While the present-day [[Characters/Warhammer40000Imperium Imperium]] consists of a large number of factions, the following are the most well-known.

!!Factions with their own pages:

* [[Characters/Warhammer40000Astartes Space Marines]]
* [[Characters/Warhammer40000ImperialGuard Imperial Guard]]
* [[Characters/Warhammer40000Mechanicus The Adeptus Mechanicus]]
* [[Characters/Warhammer40000Sororitas Sisters of Battle]]
* [[Characters/Warhammer40000Inquisition The Inquisition]]

!!Other factions


[[folder:The Officio Assassinorum]]
[[caption-width-right:350:Clockwise from top left: Eversor, Vindicare, Culexus, and Callidus assassins]]

->''For those that defy the Imperium, only the Emperor can judge your crimes. Only in death can your receive the Emperor's judgement.''

The Officio Assassinorum (Office of Assassins) is one of the Imperium's most closely guarded secrets. Consisting of a series of Temples on Terra, each one dedicated to creating and training its members in a particular style of wetwork, the Assassins work in stealth and subterfuge, slaying enemy targets and (it's rumored) Imperial targets who have exceeded their bounds. The Grand Master of the Assassins is one of the High Lords of Terra.

The Temples of the Assassins are:

* '''Callidus''': Specializing in infiltration, subterfuge, and impersonation
* '''Culexus''': Dedicated to eliminating psykers
* '''Eversor''': Berserkers used for shock and awe assaults
* '''Vanus''': Data gatherers and manipulators ''par excellence'', skilled in using other people to make their kills
* '''Venenum''': {{Master Poisoner}}s
* '''Vindicare''': Peerless snipers and sharpshooters.

Of these temples, the Callidus, Culexus, Eversor, and Vindicare are represented with models for the game.

''Codex: Assassins'' was released for the 2nd and 3rd edition 40K rules. An ''Officio Assassinorum'' dataslate was released in 2014. ''Assassinorum: Execution Force'', a board game pitting all four major assassin types against Chaos Space Marines, was released in 2015. The new Assassin models featured in ''Execution Force'' were later released as individual models.

!!Tropes pertaining to the Assassins:

