Warhammer 40,000


 * In the grim darkness of the far future, there is only war!

Warhammer 40,000, also referred to as Warhammer 40k or sometimes just 40k, is a continuum based on the popular tabletop game released by Games Workshop.

The game was originally a rather blatant futuristic expy of the Warhammer series by the same company (as evidenced by most of its races being describable as "X in Space"), but has since grown into its own canon with a uniquely dark and gritty feel, commonly referred to as "grimdark".

More detailed information about the setting can be found at the Lexicanum.

Setting
The game is based on the premise that in the 41st/42nd millennium (hence the 40,000), humanity has spread out across the stars&mdash;and promptly come under attack on all sides (including from itself).

Humanity is technically ruled by the God-Emperor of Mankind; however, he is almost dead and only sustained by the great Golden Throne in which he is interred, unable to move or speak, having been mortally wounded by his favored son Horus 10,000 years earlier. Only his sheer force of will has kept him "alive" for so long. In practice, the Imperium is ruled by the Senatorum Imperialis, the twelve High Lords of Terra, and functions as a totalitarian religious state where heresy is punishable by death. To make matters worse, there have been hints that the Emperor's life-support has begun to falter, and when he finally dies, humanity will be doomed, since the Emperor's power is the only thing that makes faster-than-light travel possible without getting lost in the Warp (and subsequently being torn apart by its monstrous inhabitants).

Most of the Imperium is dystopian, hence the "grim darkness of the far future." The Empire is so massive and sprawling that it includes countless different worlds of all types, ranging from Neolithic jungle death worlds, like Catachan, to polluted hive worlds, like Armageddon.

The Adeptus Mechanicus, the Tech-Priests of Mars, are the engineers and technicians of the Imperium. They create most of the Imperium's more advanced machinery and weaponry, among other things, despite the fact that their understanding of the technology they use is limited at best, with much of their procedure based on ritual and religious dogma rather than genuine engineering or mechanical skill. Actual invention is discouraged, and most new technology created is simply a variation on old technology. The Imperium was originally formed by the re-uniting of the Tech-Adepts of Mars and the Emperor, before his ascension to Godhood. The alliance was dictated by their own religious doctrines in which the Emperor occupies a messianic position of authority.

The Adeptus Mechanicus believe that all knowledge already exists and that humanity only found it. They also see technology as a sort of life form, preaching that the Imperium's machines possess a sort of spirit known as "machine spirit" which only serves humanity.

Most ordinary humans don't understand technology at all and assume it is some type of magic.

The Imperium is surrounded by numerous alien species, and is also subject to massive Black Crusades from the forces of Chaos.

The Imperium of Man
The Imperium's defense forces consist of:


