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"Fear not the psyker."

– A 10-foot tall psychic super soldier capable of shooting lightning bolts and fireballs with just the power of his mind.

"There are two great errors: First, to pretend that the Path of Heaven does not exist. Second, to follow it."

– Some dead guy from Chogoris.

Librarians are Space Marine psykers. Unlike Imperial sanctioned psykers, Librarians are less likely to be fucked inside out by daemons, due to a combination of the intense indoctrination regimes of the Space Marines, immense mental fortitude brought by their Librarian training, and the higher quality of their psychic hoods. They are armed with Force Weapons such as a Force Sword, Force Axe or a Force Staff. Often overheard punishing xenos and heretics alike while screaming cheesy one-liners like "Your book is overdue, BITCH!". They have varying degrees of awesomeness depending on what writer and/or chapter. Usually though, they dominate the battlefield and are feared by both friend and foe as they wield a vast selection of pure psykic awesomeness.


Back during the Great Crusade, when the Primarchs were reunited with their legions, the Space Marines began discovering some of their new recruits had psychic potential. Wanting to utilize this and prevent them from falling to Warp corruption, Magnus the Red, Sanguinius, and Jaghatai Khan proposed the creation of Librariums, divisions of the Legions which would take in psyker Space Marines and train them to use their powers for the good of the Imperium of Man. Seeing the possible good, the Emperor agreed, authorizing the go ahead. When the Librarium proved effective, they spread to other Legions. However, a number of Primarchs, namely Mortarion (he's got psyker issues that would make a Culexus blush), Rogal Dorn, Corax, and Leman Russ opposed the training of Librarians and wanted the program shut down, believing that the powers of the Warp could not be controlled (Russ maintained that Rune Priests were not actually Librarians, given that the Space Wolves insistently maintained that they drew power from Fenris, not the Warp except not really...). Further concern was raised with Magnus's constant peering into the Warp to learn more about his powers, which Russ and Mortarion felt warranted censure.

Then Nikaea Happened[edit]

See Council of Nikaea for the highlights.

Long story short, Big Emps banned Librarians, but not everyone listened

"Modern" 40k[edit]

There is obviously a bit of historical revisionism going on, because most accounts from the 41st Millenium look back at Nikaea and suggest that the Emperor actually said "yes" to Librarians, so long as they were trained in a controlled and careful manner. Which is what the White Scars and Blood Angels were doing at the time anyway, it was only the Thousand Sons who ruined it for everyone by thinking there should be no limits.

By M41 it has been left it up to individual Chapters whether or not to use Librarians, and most Chapters have Librarians to some degree or another, with the noticeable exceptions of the Black Templars and the Marines Malevolent; the former is for reasons that nobody can explain (some theories include a gene-seed quirk or a byproduct of the Cacodominus's destruction; the Black Templars just shrug and say that it's just the Emperor's will), and the latter is probably because they are the biggest dickheads in the galaxy and the Black Ships make sure they don't get any Psykers for Gene Seed implantations or the fact they could be loyalist Iron Warriors. And now with the creation of Primaris Marines comes their version of the Librarians. Also, seems like Morty compromised in the end.


Among Codex compliant Chapters, the ranks of the Librarium are based on their level of training and advancement. They are as follows:

  • Chief Librarian: The head of the Librarium, and the most powerful psyker in the Chapter. He is also one of the masters of the Chapter and usually a senior adviser to the Chapter Master. On the tabletop they are usually represented by named special characters of psychic mastery level 3 (or level 2 if they occasionally have some other unique ability). If you don't have a special character in your chosen chapter, then you'll just have to settle for a cool Epistolary.
  • Epistolary: The highest rank below Chief Librarian, Epistolaries serve as the main communication aides on the battlefield, sending psychic messages through the Warp to their brothers in the Librariums, similar to Astropaths, but without having their eyes burned out. While no longer explicitly stated in the 6th edition codex, Epistolaries have traditionally been psychic mastery 2 on the tabletop with the ability to know and cast two powers per turn.
  • Codicier: Mid-level Librarians, who evaluate reports from campaigns and document them in their Librariums. Supposedly represented on the tabletop as the common variety "Librarian", only at level 1.
  • Lexicanum: Entry-level Librarians, they are responsible for compiling battlefield reports for the Codiciers. Interestingly, they don't wear psychic hoods, or even helmets unless in dangerous environments. Haven't been represented on the tabletop since 2nd edition, when they were WS/BS4 W1 A1 Ld8 and a psychic power.
  • Acolytum: Librarians in training. Brought in from the battle companies before or shortly after they leave the Scout company, they're tested for psychic potential. It's possible that the Acolytum may be killed in the process, but that's life in a Space Marine Chapter for you. If they survive they're enrolled in Introduction to Mind Bullets and How Not to Melt Your Head 101.