* AbnormalAmmo: Vindicare assassins are equipped with a variety of specialized shells used in their Exitus weapons. Expensive and very rare, these shells are capable of [[ArmorPiercingAttack one-shotting a tank]], nullifying DeflectorShields, or injecting the target with a [[UniversalPoison lethal neuro-toxin]].
* AbsurdlySharpBlade: The C'tan Phase Weapons, used by the Callidus Assassins to cut through absolutely anything.
* AntiMagic: The specialty of the Culexus. In addition to them being able to mess with psykers just by being near them (due to the Pariah gene), the Animus Speculum weapon mounted on their helms draws power from nearby psykers to shoot bolts of anti-psychic energy that are especially lethal to psykers. In-game, they have the Psychic Abomination rule which severely cripples psykers.[[labelnote:Specifics]]''All'' psykers within 12" of the Culexus get a -3 penalty to their Leadership and don't generate Warp charges during the psychic phase. Also, the Culexus can't be targeted by psychic powers, and units that move into that 12" range lose psychic buffs or penalties.[[/labelnote]]
* AmazonBrigade: The vast majority of Callidus assassins are female, as Polymorphine works better for women.
* BadGuysDoTheDirtyWork: The Assassins were founded so that The Emperor would never have to get his hands dirty. They also have vaults containing forbidden alien technology which the Adeptus Mechanicus would consider heretical.
* TheBerserker: Eversors, who are [[ExplosiveOverclocking pumped so full of performance-enhancing combat drugs that their bodies explode if the drug flow stops]]. Because [[PsychoSerum these drugs enhance lethal aggression]] and cannot be shut off without killing the addicted assassin, [[SealedBadassInACan putting them into cryo-stasis]] is necessary to keep them alive between deployments.
* BloodyMurder: This is the inevitable result of using Eversors; ''anything'' in their path that can't stop them is guaranteed a violent, messy death, and the things that do stop them often get the same (see TakingYouWithMe below).
* BrainComputerInterface: Vanus assassins are equipped with specialized augmetics that increase their brains' ability to absorb data, essentially turning them into human computers.
* BrainwashedAndCrazy: Some of the more... "[[AxCrazy volatile]]" Imperial assassins are subject to this, being mindwiped after every mission and having their next mission subliminally programmed into them while kept sedated. Eversors are a common example, though this is not necessarily limited to them.
* CharlesAtlasSuperPower: While there is some element of augmentation common to many assassin temples, much of an assassin's abilities come from their long TrainingFromHell as much as anything else.
* TheChessmaster: The Vanus Temple consists entirely of these. As one of their members said, 'the cleanest kill is one that another performs in your stead with no knowledge of your incitement'.
* ColdSniper [=/=] ImprobableAimingSkills: Assassins of the Vindicare temple are expert marksmen and infiltrators, complete with special guns and ammunition allowing them to potentially one-shot a tank from kilometers away. They are currently the only units in the game that allows the player to pick the target (as oppose to letting the opponent or randomised methods).
* CoolHelmet: Culexus assassins have virtually all their equipment mounted in their helmet. Said helmet is necessarily so over-sized to accommodate this that one speculates they get neck-reinforcing augmentations to wield it effectively.
* EyeBeams: Culexus assassins' primary weaponry are built into their skull-shaped helmets, with point of discharge being mounted over the eyes. [[DeadlyGaze Their looks can literally kill.]]
* IWorkAlone: Assassins are deployed at maximum number of three and they never work with anyone else.
* KillAndReplace: Callidus assassins not only kill their targets, they frequently assume their roles and duties in order to cause subtle disruptions and destablize the entire operation.
* MasterPoisoner: The specialty of the Venenum Temple.
* MurderInc: The Officio Assassinorum provides elite assassins used by Imperial organizations such as the Inquisition. The Grand Master of Assassins, the head of the Office, is one of the High Lords of Terra, and is heavily monitored by the other High Lords, as the Grand Master could (and at one point did) easily wipe the others out.
* OurFounder: The Assassin Temples are named after the people who built them.
* OurSoulsAreDifferent: Culexus assassins are horrifying creatures that seem to lack a soul, thanks to the Pariah gene. Ordinary people find them [[BrownNote quite disturbing]], but the assassins are trained to [[MageKiller prey on enemy psykers]], who are especially sensitive to them. Their wargear fires what has been described as bolts of [[AntiMagic anti-soul]].
* PsychoPrototype: Legienstrasse, the lone assassin created by the now-defunct Maerorus Temple, went rogue and took an ''insane'' amount of effort to kill, including multiple attempts by the Space Marines, Inquisition, and other Assassin temples.
* RuleOfSeven: There are seven Assassin Temples.
* ShapeShifter: Callidus assassins have access to Polymorphine, allowing them to disguise themselves as a member of just about any race. They are employed to infiltrate enemy organizations, supply them with false intelligence or bad advice, and surgically remove the leadership.
* SkullForAHead: Eversor and Culexus helmets resemble glaring skulls.
* SpyCatsuit: The stereotypical garb of an Imperial Assassin is a layer of "synskin", a kind of semi-organic body sheath applied directly over the assassin's flesh. Multiple variations of it exist, some of which enhance strength, others of which have chameleon qualities, and some are capable of changing shape (along with the wearer).
* StraightForTheCommander: During the 32nd millennium, Drakan Vangorich (then-Grand Master of the Assassins) orchestrated the deaths of all the other High Lords in a bid to take control of the Imperium. He was eventually killed by a Space Marine strike force, but not before an extremely bloody conflict.
* SuperReflexes: Imperial Assassins of all stripes have their reflexes trained to such a level that they can literally DodgeTheBullet in combat.
* TakingYouWithMe: The Eversor assassins, in addition to their [[ExplosiveOverclocking dangerously unstable cocktail]] of [[PsychoSerum chemical enhancements]], also have two-part explosive chemicals in their body. As long as their heart keeps circulating blood, the two parts will not come into contact, but once the Eversor is killed the blood stops circulating and the chemicals join, causing the assassin to explode and ensure that their target is killed even if the Eversor only survives long enough to get near the target.
* TrainingFromHell: All Assassin candidates are selected as children and go through 10 years of harsh, intensive training just to become novice assassins, with tests and trials continuing throughout their lives.
* WhoWatchesTheWatchmen: This happens in two different ways:
** The Inquisition's Ordo Sicarius monitors the Assassins to keep another major power grab from ever happening.
** Certain elements of the Inquisition have secretly sought ways to police or even eliminate the Space Marines, and the Assassins are privy to these machinations.

[[folder:The Adeptus Arbites]]
[[caption-width-right:232:Ego legis sum.]]

->''To serve the Emperor. To protect His domains. To judge and stand guard over His subjects. To carry the Emperor's law to all worlds under His blessed protection. To pursue and punish those who trespassed against His word.''

The Adeptus Arbites are the enforcement arm of the Adeptus Terra. It is they who ensure that Imperial laws and Administratum decrees are followed, and most importantly, that the Imperial Tithe is met. Most Imperial worlds of any significance at all will have an Arbites precinct house somewhere, and larger worlds will have several. Local crime is beneath their general jurisdiction (that falls to local planetary law enforcement) but they help track crime that spans multiple worlds and violates laws from authorities beyond that of the local government. When rabble-rousing citizens get in the way of the Imperial tithe being fulfilled, the Arbites are summoned to break them up and suppress riots. If it goes so far that a planet goes into full rebellion, the Arbites are the ones expected to be a loyalist holdout, sealing their precinct houses for siege and getting the message out to the wider Imperium.

The Adeptus Arbites have never had a full published codex book, only unit information and models in various additions released as supplements or as allies for other Imperial forces. For the most part though, they are almost never seen in the tabletop game itself, but they are well-represented in the fiction.