 * The Imperial Guard, hundreds of billions of conscripts who hold the line against the Imperium's enemies, usually at the cost of an appallingly large number of casualties. A particularly notable position in the Guard is the Commissar, who ensures morale stays high by executing anyone who shows fear, attempts to retreat without being ordered to do so, or otherwise expresses ideas that could be considered heretical.
 * The Imperial Navy, which navigates the Warp and keeps the connections between the countless worlds relatively safe, with "relatively" being the key word.
 * The Adeptus Astartes, a.k.a. the Space Marines, who are the power-armored special troops of the Imperium. They are implanted with the chapter's gene-seed and through chemical treatment, implantation of multiple synthetic organs, and hypnotherapy they become living weapons platforms that are barely recognizable as human. There were originally twenty legions of Space Marines, each led by one of the Primarchs- genetically augmented "sons" of the Emperor specifically designed to act as his generals. Of these legions, two have no known records. Of the remaining eighteen, nine betrayed the Imperium and became the Chaos Space Marines in the Horus Heresy, (named after the Primarch Horus, the Emperor's favorite son and formerly the Warmaster of the Imperium. Most of the remaining loyal legions (and all Space Marines created after these legions) are split into 1000-man Chapters, to limit the possible spread of heresy. The original Legions are as follows:
 * I: The Dark Angels, derived from the Primarch Lion El'Jonson. Half of the Legion fell to Chaos during the Heresy, and the other half has become obsessed with hunting the traitors down to prove their loyalty to the Emperor.
 * II: All data expunged from Imperium.
 * III: The Emperor's Children, derived from the Primarch Fulgrim. Their perfectionist tendencies left them vulnerable to the temptations of Slaanesh, and now revel in forms of hedonism best left to the imagination.
 * IV: The Iron Warriors, derived from the Primarch Perturabo. Masters of siege warfare, their resentment at constantly being forced into garrison duty led them to turn against the Imperium out of spite.
 * V: The White Scars, derived from the Primarch Jaghatai Khan. Essentially Space Mongolians who ride attack motorcycles instead of horses.
 * VI: The Space Wolves, derived from the Primarch Leman Russ. Space Vikings famous for their ferocity in battle as well as their distrust of authority.
 * VII: The Imperial Fists, derived from the Primarch Rogal Dorn. The most steadfast of the Legions, their skill in forming fortifications led them to become rivals with the Iron Warriors.
 * VIII: The Night Lords, derived from the Primarch Konrad Curze. Their proficiency in terror tactics led to their ostracism from the other Legions and eventually resulted in their fall to Chaos.
 * IX: The Blood Angels, derived from the Primarch Sanguinius. Though Sanguinius's martyrdom at the hands of Horus guaranteed the Blood Angels' reputation as the noblest of the Legions, their members are afflicted with a literal bloodlust known as the Red Thirst that can eventually consume them. In addition, the psychic imprint of Sanguinius' death caused a condition called the Black Rage; those affected by it begin to hallucinate that they are Sanguinus during his last battle, which inevitably drives them mad.
 * X: The Iron Hands, derived from the Primarch Ferrus Manus. With an interest in cybernetics bordering on unhealthy levels, it is no surprise that they are closely aligned with the Adeptus Mechanicus.
 * XI: All data expunged from the Imperium.
 * XII: The World Eaters (formerly the War Hounds), derived from the Primarch Angron. Although they were always considered to be unusually violent compared to the other legions, their fall to Khorne has reduced them to psychotic berserkers who will turn on each other if there isn't anything nearby for them to kill.
 * XIII: The Ultramarines, derived from the Primarch Roboute Guilliman. The most famous of the Space Marines (both in-universe and in the real world), their Primarch wrote the Codex Astartes that serves as the inspiration for the organizational doctrines of many of the existing Space Marine chapters.
 * XIV: The Death Guard (formerly the Dusk Raiders), derived from the Primarch Mortarion. Formerly known for their durability, they have become little more than blobs of rotting flesh after they turned to Nurgle.
 * XV: The Thousand Sons, derived from the Primarch Magnus the Red. Once revered as scholars and masters of psychic abilities, they were manipulated by Tzeentch and now act as his favored pawns.
 * XVI: The Black Legion (formerly the Luna Wolves and the Sons of Horus), derived from the Primarch Horus Lupercal. After their initial defeat in the Horus Heresy, they regrouped under Horus' second-in-command Abaddon the Despoiler and swore revenge against the Imperium. Since then, they have become the leaders of the Chaos Space Marines (as far as a group of insane killing machines can be said to have a leader).
 * XVII: The Word Bearers (formerly the Imperial Heralds), derived from the Primarch Lorgar Aurelian. When the Emperor rebuked them for their worship of him (he was trying to stamp out religion of all types at the time in the hopes that it would weaken Chaos- needless to say, it didn't work), the Chaos Gods exploited their religious fervor and convinced the Word Bearers to start worshipping Chaos, making them the first Legion to fall.
 * XVIII: The Salamanders, derived from the Primarch Vulkan. Their skins may be as black as the void of space, but they retain the compassion and love of humanity that many of their fellow Space Marines have lost.
 * XIX: The Raven Guard, derived from the Primarch Corvus Corax. Experts at stealth and guerilla warfare, they were nearly wiped out during the Horus Heresy and are still trying to recover from their losses.
 * XX: The Alpha Legion, derived from the Primarch Alpharius (along with his identical twin brother Omegon, who nobody knows about). Almost nothing is known about this secretive Legion, save for the fact that it fell to Chaos. And even that part has been hotly debated at times.
 * The Adeptus Custodes, the Emperor's bodyguard.
 * The Adeptus Arbites, the police force of the Imperium. Think of them as being Judge Dredd and you'll have a good impression of their standard operating procedure.
 * The Inquisition, an organization with almost complete authority dedicated keeping the Imperium clean of Chaos, heretics, and aliens. The Inquisition maintains a force of Inquisitorial Stormtroopers. There are three branches, each with their own specialist force. These are:
 * The Ordo Xenos, which "handles" alien entities like the Tau. They control the Deathwatch, Space Marine veterans chosen for their experience in killing xenos. A Deathwatch Marine knows everything about fighting the species of xenos he's been assigned to fight, and knows all about how his chosen weapon works.
 * The Ordo Hereticus, which deals with heresy against the Emperor and the Imperium in general (a surprisingly broad field which usually ends up meaning "any element in Imperial society which isn't perfectly loyal in every concievable way"). Their primary force is the Adepta Sororitas, a.k.a. the Sisters of Battle, female warrior-nuns of the Imperial Cult.
 * The Ordo Malleus, which handles demonic forces like the Warp and the Chaos which has spawned from it. The Grey Knights, an all-psychic force of Space Marines with the best equipment in the Imperium, are the main force of this branch.

