Warhammer 40,000

Warhammer 40,000 is a miniature wargame produced by Games Workshop. It is the most popular miniature wargame in the world, especially in the United Kingdom. The first edition of the rulebook was published in September 1987, and the ninth and current edition was released in July 2020.
As in other miniature wargames, players enact battles using miniature models of warriors and fighting vehicles. The playing area is a tabletop model of a battlefield, comprising models of buildings, hills, trees, and other terrain features. Each player takes turns to move their model warriors around the battlefield and pretend that they are fighting their opponent's warriors. These imaginary fights are resolved using dice and simple arithmetic.
"Warhammer 40,000" is set in the distant future, where a stagnant human civilisation is beset by hostile aliens and supernatural creatures. The models in the game are a mixture of humans, aliens, and supernatural monsters, wielding futuristic weaponry and magical powers. The fictional setting of the game has been developed through a large body of novels, published by Black Library (Games Workshop's publishing division).
"Warhammer 40,000" has spawned a number of spin-off tabletop games. These include "Space Hulk", which is about combat within the narrow corridors of derelict spacecraft, "Necromunda", which is about gang warfare in a hive city, and "Gorkamorka", which is about Ork mobs and vehicles, all of which use 28 mm miniatures. Other tabletop games set in the "Warhammer 40,000" lore include "Epic" for large scale battles including Titans, and "Battlefleet Gothic" for spaceship combat. Video game spin-offs, such as the "Dawn of War" series, have been released.
Overview.
"Note: The overview here references the 9th edition of the rules, published July 2020"
The rulebooks and miniature models required to play "Warhammer 40,000" are copyrighted and sold exclusively by Games Workshop and its subsidiaries. These and other materials (dice, measuring tools, glue, paints, etc.) all make "Warhammer 40,000" expensive as far as gaming hobbies go. A new player can expect to spend at least $400 to assemble enough materials for a "proper" game, and the armies that appear in tournaments can surpass $600.
Miniature models.
Games Workshop sells a large variety of gaming models for "Warhammer 40,000", although Games Workshop does not sell ready-to-play models. Rather, it sells boxes of model parts. Players are expected to assemble and paint the miniatures themselves. Games Workshop also sells glue, tools, and acrylic paints for this purpose. Most "Warhammer 40,000" models are made of polystyrene, but certain models which are made and sold in small volumes are made of lead-free pewter or epoxy resin.
Each miniature model represents an individual warrior or vehicle. In the rulebooks, there is an entry for every type of model in the game that describes its capabilities. For instance, a model of a Tactical Space Marine has a "Move" range of 6 inches, a "Toughness" rating of 4, and is armed with a "boltgun" with a range of 24 inches.
The assembly and painting of the models is a major aspect of the hobby. A player might spend weeks assembling and painting their models before they are all ready for play. 
Officially, "Warhammer 40,000" does not have a scale, but the models approximate to a scale ratio of 1:60. For instance, a Land Raider tank model is 17 cm long but conceptually 10.3 m long. This scale does not correspond to the range of firearms: on the table, a boltgun has a range of 24 inches, which corresponds to only 120 feet (36.6 m) at 1:60 scale. A model of a Primaris Space Marine is about 4.5 cm in height.
Playing field.
"Warhammer 40,000" is meant to be played on a table. The official rulebook recommends a table width of . In contrast to board games, "Warhammer 40,000" does not have a fixed playing field. Players are expected to construct their own custom-made playing field using modular terrain models. Games Workshop sells a variety of proprietary terrain models, but players often use generic or homemade ones too. Unlike certain other miniature wargames, such as "BattleTech", "Warhammer 40,000" does not use a grid system. Players must use measuring tape (and templates in other editions) to measure distances. Distances are measured in inches.
Assembling armies.
An "army" in this context refers to all the model warriors that a player will play with in a match. In "Warhammer 40,000", players are not restricted to playing with a fixed and symmetrical combination of warriors as in chess. They get to choose which warriors and armaments they will fight with from a list presented in the rulebooks. The players' must decide and agree on what models they will play with before the match starts, and once the match is underway they cannot add any new units to their armies. 