!!To be just, our tropes must be cruel:

* AwesomePersonnelCarrier -- Arbiters used variations of Standard Template vehicle patterns, such as Chimeras and Rhinos. In particular, they often use the Repressor pattern of the Rhino chassis, which has an extended transport bay with additional firing slits for riot suppression. They are especially fond of these because the wide surfaces and heavy armor make it an excellent mobile blockade.
* ByTheBookCop -- Arbites are selected very carefully for those who will take their duty extremely seriously, many of them coming from the same [[BoardingSchool Schola Progenium]] programs that train [[ThePoliticalOfficer Commissars]] and [[EliteMooks Storm Troopers]]. One who goes CowboyCop on them will find themselves hauled before a panel of their comrades to answer for their behavior.
* CarryABigStick -- Power Mauls are common weapons for Arbiters to be equipped with, taking the form of large truncheons. They mount a power field generator with adjustable power settings. At low levels, they function as a [[StunGun Stun Stick]], while at higher levels they can [[ArmorPiercingAttack shatter armor under impact]].
* {{Expy}} -- Go look up what "[[Comicbook/JudgeDredd ego legis sum]]" translates to.
* HeavilyArmoredMook -- The Arbites tend to wear carapace armor, which is about the best purely physical protection the Imperium can provide short of PoweredArmor. Among the Imperial Guard, this armor is restricted to only heavy infantry or elite forces, but the Arbites mission scope requires them to be more survivable and put their own equipment at less risk anyhow.
* JudgeJuryAndExecutioner -- On an institutional level, the Arbites are charged to hand out justice without being accountable to other local agencies, though they are expected to do so only within the strictest interpretation of law and precedent. For the most part though, these roles are divided up between members of the organization, being the role of "Arbiters" to bring in suspects and "Judges" to sentence them.
* JurisdictionFriction -- Happens very infrequently, if only because the Arbites automatically override local jurisdictions, and few would dare challenge them on that. That said, it is often inverted in that Arbites are not charged to investigate lesser crimes, and it often takes pleading on the part of the local enforcement agencies to get the Arbites involved in the first place if they can be convinced that the crimes are sufficiently disruptive to the normal flow of business.
* NonLethalWarfare -- While they are willing to use deadly force, their mission typically involves battering down agitating elements rather than killing them outright. Not that this makes their employment any more family-friendly, said non-lethal warfare typically involves lots of clubbing, shocking, broken bones, and chemical-burned mucus membranes.
* PoliceBrutality -- The Lex Imperialis overrides any local law, which means that if an Arbiter has accused you of a crime, ''you have no rights''. Incidentally, obstructing Arbiters fulfilling their duty is a crime, stay the heck out of their way. "Always err on the side of harshness," is sanctioned policy, after all...
* RobotDog -- Cyber-Mastiffs, a kind of servitor made from canines. They are used to help Arbiters hunt down hiding criminals, where their robotic components make them more reliable, more durable, and better trackers than their purely organic counterparts.
* ShieldBash -- Arbiters often wield suppression shields for this very purpose. In addition to [[LuckilyMyShieldWillProtectMe functioning as personal protection]], the suppression shield contains [[StaticStunGun an electrical discharge unit that can incapacitate anything]] struck by (or striking) it.
* ShotgunsAreJustBetter -- Shotguns are another common piece of equipment for Arbiters. Mainly because most of what they go up against are expected to be more lightly armed and armored than them, but also because a shotgun provides a great deal of versatile utility with different kinds of specialized shells.
* StateSec -- To a lesser degree, but greater visibility, than the Inquisition. Each precinct house is equipped to fight a small war, with vehicles, weapons, and barracks housing the Arbiters to use them. They even have a few of their own space ships, though these are (relatively) small patrol cruisers used for things like customs enforcement.


[[folder:Imperial Knights]]

->''Fealty, Honour and Duty''

The Imperial Knights are a sub-empire within the Imperium, rulers of their own private feudal planets known as Knight Worlds. Closely allied to the tech-priests of the Adeptus Mechanicus, the Imperial Knights pilot massive mechanized war machines of such stature and fury that a single one can change the course of a war. Bound by ancient oaths that tie them to the Imperium, the Imperial Knights seek to fight the enemies of Man, wherever they may be found. Numerous varieties of Knights exist, with the most common being the [[JackOfAllStats generalized]] Knight Paladin and the melee-oriented Knight Errant.

Originally a force in games of ''Epic'', Knights were largely confined to fluff for a number of years before they were reintroduced into ''40k'' proper in 2014. Their 7th edition codex was released in 2015.