The Rest
The enemies of the Imperium include:


 * The renegade forces of Chaos - crazy mutants, daemons, and traitors worshiping the Ruinous Powers. Chief among the Chaos gods are: Khorne, the Blood God who revels in death and destruction; Tzeentch, the Changer of Ways, who is always plotting something, but his plans are so numerous, complex and self-defeating that only he knows his final goal; Nurgle, the Great Lord of Decay, who could be compared to Santa Claus if it weren't for the fact that he gives out horrifyingly nasty diseases instead of toys; and Slaanesh, the hedonistic and androgynous Prince/Princess of Excess who is pretty much the living embodiment of squick. Whenever they are not fighting the Imperium or any of the other races, they fight amongst themselves in an endless battle for supremacy.
 * Eldar - the remnants of an ancient elf-like race which directly created the Chaos God Slaanesh through several millenia's worth of unspeakable acts of debauchery and are now constantly trying to stay one step ahead of him/her/it. They have a complicated relationship with the Imperium in that while the Eldar are Xenos and must be stamped out, they know a lot about Chaos and the galaxy in general, so Imperial Commanders will, on very rare occasions, join forces with them. Similarly, the Eldar look down on other races as uncivilized "mon'keighs", but their desperate circumstances force them to work alongside (or at least manipulate) them in order to survive. Most of the Eldar live on planet-sized spaceships called Craftworlds, but a handful of them have hidden away on colonies formed before Slaanesh came into existence.
 * The Dark Eldar - a rogue group of Eldar who constantly commit acts of depravity in order to prevent Slaanesh from eating their souls, namely by taking the souls of those they kill.
 * The Tyranid Hive Fleets - heavily armored insect monsters capable of adapting to any threat they encounter. They devour entire planets, including the atmosphere and the crust. And it's implied that they're fleeing from something even worse.
 * Orks - big, green, and nasty. The most numerous species in the galaxy by far; the only reason they haven't banded together and easily crushed all opposition is the fact that they tend to spend more time fighting each other. Literally an entire species of biological weapons, created specifically by an ancient race called the Old Ones to fight against the Necrons. They possess a gestalt psychic field called the WAAAGH! that allows most of their technology to work despite it simply not being in working order (guns will fire without firing pins, cars will function with broken engines, and so on) Occasionally, it can even allow Ork technology to directly defy the laws of physics and common sense (such as the common practice of painting vehicles red as a result of the belief that "Da red wunz go fasta!"; because of the WAAAGH!, they actually go faster because the Orks believe that's what should happen) . The WAAAGH! is also a time when Orks actually band together to fight other races in a mass migration/holy war/looting party/bar-fight that only ends when the WAAAGH! leader is killed or when there's no one else left to fight with. Orks are asexual and reproduce by giving off spores that terraform any viable terrain into specially designed ecosystems capable of "growing" new Orks within months. Entire star systems have been overrun by Orks because of this.
 * The Tau Empire ("Space commies") - blue-skinned aliens with very powerful technology, probably the closest thing to "good guys" in the entire setting, and even then that's if you ignore the allegations of forced sterilization, concentration camps, and brainwashing. Like the Eldar, they are sometimes allies of the Imperium, and aside from the Damocles and Nimbosa crusades there is usually a truce of sorts between the two empires.
 * The Necrons - creepy robots which are virtually indestructible and want to subjugate and harvest all life. They used to be an incredibly short-lived race called the Necrontyr, but gave their souls and bodies to the C'tan star gods in exchange for immortality during a war with the Old Ones. They "won," but that came at the expense of becoming mindless slaves to said star gods for all eternity.

To be a man in this continuum is to be one of countless trillions, and probably very dead. Or worse.

In Badfic
In the grim darkness of the future, there is only war... and fetish fuel.

The demographics of "people interested in Warhammer 40K" and "people who write fanfiction" don't overlap much, but the canon still has considerable amounts of badfic. Many of these are straight-up porn, using the various super-soldier/alien/transformative aspects of the canon (often quite badly) in the service of the author's personal fetishes. The other most popular form of badfic is your bog-standard godmode!Sue, who tends to be depicted as a Space Marine due to their prominence within the canon.

It should be noted that due to the large number of official writers that have contributed to the setting, nothing can truly be described as canon, although continuity and consistency still exist. In-universe, this is explained by the fact that the information about the setting frequently comes from unreliable sources (such as Imperial propaganda).

Agents from Warhammer 40k

 * Durran Mkellin (Imperial Guard; Tanith First-and-Only)
 * Kilroy Vincentus (Inquisitor; Ordo Malleus)
 * Possibly Richi, judging by her use of the Tanith obscenity/blaspheme "Feth," but this isn't known for sure.
 * Rose Marcone (unknown)
 * Thoth (Astartes; Thousand Sons)
 * Zodfang Gobrunt (Ork)