Additional types of Librarian[edit]

Forces of the Codex Compliant Astartes
Command: Apothecary - Brother-Captain - Brother-Sergeant - Chaplain - Chapter Master
Command Squad - Honour Guard (Victrix Guard) - Librarian - Techmarine
Troops: Assault Squad - Centurion Squad - Chapter Serf - CATs - Devastator Squad
Scout Squad - Tactical Squad - Terminator Squad - Veteran Squad
Great Crusade-era: Breacher Siege Squad - Consul - Despoiler Squad - Destroyer Squad
Legion Herald - Legion Outrider Squad - Legion Vigilator - Moritat
Master of the Signal - Praetor - Reconnaissance Squad - Seeker Squad
Sky Hunter Squad - Tactical Support Squad
Structures: Castellum Stronghold
Transports: Land Raider - Mastodon Heavy Assault Transport
Razorback Transport - Rhino Transport - Spartan Assault Tank - Termite
Vehicles: Bike Squad - Dreadnought (Castraferrum - Contemptor - Deredeo
) - Javelin Attack Speeder - Jetbike - Kratos Heavy Assault Tank
Land Speeder - Predator Tank - Sabre Tank Hunter - Sicaran Battle Tank
Ordnance: Hunter - Legion Arquitor Bombard - Rapier Armoured Carrier - Stalker
Thunderfire Cannon - Whirlwind
Flyers: Caestus Assault Ram - Fire Raptor - Orgus Flyer - Storm Eagle - Stormbird
Stormhawk - Stormraven - Stormtalon - Thunderhawk - Xiphon Interceptor
Superheavy Tanks: Cerberus Heavy Tank Destroyer - Fellblade Super-Heavy Tank
Typhon Heavy Siege Tank
Spacecraft: Boarding Torpedo - Drop Pod - Space Marine Landing Craft
Allied Space Marines: Fallen Angel - Primaris Marine - Blood Angels - Dark Angels
Deathwatch - Grey Knights - Space Wolves - Black Templars
Forces of the Primaris Marines
Command: Helix Adept - Judiciar - Primaris Ancient - Primaris Apothecary
Primaris Captain - Primaris Chaplain - Primaris Librarian - Primaris Lieutenant
Primaris Techmarine - Vanguard Librarian - Vanguard Lieutenant
Troops: Aggressor - Bladeguard Veteran - Eliminator - Eradicator - Hellblaster
Inceptor - Incursor - Infiltrator - Intercessor - Reiver - Suppressor
Structures: Hammerfall Bunker
Vehicles: Gladiator Tank - Impulsor - Invictor Tactical Warsuit - Invader ATV
Primaris Outriders - Redemptor Dreadnought - Repulsor Tank - Storm Speeder
Super Heavies: Astraeus Super-Heavy Tank
Flyers: Overlord Gunship
Spacecraft: Space Marine Landing Craft
Allies: Space Marines
Forces of the Blood Angels
Command: Apothecary - Brother-Captain - Brother-Sergeant - Chaplain
Chapter Master - Librarian - Sanguinary Priest - Techmarine
Troops: Assault Squad - Devastator Squad - Sanguinary Guard - Scout Squad
Tactical Squad - Terminator Squad - Veteran Squad
Death Company: Death Company - Death Company Chaplain - Death Company Terminator
Great Crusade-era: Angel's Tears - Crimson Paladin - Dawnbreaker
Walkers: Contemptor-Furioso Dreadnought - Contemptor-Incaendius Dreadnought
Death Company Dreadnought - Dreadnought - Furioso Dreadnought
Librarian Dreadnought
Transports: Razorback - Rhino
Vehicles: Baal Predator - Land Raider (Land Raider Crusader - Land Raider Phobos
Land Raider Redeemer - Land Raider Angel Infernus
Predator Tank - Vindicator - Hunter - Stalker - Whirlwind
Flyers: Stormhawk - Stormraven - Stormtalon - Storm Eagle - Thunderhawk
Spacecraft: Boarding Torpedo - Drop Pod - Space Marine Landing Craft
Allies: Space Marines - Primaris Marines
Forces of the Dark Angels
Command: Apothecary - Company Master - Interrogator-Chaplain
Chaplain - Knights Cenobium - Librarian - Techmarine
Deathwing Knight - Dark Angels Grand Master
Deathwing Companion
Troops: Assault Squad - Deathwing - Company Veterans
Devastator Squad - Interemptors - Scout Squad
Tactical Squad - Ravenwing Black Knight
Watcher in the Dark
Structures: Fortress of Redemption
Walkers: Dreadnought (Deathwing Dreadnought - Contemptor Dreadnought)
Contemptor-Mortis Dreadnought - Mortis Dreadnought
Transports: Land Raider (Land Raider Phobos - Land Raider Crusader
Land Raider Redeemer - Land Raider Ares
Land Raider Solemnus Aggressor) - Rhino
Vehicles: Bike Squad - Razorback - Predator - Vindicator - Hunter
Stalker - Whirlwind - Land Speeder Vengeance
Ravenwing Darkshroud
Flyers: Dark Talon - Nephilim Jetfighter - Stormraven - Storm Eagle
Spacecraft: Boarding Torpedo - Drop Pod - Space Marine Landing Craft
Hexagrammaton Deathwing - Dreadwing - Firewing - Ironwing - Ravenwing - Stormwing
Allies: Space Marines - Primaris Marines
Forces of the Grey Knights
Command: Brotherhood Champion - Grand Master - Librarian
Techmarine - Chaplain - Apothecary
Troops: Grey Knight Paladin - Interceptor Squad - Justicar
Purgation Squad - Purifier - Strike Squad - Terminator Squad
Walkers: Dreadknight - Doomglaive Dreadnought - Venerable Dreadnought
Vehicles: Land Raider (Land Raider Crusader - Land Raider Vortimer)
Rhino - Razorback (Razorback Vortimer)
Flyers: Stormraven - Stormtalon - Stormhawk - Thunderhawk
Spacecraft: Aquila Lander - Boarding Torpedo
Drop Pod - Space Marine Landing Craft
Allies: Inquisition - Sisters of Battle