!!Imperial Knights Tropes

* AuthorityEqualsAsskicking: The most skilled and deadly Knights can become Knights Barons, leading contingents of Knights into battle and getting custom Knight suits with better weapons.
* BladeOnAStick: Some Knight variants carry Power Lances. The Cerastus Shock Lances carried by Knights Lancers double as [[BoomStick Boom Sticks]].
* BoringButPractical:
** The Imperial Knights are actually easy to mass produce and require only a single operator, as opposed to the centuries it takes for a Forge World to build even one Warhound Titan, not to mention the training the Princeps and his crew requires. This allows them to be far more ubiquitous than the larger Titan Legions, despite each individual Knight packing less firepower.
** Compared to some of the more esoteric weapons that other Titans pack (among them a missile that tears a ''NegativeSpaceWedgie'') Imperial Knights bring humble battle cannons and melta cannons to battle. But while these weapons lack special rules or flair, they get the job done by [[MoreDakka simply drowning the opposition in sheer firepower]].
* ChainsawGood: Reaper Chainswords, a smaller version of the kind used by Titans, which can cut through enemy bunkers with ease and open tanks like tin cans.
* FeudalFuture: Even more so than usual in the setting. Society on Knight Worlds is divided between the serf-like Drovers, who tend to herds and crops and are equipped with simple unarmed walkers; the Sacristans, a subset of the Mechanicus who look after the mecha and keep the peace between noble houses; and the Knightly Houses proper, who have exclusive access to the HumongousMecha and use these to rule their worlds, and who are sworn to a number of high lords, who in turn answer to a single Princeps or High King. In turn, each Knight World is sworn to either Terra or Mars.
* HumongousMecha: Not quite as gigantic as the Titans fielded by the Adeptus Mechanicus, but still significantly larger than [[MiniMecha the Sentinels]] the Imperial Guard uses.
* LightningBruiser: Knights Lancers, a rare type of Knight suit notable for being much faster and more powerful than other kinds, in addition to having [[BladeOnAStick better]] [[BoomStick close-combat]] [[LuckilyMyShieldWillProtectMe weapons.]] The main reason they’re only used as scouts and flankers instead of being the default type is because they’re too difficult to manufacture to make in large numbers.
* LowCultureHighTech: Even by this setting's standards. The Knight Worlds are generally on a medieval tech level, apart from the Knights and any other toys the Adetpus Mechanicus feels like giving the local rulers.
* MightyGlacier: The Knights Crusaders and Castellans are bulkier, slower and less nimble than other varieties, but pack increased firepower and armor to compensate.
* PowerFist: The massive Thunderfists the new Knights have access to are this, which beats out the old Reaper Chainsword.
* SwordAndGun: The two most common varieties of Knight, the Knight Paladin and the Knight Errant, have a [[ChainsawGood chainsword]] mounted on one arm and a gun on the other.
* TotalPartyKill: In-game, when a Knight is dealt enough damage to Explode, the diameter of its blast is ''15 inches''[[note]]to put that in perspective, most vehicles' blast covers 1-6" from the edge of the hull[[/note]] and can scatter (representing the Knight staggering and falling), so it has the potential to take out a large chunk of your army if it goes boom.

[[folder:The Adeptus Custodes]]

The Adeptus Custodes (The Guardians, Watchers of the Throne, The Thousand Companions) are the guardians of the Imperial Palace and the Golden Throne, as well as being the personal bodyguard of The Emperor.

* AwesomeButImpractical: Invoked in-universe. While each Custode is an undisputed badass even by 40k standards, they are exceedingly expensive to produce. Each Custode requires roughly the same cost as a whole ''Astartes Chapter'' and while a single Custode is to an Astartes as an Astartes is to an Imperial Guardsmen, it's simply easier to drown the enemy in corpses (this being 40k and all). Thus they are allowed to remain the Emperor's praetorian guard simply because it's not feasible to use them for any other purpose.
* BladeOnAStick: Custodes wield Guardian Spears as their WeaponOfChoice.
* BodyguardingABadass: Custodes protected the mightiest human who ever existed.
* CombatPragmatist: Custodes are versed in politicking, spycraft and even assassination; skills no self-respecting Astarte would learn.
* EarnYourTitle: Names are the only reward Custodes have for serving the Imperium. A Custodes with an OverlyLongName is not to be trifled with.
* GateGuardian: Only The Custodes can allow anyone in The Emperor's presence.
* InterserviceRivalry: Many Space Marines envy the Custodes for being so close to The Emperor.
* PaintItBlack: Black became the Custodes color to mourn The Emperor.
* PraetorianGuard: The Custodes defend The Emperor even long after his internment in the Golden Throne.
* ShirtlessScene: The Custodes abandoned armor after the Heresy.
* SmallRoleBigImpact: The Custodes singlehandedly ended the Age of Apostasy first by talking the Brides of the Emperor into turning against Goge Vandire, then convincing (or scaring) Sebastian Thor into becoming the new Ecclesiarch.
* SuperPrototype: Of the Space Marines.
* UndyingLoyalty: To The Emperor, whose corpse they still guard.

[[folder:Mutants and Abhumans]]

->''Twisted flesh, twisted soul.''

The Imperium does not simply worship the Emperor, but also the holy human form. Part of the Imperium's UsefulNotes/ManifestDestiny states that humanity has a right to rule the galaxy. However, the simple fact is that after thousands of years on other worlds, various human populations have evolved into different types of humans. These are referred to as Abhumans or Mutants, variously; Abhumans are fairly minor, stable strains of mutation that are effectively the result of natural evolution caused by different environments, while Mutants are far more bizarre in form and stem from the wide variety of genetic degeneratives at loose in the galaxy at large -- radiation, genetic warfare, toxic chemicals, ''et cetera''. While the Imperium officially disdains them, some are useful or even necessary. In the time of the Emperor, the view of Abhumans and Mutants was more lenient, but after ten thousand years, the Imperium has taken a more draconian approach.

In the background, the most important of mutants are the Navigators, families who were genetically engineered in the distant past to navigate the Warp with psychic powers. Collectively, they form the Navis Nobilite, wealthy families who are necessary for the Imperium to survive. On the tabletop, certain Abhumans are useful to the Imperial Guard for specialist skills. Mutants, in the background and to an extent on the tabletop, are typically executed on sight for their genetic damage or kept as slaves -- as a result, they are eager worshipers of Chaos, aided by the fact that Chaos tends to both cause mutation in its followers and treats those bearing mutations as being blessed by the Gods.

