful psychic ability, and the bottom end describes people with a negative psychic presence: the psychic nulls known as Pariahs or Blanks.

How the scale breaks down

Alpha-Plus: The most powerful psykers, so dangerous that in most accounts the Imperium destroys them or keeps them under extreme restraint rather than letting them serve. The Emperor and the most powerful Primarchs are generally described as being beyond even this grade.

Alpha and Beta: Exceptionally powerful psykers. Individuals capable of overwhelming psychic feats sit here, and the most renowned Space Marine Librarians are usually described as operating at the upper end of the scale.

Gamma to Iota: The bulk of working psykers, from highly capable to weak. Sanctioned combat psykers, Astropaths and the many minor talents gathered by the Black Ships all fall somewhere in this range. Iota is generally treated as the lowest psyker grade.

Below Iota: Ordinary humans with no useful psychic ability. Most of the Imperium’s population falls here.

The far end of the scale (Omega and its neighbouring grades): Psychic nulls, called Pariahs, Blanks or Untouchables. They have no presence in the Warp at all, suppress psychic phenomena around them and are deeply unsettling to normal humans and agonising to psykers. The Sisters of Silence and Culexus Assassins are drawn from them.

Exact grade boundaries vary between sources, so treat the Assignment as a rough ladder rather than a precise measurement.

Perils of the Warp

The most feared consequence of psychic power is Perils of the Warp, the backlash that happens when a psyker loses control of the energies they are channelling. In the lore, Perils takes many horrifying forms:

Psychic backlash: the psyker’s mind and body are burned out, causing severe injury or death.
Daemonic possession: a daemon forces its way through the psyker’s weakened mental defences and takes control of their body.
Warp breach: reality tears open around the psyker, letting daemons pour into the material world.
Uncontrolled discharge: a blast of raw psychic energy that kills friend and foe alike.
Loss of the soul: the psyker’s soul is dragged into the Warp, leaving an empty husk behind.

The Chaos Gods, and Tzeentch above all, delight in snaring psykers, and many daemonic incursions in the Imperium’s history began with a single psyker losing control.

This is why the Imperium treats psykers with fearful necessity. The Black Ships sweep the galaxy, gathering emergent psykers and carrying them to Terra. There, in broad terms, they face one of three fates: sanctioning and training for Imperial service, soul-binding to the Emperor (the painful ritual that creates Astropaths), or sacrifice to sustain the Golden Throne.

How Psychic Powers Work on the Tabletop

Rules described here reflect Warhammer 40,000 11th Edition (launched June 2026). Faction rules, datasheets and points change with each codex and Munitorum Field Manual update, so always check the current rules for your army.

There is no separate Psychic phase in 11th Edition. It was removed in 10th Edition and has not come back. Psychic powers are part of the normal turn: most offensive powers are weapon profiles used in the Shooting or Fight phase, and support powers are abilities that work in the phase their datasheet says.

Psychic attacks and the Psyker keyword

Psychic weapons: Many psyker units have ranged or melee weapon profiles flagged as psychic. They are resolved like any other attack: roll to hit, roll to wound, your opponent saves. The psychic label matters because some units and abilities interact specifically with psychic attacks.

The Psyker keyword: Psyker units carry the PSYKER keyword, and some weapons have an Anti-Psyker ability that makes them more effective against those units. Under the 11th Edition Leader rules an attached unit has every keyword of every model in it, so attaching a Psyker character to a squad makes the whole unit a Psyker unit for those weapons. See Leader rules in 11th Edition.

Hazardous weapons: Some powerful psychic weapons are Hazardous, the tabletop echo of Perils of the Warp. After firing one you make a Hazard roll; in 11th Edition a roll of 1–2 fails and inflicts mortal wounds (one, or three if the unit is made up entirely of Monsters or Vehicles). Our 11th Edition cheat sheet has the full table.