The players may choose the models they will play with, subject to some limitations. The first limitation is narrative. "Warhammer 40,000" has a well-developed fictional setting and the match must be designed to fit it. Firstly, players may use only model warriors that were specifically designed by Games Workshop for use in "Warhammer 40,000". Using wargaming models made for other wargames will cause confusion and spoil the aesthetic. For instance, a player cannot use a model of a Greek hoplite in a "Warhammer 40,000" match because the rulebooks provide no rules or stats for Greek hoplites, and in the fictional setting Greek hoplites do not exist.
The composition of the armies must fit the rivalries and alliances depicted in the setting. All model warriors listed in the rulebooks are classified into "factions", such as "Imperium", "Chaos", "Tau Empire", etc. In a matched game, a player may only use warrior models in their army that are all loyal to a common faction. Thus, a player cannot, for example, use a mixture of Aeldari and Necron model warriors in their army. That would not make sense, for in the game's fictional setting, Aeldari and Necrons are mortal enemies and would never fight alongside each other. Likewise, a player cannot (or at least should not) use models from the same faction as their opponent's. It would not make sense for Aeldari to fight fellow Aeldari unless the players decide on an unusual narrative contrivance. Besides, it would also make the match confusing as the models from either side would resemble each other too much. In a computer game, the game engine might automatically colour-code the virtual warriors to prevent the players confusing each other's warriors, but this is not possible with the painted physical models of "Warhammer 40,000", so the players must use different factions.
The second limitation is the rules' constraints on what combination of warriors and armaments a player can have in the army. These constraints are designed to ensure that both armies are "balanced", i.e. neither has an unfair advantage over the other. Firstly, the players must agree as to what "points limit" they will play at, which roughly determines how big and powerful their respective armies will be. Each model and weapon has a "point value" which roughly corresponds to how powerful the model is; for example, a Tactical Space Marine is valued at 13 points, whereas a Land Raider tank is valued at 239 points. The sum of the point values of a player's models must not exceed the agreed limit. If the point values of the players' respective armies both add up to the limit, they are generally assumed to be balanced. 1,000 to 3,000 points are common points limits. In the most recent edition of the game, power levels are assigned to each model, which can be used to simplify or vary the process of creating an army list.
The third limitation is the money and effort it would take to purchase, assemble, and paint the models in the army, and then play with them. In a computer strategy game, players can have the computer conjure as many virtual units as they please, but "Warhammer 40,000" is played with physical models that cost money and must be assembled and painted. A player might spend weeks assembling and painting models before the army is ready for play. A large army is commensurately more expensive and time-consuming to prepare, and will also slow down the pace of the match as each player has that many more models to move around and think about.
Moving and attacking.
At the start of a game, each player places their models in starting zones at opposite ends of the playing field.
At the start of their turn, a player moves each model in their army by hand across the field. A model can be moved no farther than its listed "Move characteristic". For instance, a model of a Space Marine can be moved no farther than six inches per turn. If a model cannot fly, it must go around obstacles such as walls and trees.
Models are grouped into "units". They move, attack, and suffer damage as a unit. All models in a unit must stay close to each other. Each model in a unit must finish a turn within two inches of another model from the unit. If there are more than five models in a unit, each model must be within two inches of two other models.
After moving, each unit can attack any enemy unit within range and line-of-fire of whatever weapons and psychic powers its models have. For instance, a unit of Space Marines armed with "boltguns" can shoot any enemy unit within 24 inches. The attacking player rolls dice to determine how much imaginary damage their models inflicted on the enemy unit. The attacking player cannot target individual models within an enemy unit; if an enemy unit suffers damage, the enemy player decides which models in the unit suffered injury. Damage is measured in points, and if a model suffers more points of damage than its "Wound characteristic" permits, it dies. Dead models are removed from the playing field.
Most of the races in the game have units with psychic powers. Psyker units can cause unusual effects, such as rendering allied units invulnerable or teleporting units across the battlefield. Any psyker unit can nullify the powers of an enemy psyker by making a Deny the Witch roll.
Victory conditions.
Victory depends on what kind of "mission" the players choose for their game. It might involve exterminating the enemy, or holding a location on the field for a certain length of time, or retaining possession of a holy relic for a certain length of time.
Setting.