!!General Abhuman and Mutant tropes

* TheAtoner: Beastmen who followed the Imperial Cult were ruthless in purging the Emperor's enemies as penance for the "sin" of mutating.
* BodyHorror: Generic mutants. Even those who haven't been touched by Chaos can sport all manner of strange and unnatural features, including but not limited to: extra eyes/mouths/limbs, rotting flesh, atrophied bodyparts, unnaturally swollen musculature, oversized bodyparts, scales, fur, fangs, claws, slime-oozing skin, blisters and warts, tentacles... Essentially, a mutant is living BodyHorror and may or may not have {{Lovecraftian Superpower}}s as a result of it.
* ChuckCunninghamSyndrome: Originally, many Abhumans were transplants from ''TabletopGame/{{Warhammer}}'', but as time went on, they stopped being updated or even mentioned. The Squats are the most famous example of this, [[DroppedABridgeOnHim though they get a rather nasty sendoff.]]
* DumbMuscle: Increased size, strength and toughness at a cost of lowered intelligence is a fairly common mutation. Some, however, are bigger, stronger, and tougher than regular humans while [[GeniusBruiser being just as smart or smarter than humans]].
* EvilAlbino: Downplayed with the Afriel Strain, a failed experiment in creating non-Space Marine super soldiers. Not only are they albinos, they have horrible luck.
* ExtraEyes: They're a common mutation, and [[EyesDoNotBelongThere can turn up in the strangest places]].
* FantasticRacism: The Imperium typically takes a very dim view of mutation from the accepted norm of the "Holy Human Form", though the degree to which a typical citizen subscribes to this will vary. One major reason for this is that mutation is often a sign that one is becoming [[TheCorruption corrupted by the Warp]], potentially becoming a vessel for the Ruinous Powers. However, this hatred extends to those whose mutations are caused by more "mundane" sources, such as generations of exposure to radiation or industrial waste, leading to widespread hatred and distrust of all mutants. Since mutation can continue to appear generation after generation, killing all mutants tends to be impractical, so most are allowed to exist as an oppressed underclass, looked down upon by all.
** Abhumans are subraces of humans whose differences have manifested into stable genotypes, without the randomness seen as signs of corruption. They often suffer some prejudices related to their differences, but find a much better measure of acceptance, especially if those differences make them valuable to the Imperium in some way. Navigators in particular, while still somewhat feared, are also held in a degree of awe due to the absolutely essential role that they play in the Imperium.
* HeavyWorlder: How Ogryns and Squats came to be, even though they went in completely different directions.
* NWordPrivileges: Many refer to each other as "twists", but for a non-mutant to use that would be seen as a nasty insult.
* RadiationImmuneMutants: One of the reasons why mutants are often employed as a labor force is that they are often willing (if only grudgingly so because FantasticRacism and circumstances limit their options) to perform labor in and around whatever corrupting influence mutated them in the first place (caustic industrial chemicals, aggressive fertilizers, radiation-leaking reactors, toxin-laden mines, etc.) While they are not necessarily ''immune'' to further effects, they are already twisted beyond the Holy Human Form and a little more would hardly make things much worse for them.

!! Specific important mutants and abhumans


->''In my high seat I gaze into the immaterium and see the shadow that our own universe casts into depthlessness. This eye... this eye sees gentle flows of soul-stuff where the becalmed mind might starve to death, and tides and churns of genius and hate. The warp mocks the power of words to describe. But what I can never turn my back on is the power and the beauty of the Emperor. I see His soul shine out from Earth and His presence fill every corner of the immaterium. [...] I have known from the first time I beheld it that I could do nothing but follow that light with my life.''

The Navigators are a race of mutants that is an integral part of the Imperium's function, as their mutation allows them to actually see the fluctuations of the Warp and the light of the Astronomican, and thus guide Imperial ships (relatively) safely in Warpspace.

* ArrangedMarriage: Since Navigators can only pass on their psyker genes by procreating with other Navigators, marriages among the Navis Nobilite are arranged usually between rival houses to ensure genetic stability and as a form of alliance.
* AsskickingEqualsAuthority: When the Paternova dies, the Heirs Apparent (the most powerful Navigators of each house) become larger, stronger, and more aggressive. They then fight and kill each other for the right of Paternova.
* BlindfoldedVision: When not actively guiding a ship, Navigators will cover their ThirdEye, as [[DeadlyGaze looking into it can cause madness]]. This makes [[PowerLimiter limiting others' exposure to it]] necessary. This covering can take many forms, from a headband, to a veil, to an {{eyepatch|OfPower}}, to [[InTheHood a low-pulled hood]], or even occasionally [[ElectronicEyes a cybernetic shutter-like metallic eyelid]].
* BodyHorror: Thanks to a limited breeding pool, the possibility of imperfect genetic tampering on the part of some ancestors, and generations of necessary warp exposure, Navigators often suffer from a variety of minor mutations. As Navigators age these mutations become more obvious and extreme, with some of them even transforming into ugly frog-octopus things. It's an accepted fact of life for them and even during the brutal inter-house coldwars both sides will respect this secret and ensure that nobody breaks the {{masquerade}}. The Emperor was aware of these mutations but decided to tolerate them.
* DeadlyGaze: Staring into a Navigator's Warp Eye is commonly said to [[BrownNote cause either insanity or death]]. No one wants to test it, and Navigators must wear hoods, scarves, or headbands of [[AntiMagic psyk-resistant]] material around normal humans.
* ExtraEyes: Navigators possess a "Warp eye" allowing them to see the currents of the Immaterium and guide ships through it. This is not a poetic turn of phrase.
* FeudingFamilies: Among the Navis Nobilite, there exist conflicts known as Tradewars, which include limited conflict among the families. The Administratum tolerates these to a point, as long as they're short and not too destructive.
* GoMadFromTheRevelation: {{Averted|Trope}} by the Navigators when exposed to the Warp, which is what makes them unique in the setting in which this trope is otherwise played straight. Their ThirdEye allows them to perceive the Warp in a way which will not overwhelm their mortal mind, enabling their ability to guild a ship through its currents. This perception is subjective, and each Navigator will see it in a different manner, so that when they try to describe it to others, the only way they can do so is through vaguely poetic metaphor.
* ThePatriarch: The Paternova, the leader of the Navis Nobilite, who is called the "father of the Warp", and is somehow able to increase the Warp sense of his family's Navigators.
* [[WalkingTheEarth Walking the Cosmos]]: Some Navigator families abandon their wealthy estates and take to wandering the galaxy.
* WeirdnessCoupon: The Navigators are mutants whose elders begin mutating beyond the norms of the "holy human form", and yet are fantastically wealthy and have a permanent seat on the High Lords of Terra. They're so absolutely vital to star travel that they have to be given these things.