Other 11th Edition changes also affect psykers: a unit can benefit from only one Stratagem per phase, and cover now worsens the attacker’s Ballistic Skill by 1 rather than improving saves. That applies to psychic shooting like any other ranged attack. For the full list, see the 11th Edition rules changes.

Psychic-heavy armies

Factions with strong psychic themes, such as Thousand Sons and Grey Knights, have army rules, detachments and Stratagems that expand what their psykers can do. The Thousand Sons army rule, for example, is built around their sorcerers performing powerful rituals. These rules come from each faction’s codex, which stays in use until that faction’s 11th Edition codex replaces it, so check the current book for exact details.

Best Psyker Factions

Some factions are defined by their psychic mastery. These are the standout psyker armies:

Thousand Sons

The Thousand Sons are the premier psychic faction in Warhammer 40,000. Led by the Daemon Primarch Magnus the Red, the Legion’s surviving warriors are sorcerers, and most of the rest are Rubric Marines: suits of armour animated by sorcery, with only dust inside where a warrior once stood.

On the tabletop, the Thousand Sons army is built around psychic output. It rewards you for taking sorcerer characters, and even their core Rubric Marines carry psychic firepower. If you want to play the psychic faction, this is it.

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Grey Knights

The Grey Knights are the Imperium’s elite daemon hunters, and every battle-brother is a trained psyker. Psychic ability is a requirement for joining the Chapter. They fight with force weapons that channel their psychic power into devastating strikes.

On the tabletop, Grey Knights combine elite melee with psychic attacks spread across almost every unit.

Aeldari (Craftworlds)

The Aeldari have immense psychic potential. Their Farseers are among the most skilled psykers in the galaxy, able to read the skeins of fate, and Warlocks and Spiritseers also wield the Warp in battle.

Aeldari use the Warp with far more discipline than humans, through the strict mental focus of the Paths and protective spirit stones. This is born of necessity: Slaanesh hungers above all for Aeldari souls.

Tyranids

The Tyranid Hive Mind is arguably the greatest psychic presence in the galaxy: a gestalt consciousness spread across countless organisms, whose psychic shadow, the Shadow in the Warp, disrupts communications and torments psykers.

Tyranid synapse creatures such as Hive Tyrants, Neurotyrants and Zoanthropes channel the Hive Mind’s power into psychic attacks. Zoanthropes in particular are little more than floating brains that hurl blasts of psychic energy capable of punching through heavy armour.

The Librarius — Space Marine Psykers

Within most Space Marine Chapters, psykers serve in the Librarius, which maintains psychic discipline, keeps the Chapter’s records and provides psychic support in battle.

Librarians combine the physical might of a Space Marine with potent psychic abilities. They advance through a hierarchy of ranks:

Lexicanium: the junior rank, for psykers still early in their training.
Codicier: fully trained Librarians.
Epistolary: senior Librarians of great power and experience.
Chief Librarian: head of the Chapter’s Librarius and one of its most senior officers.

Famous Librarians include Mephiston of the Blood Angels, who is said to have overcome the Black Rage by force of will and is counted among the Imperium’s mightiest psykers, Tigurius of the Ultramarines, known for his prophetic visions, and Ezekiel of the Dark Angels.

Not every Chapter has a Librarius. The Space Wolves call their psykers Rune Priests and insist their power comes from Fenris rather than the Warp, a distinction most Inquisitors find dubious. The Black Templars reject Librarians entirely, seeing psychic power as too close to the witchcraft they are sworn to destroy.

Anti-Psyker Forces

Where there are psykers, there are those who hunt them. Several forces in the galaxy exist specifically to counter psychic threats.

Sisters of Silence

The Sisters of Silence are an order of women who are all Blanks, psychic nulls. In their presence psychic powers falter, daemons weaken and psykers suffer pain and disorientation.

The Sisters fought alongside the Adeptus Custodes during the Horus Heresy. In the Era Indomitus they have returned to prominence, again fighting beside the Custodes as the Talons of the Emperor.