[[caption-width-right:250:Top: An Ogryn.\\
Bottom: A Bullgryn BONE'ead.]]

->''- Listen, Ordrogg, the Emperor's very pleased with all of you, OK?''\\
''- Him? He's pleased?''\\
''- Very pleased. He's watching you now. He says he wants you to go over to the Robots and stick with them. You got that?''\\
''- Yerr. On our way.''

Ogryns are an abhuman strain, the product of high-gravity worlds with barren environments. They are large, even bigger than Space Marines, but are known for being very dumb. They are commonly used in the Imperial Guard as shock troops.

* {{Adorkable}}: Despite their poor hygiene, Ogryns are generally seen as lovable goofballs by the fanbase.
* BashBrothers: When not organized into a unit unto themselves, an Ogryn will usually be paired up with a "little'un" whose job it is to stay with the Ogryn at all times and keep them pointed at the enemy during combat and make sure they do not accidentally [[TheKlutz hurt themselves]] [[AndCallHimGeorge or others]] while out of it.
* {{BFG}}: Ogryns will sometimes be employed as heavy-weapon teams, as they can easily swing around a large gun that would otherwise take two soldiers and a carriage to wheel around. Said Ogryns typically do best with weapons that have [[MoreDakka a high rate of fire]] and require [[BottomlessMagazines little or very simple reloading]] since it is easier to hold an Ogryn's interest with such a "toy" that they continue to use it to enthusiastic effect.
* CanisLatinicus: The official Ogyrn species name is ''Homo sapiens gigantus''. However, there are seven distinct types, including ''H.S. gigantus gigantus'' and ''H.S. gigantus Cranopus''.
* {{Claustrophobia}}: Commonly suffer it, with enclosed spaces making them very frightened and jumpy. A nerve-wracked eight foot tall slab of clumsy muscle is generally not a good thing...
* DumbMuscle: Ogryns are massive, powerful, and dumb, even moreso than your basic Ork Boy. During the Literature/HorusHeresy, it was said that those who fought on the Chaos side only did so because were told the other guys had betrayed the Emperor. The smarter ones are given [[BioAugmentation augmetic upgrades]] called Biochemical Ogryn Neural Enhancement ([[FunWithAcronyms BONE]]) to boost their intelligence a bit more. This allows them to become sergeants of Ogryn squads, called ''Bone'eads''.
* EvilCounterpart:
** Chaos forces also makes use of Ogryns. Ogryn Berserkers are Khornate warriors, lobotomized and driven to murderous fury by a drug called Slaught. Plague Ogryns are used by the armies of Nurgle as walking disease incubators due to their size, strength, and endurance.
** In general, "Big Mutants" tend to be depicted as being akin to Ogryns or as corrupted Ogryns.
* HumanShield: The 2014 Astra Militarum codex introduced Ogryn specialists known as Bullgryns whose functionality in the armor is to act this way. Turns out that an Ogryn inside a massive suit of carapace armor and carrying a huge tower shields, or else a force-field projecting buckler is a pretty good mobile wall. When you arm him with an underarm-slung grenade launcher, which is reinforced so it can stand up to being used as an improvised tonfa, or else with an armor-vaporizing greatclub, he can dish out a fair amount of damage, too.
* ImprovisedArmor: The front plates of Bullgryn carapace armor are made from sections of tracks from Leman Russ tanks.
* TheKlutz: Their great strength and poor self-control means that they tend to accidentally break things that they interact with, unless those things are large and reinforced. Hence why they virtually always use customized equipment.
* TheOgre: Ogryns are Abhumans who evolved on high-gravity worlds with barren environments. Unlike the Squats, who developed in roughly the same kind of environment but are much like classic dwarfs, Ogryns are huge, standing taller than even Space Marines.
* ThePigPen: Ogryns are known for being flabby and having horrible hygiene, and are often called Fats, Flabs, Slobs and Stenches as a result.
* PsychopathicManchild: Played with. Ogryn are taught to hate and kill the enemies of the Imperium, but this is usually the result of exploitation of their innocent, childlike nature more than inborn aggression.
* ShotgunsAreJustBetter: The Ripper gun is the Ogryns' standard firearm, and is used just as much as a club as a shotgun.
* UndyingLoyalty: Ogryns believe that the Emperor has personally issued them every order (being worked down from the chain of command) and thus obey orders to the best of their abilities. In a tragic demonstration of this, many Ogyrns fought on the side of Chaos during the Horus Heresy, but they didn't ''knowingly'' do so: they all genuinely believed that they were still fighting for the Emperor and the Imperium, when really it was their superiors misleading them with lies.
* UpgradeArtifact: Ogryn BONE'eads are Ogryns who have received extensive brain augmentation by the implantation of very high-quality neural implants provided by the Adeptus Mechanicus. Such implants are rare and precious, and few outside of the Cult Mechanicus are ever blessed with them, but in the case of Ogryns the Munitorium considers it worth the expense and effort to get at least one Ogryn in every group enhanced in this manner, as having a squad leader who can fully understand orders and think independently (if not particularly creatively) is a great force multiplier for Ogryn squads.
* WeirdnessCoupon: They're mutants, but they make extremely loyal soldiers who love cracking heretic and xeno skulls for the Emperor.


->''Little thieves! Thieves and vagabonds, the lot of them. They’re petty-minded, larcenous little subhuman scum to the last. Everyone overlooks it because they can shoot straight and can cook a decent meal. You can’t trust them... any of them. They’ll steal your chrono if you shake hands with them, and as likely to pick your pocket as praise the Emperor’s name...''
-->-- Anonymous Imperial Guardsman

Like Ogryns, Ratlings are an abhuman strain commonly used in the Imperial Guard. However, they are the polar opposite of Ogryns in nature and function. Of very short stature, Ratlings are used as snipers and stealthy infiltrators, and also as cooks, roles at which they excel. However, they can be a disruptive presence as well, as they're known to be hedonistic and have a streak of kleptomania.

* CanisLatinicus: The official Ratling species name is ''Homo sapiens minimus''.
* DyingRace: Ratling populations have suffered greatly due to Tyranid invasions of their worlds.
* ExplosiveBreeder: Ratlings procreate like there is no tomorrow...[[EverythingTryingToKillYou and there may not be.]]
* FantasticSlurs: Ratlings are also referred to as Runtlings, Stunties, Halflings, or Maggots.
* FriendlySniper: {{ZigZagg|ingTrope}}ed. Ratlings are gregarious, enjoy a good feast, and make excellent snipers, but ''The Imperial Infantryman's Uplifting Primer'' warns that petty crime rates and illegal gambling increase in regiments with Ratling squads attached.
* TheHedonist: Ratlings enjoy the finer aspects of life.
* {{Hobbits}}: Like Tolkien's hobbits, Ratlings are very short, compactly built, and tend to be portrayed with large, hirsute feet. They also love food, both the making and the eating.
* SupremeChef: Not exactly, but they can certainly do a lot with very little.


->''We have always been a race of traders. It is natural to us that we should trade the fighting skills of our Brotherhoods. As well as bringing us a profit, it also allows our youngsters to gain experience and honour, and to keep alive the skills which our strongholds may one day need for their own defence.''

One particular abhuman faction that has caused some controversy is the Squats. The Squats were a race of abhumans that had adapted to subterranean life on high-gravity worlds near the galactic core. Separated from mainline humanity for tens of millennia, they grew shorter and, well, squatter, eventually coming to resemble the traditional fantasy dwarf in both appearance and temperament. Due to the difficulty of living on barren planets with radioactive surface conditions, the Squats developed extremely reliable food production systems, armor, and other technology, but also had a fatalistic attitude toward life. Over time, they made contact with the Orks and Eldar and gained a reputation for their high-quality tech, shrewd business dealings, and potent military defense. Eventually they were rediscovered by and reabsorbed into the Imperium, as their tech fascinated the Adeptus Mechanicus and made them a welcome addition to the Imperial armed forces, but they maintained a high degree of autonomy.

As a game faction, the Squats were never popular, nor did they fit very well in the increasingly GrimDark setting. They were included back in the days when ''[=40K=]'' was a transparent [[foldercontrol]]

[[folder: [[Recycled In Space In Space ]]
]] version of ''TabletopGame/{{Warhammer}}'' and every race in the latter had to appear in the former, but as the setting matured the Squats felt more and more out of place. Game designers never really decided on a "tone" for the army, and depictions of them wavered between goofy space dwarfs and miniature biker dudes. In 1994, they were discontinued with the explanation that the newly arrived Tyranids had descended upon their Homeworlds and stripped them clean of all life (like they do). A handful of embittered Squats still survive spread across the vast Imperium, but as a faction they are absolutely, positively never coming back. In fact, it was once Games Workshop's official position that they won't even be ''mentioned'', although this policy has relaxed enough that the reprinted edition of ''Space Marine'' lists an encounter with Squats in the novel summary, and the 6th and 7th edition rulebooks' appendices list Squats as one of the handful of surviving abhuman strains.

Though the Squats are ''extremely'' dead, the "space dwarf" concept itself may be in for a comeback. Games Workshop has introduced a race called the Demiurg as a member species of the [[Characters/Warhammer40000TauEmpire Tau Empire]] in the ''40K'' spinoff ''BattlefleetGothic'', a species that practically never leaves their rugged ''Stronghold''-class starships, makes a living as [[AsteroidMiners deep-space miners]], are technologically-advanced enough to introduce ion cannon technology to the Tau, and closely resembles the Squats to boot. At the moment the only Demiurg models created have been for ''Gothic'', where they are the only faction said to be too small and isolationist to field actual fleets, and there are no plans to make a tabletop army for them, but only Tzeentch knows what the future holds...