Culexus Assassins

The Culexus Temple of the Officio Assassinorum recruits only from exceptionally strong Pariahs. A Culexus Assassin’s null aura horrifies normal humans and can kill psykers outright, and their Animus Speculum turns that null-field into a weapon that is deadliest against psychic targets.

On the tabletop, the Culexus is a specialist: most valuable against psyker-heavy armies such as Thousand Sons or Grey Knights. Check its current datasheet for exactly how its anti-psyker abilities work.

Khorne — The Anti-Sorcery God

Among the Chaos Gods, Khorne is unique in his hatred of sorcery. The Blood God sees psychic power as a coward’s weapon compared to the honest brutality of axe and blade, and his followers shun sorcerers and psykers.

That makes for an awkward relationship within the forces of Chaos. Khorne’s followers may fight beside sorcerous warbands like the Thousand Sons against the Imperium, but they despise them, and such alliances rarely last.

Frequently Asked Questions

What is the most powerful psychic power in 40k lore?

The Emperor’s psychic abilities are in a class of their own. He powers the Astronomican (a galaxy-spanning psychic beacon), His will holds back the Warp breach beneath the Imperial Palace through the Golden Throne, and His power was central to creating the Primarchs. Among other feats, Magnus the Red’s psychic warning to the Emperor during the Horus Heresy is one of the most devastating in the lore: breaking through the Imperial Palace’s psychic wards shattered the Emperor’s secret Webway project and had catastrophic consequences.

Can any faction use psychic powers?

Most factions have at least some access to psykers. The main exceptions are the T’au (who have almost no presence in the Warp), Khorne-devoted forces (who reject sorcery) and the Leagues of Votann, among whom psykers are rare, though their Grimnyr are psykers. Necrons don’t use Warp-based powers at all, although some of their technology produces similar effects.

Is there a Psychic phase in 11th Edition?

No. The dedicated Psychic phase from 8th and 9th Edition was removed in 10th Edition and has not returned in 11th. Psychic attacks are weapon profiles used in the normal Shooting and Fight phases, and other psychic abilities work when their datasheet says. Powerful psychic weapons are often Hazardous, which keeps the risk of Perils of the Warp in the game.

Which army is best for a psyker-themed list?

Thousand Sons are the definitive psyker army: their army rule revolves around sorcery, and most of their units have psychic weapons or abilities. Grey Knights are the Imperium’s equivalent, with every model a psyker. Aeldari Craftworlds offer a subtler psychic army, with Farseers and Warlocks providing powerful support.

What happens when a psyker dies in the lore?

In many accounts, a psyker’s death can send a ripple through the Warp, and a powerful psyker dying violently can draw daemons or weaken the barrier between realspace and the Warp. That is one reason the Imperium handles psykers, living or dead, with such caution.

Can psykers be cured or have their powers removed?

Psychic ability is an innate mutation. The Imperium does not cure it; it trains, binds or uses the psyker instead. The soul-binding ritual that creates Astropaths doesn’t remove their powers but ties them to the Emperor, protecting them from daemonic corruption at a heavy cost. It burns out their eyes, which is why Astropaths are blind.

What is a force weapon?

A force weapon is a sword, staff, axe or similar weapon fitted with a psychic matrix that channels its wielder’s psychic energy. In a psyker’s hands it can strike with far more than physical force, and it is especially deadly to daemons and other Warp entities. Space Marine Librarians, Grey Knights and Imperial psykers carry them. Mephiston’s sword Vitarus is a famous example.

Are Navigators psykers?

Not in the usual sense. Navigators carry a distinct mutation, the Navis Nobilite gene, which gives them a third ‘warp eye’ that lets them see the Warp’s currents and the Astronomican’s light so they can steer ships safely. They are bred within their own Navigator Houses rather than collected by the Black Ships. Their gift is closely related to psychic power but is treated as separate from ordinary psykers.

Warhammer 40k Psychic Powers — Lore & Rules Guide