* BadassBiker: Well, ''triker''. This was one of the very few unique, consistent parts of the Squats' racial identity.
* BaseOnWheels[=/=]CoolTrain: The Squat's Land Trains, which are several of these linked together to form a larger mobile structure. Usually each car would have its own specialization, such as artillery platforms or flyer landing and service pads.
* CanonDiscontinuity: Don't [[BerserkButton mention them]] at [=GW=] press events.
** This even extends to the older 40k novels - when Ian Watson's ''Inquisition War'' trilogy was re-released, Grimm (one of the main characters) was {{Ret Con}}ned from a Squat to a Techpriest.
** By 6th edition, this appears to have tapered off a bit, as the re-release of ''Space Marine'' is entirely unedited, and the 6th edition rulebook lists Squats as one of the surviving abhuman strains. The 7th edition rulebook keeps this mention.
* CanisLatinicus: The official Squat species name is ''Homo sapiens rotundus''.
* ChuckCunninghamSyndrome: It took Games Workshop a while to decide if they wanted to keep the Squats in the setting or not, which meant that there was a long period of time where there was really no word on when the next update for them was coming out until they finally made their dropping official.
* CoolAirship: The Squats were known to field heavily-armored, rigid-bodied lighter-than-air craft in battle.
* DemotedToExtra: They used to be their own army, with their own lists, units, and models, separate from the Imperium of Man but a trusted ally to it. These days they are an obscure bit of background fluff which is barely acknowledged as even being in the setting.
* [[DroppedABridgeOnHim Dropped A Hive Fleet On Him]]: When 40K decides to kill you off, you are killed off with ''extreme'' prejudice.
* DyingRace: They're still around, but their civilization is gone and the few survivors are forced to fight on as abhuman auxiliaries.
* ElvesVersusDwarves: {{Downplayed|Trope}}. The Squats used to trade with the Eldar during their Age of Isolation before the establishment of the Imperium. But when they were attacked by Orks, they sent requests to the Eldar for aid, which the Eldar ignored. Relations between the Squats and the Eldar have been cold ever since then, with the Squats regarding the Eldar as unreliable and untrustworthy.
* {{Expy}}: Of ''TabletopGame/{{Warhammer}}'' Dwarfs.
* HeavyWorlder: Strangely enough, the Imperial Guard's [[TheOgre Ogryns]] also come from high-gravity worlds, but turned out completely different. The demands of their unbreathable high-pressure atmospheres and underground warrens may have been a contributing factor to the Squats current size.
* HigherTechSpecies: The Squats were very dependent on their technology from the foundings of their Homeworlds, and lost only a small fraction of it in comparison to what the bulk of the humanity has lost from the Dark Age of Technology. Spared from the restrictions of the Adeptus Mechanicus, the Squats innovated freely, their harsh situations making such necessary. When the Imperium finally reestablished contact with them, the Squats had developed a wide variety of technologies that no one else had, such as power generators which drew directly from the warp, and neo-plasma, as well as superior metallurgy.
* JustForFun/CandleJack: An unofficial but heavily enforced rule on the old Games Workshop forums was that anyone who stated that the Squats should be brought ba
* MoodDissonance: Part of the reason Squats were problematic.
* OurDwarvesAreAllTheSame: Even in space!
* PoweredArmor: ... that makes them look like walking eggs... on bikes...
* PrivateMilitaryContractors: See the quote on WarForFunAndProfit below.
* ProudWarriorRaceGuy: Because Dwarfs are.
* RecycledInSpace: Of Dwarfs.
* ReimaginingTheArtifact: The Squats did much better in ''Epic 40,000'' than they ever did in ''Warhammer 40,000'', where the difference in scale allowed them to much better show off their potential for massive mobile construction. However, this was too little, too late to save them from slipping into CanonDisContinuity.
* TunnelKing: As a culture. The Squat Homeworlds almost never had a breathable atmosphere, and often a high pressure one at that, so the Squats became experts in underground construction and living by necessity. This in turn is part of why they were so hard to rout when invaded--their underground warrens were resistant to bombardment from above and the confined spaces would heavily favor the defenders.
* WarForFunAndProfit: Best summed up by this quote:
-->You people do well at war because you treat it as a religion. [[WarForFunAndProfit We do well because we treat it as a business]]. It is just a matter of outlook.
* WeirdnessCoupon: The Squats were only ever part of the Imperium in the most nominal sense, the Great Crusade having fought almost to a stalemate over their worlds when the Imperium tried to forcibly absorb them. The conflict was settled with a variety of treaties in which the Squats could maintain their self-governance without Administratum oversight and were allowed to maintain their own culture, only offering the Imperium their occasional effectual support. The fact that they maintain their own culture, do not report to Imperial authorities, vary from the norm of the Holy Human Form, and do not believe in the Imperial Cult would normally be seen as an unacceptable level of deviance on the Squats' part. However, this arrangement works due to the general stability of their genome, their fundamental reliability, dislike of xenoforms, and resource and technology contributions to the Imperium.