Most "Warhammer 40,000" fiction is set around the turn of the 42nd millennium (about 39,000 years in the future). Although "Warhammer 40,000" is mostly a science-fiction setting, it adapts a number of tropes from fantasy fiction, such as magic, supernatural beings, daemonic possession, and races such as Orks and Elves; "psykers" fill the role of wizards in the setting. The setting of this game shares many tropes with "Warhammer Fantasy" (a similar wargame from Games Workshop), but their respective settings are not connected. "Warhammer 40,000" and "Warhammer Fantasy" inherit many of their fantasy tropes from "Dungeons and Dragons". Games Workshop used to make miniature models for use in "Dungeons and Dragons", and "Warhammer Fantasy" was originally meant to encourage customers to buy more of their miniature models.
The setting of "Warhammer 40,000" is violent and pessimistic. It depicts a future where human scientific and social progress have ceased, and human civilisation is close to collapse due to war with hostile alien races and occult forces. It is a setting where the supernatural exists, is powerful, and is usually untrustworthy if not outright malevolent. There are no benevolent gods or spirits in the cosmos, only daemons and evil gods, and the cults dedicated to them are growing. In the long run, the Imperium of Man cannot hope to defeat its enemies, so the heroes of the Imperium are not fighting for a brighter future but "raging against the dying of the light". The tone of the setting has led to a subgenre of science fiction called "grimdark", which is particularly amoral, dystopian or violent.
As the setting is based on a wargame, the spin-off novels and comic books are mostly war dramas with protagonists who are usually warriors of some sort, the most popular being the Space Marines. A key theme of the setting is that the Imperium is in a state of total war. Many planets in the Imperium of Man are either warzones or heavily burdened by wartime taxation, and civil liberties are heavily curtailed in the name of security.
The setting is, by the admission of its own writers, deliberately absurd and hyperbolic. This applies to the scale. The Imperium of Man has lasted 10,000 years, controls roughly a million planets, and has a population that likely numbers in the trillions. The armaments and tactics seen in the setting are equally nonsensical, such as the heavy usage of melee weaponry, war machines that tower hundreds of feet above the ground (and thus make easy targets for artillery), and magic-users who place curses on their foes.
The source of magic in the setting is a parallel universe of supernatural energy known as "the Warp". All living creatures with souls are tied to the Warp, but certain individuals called "psykers" have an especially strong link and can manipulate the Warp's energy to work magic. Psykers are generally feared and mistrusted by humans. Psykers may possess many dangerous abilities such as mind control, clairvoyance, and pyrokinesis. Moreover, the Warp is full of predatory supernatural creatures that may use a psyker's link to the Warp as a conduit by which to invade realspace. Despite their associated suspicion and danger, psykers perform critical services for humanity: their powers permit faster-than-light communication, which is impossible under the "normal" laws of physics, and on the battlefield they counter the powers of enemy psykers. A key theme of the setting is that for all the problems that psykers pose, human civilisation cannot do without them. For this reason, psykers must be trained to control their abilities and resist Warp predators. Those who fail or reject this training are executed for the safety of all. Those who pass their training are pressed into life-long servitude to the state and are closely monitored for misconduct and spiritual corruption.
Influences.
Rick Priestley cites J. R. R. Tolkien, H. P. Lovecraft, "Dune", "Paradise Lost", and "2000 AD" as major influences on the setting. 
The Chaos Gods were added to the setting by Bryan Ansell and developed further by Priestley. Priestley felt that "Warhammer"s concept of Chaos, as detailed by Ansell in the supplement "Realms of Chaos", was too simplistic and too similar to the works of Michael Moorcock, so he developed it further, taking inspiration from "Paradise Lost". The story of the Emperor's favored sons succumbing to the temptations of Chaos deliberately parallels the fall of Satan in "Paradise Lost". The religious themes are primarily inspired by the early history of Christianity. Daemons in WH40K are manifestations of human dreams and emotion, given physical form and sentience by the Warp — this idea comes from the 1956 movie "Forbidden Planet".
The Emperor of Man was inspired by various fictional god-kings, such as Leto Atreides II from the novel "God Emperor of Dune" by Frank Herbert, and King Huon from the "Runestaff" novels by Michael Moorcock. The Emperor's suffering on the Golden Throne for the sake of humanity mirrors the sacrifice of Jesus Christ.
Factions.
The myriad models available for play in "Warhammer 40,000" are divided into "factions". Under normal circumstances, a player can only use units from the same faction in their army. For instance, a player's army cannot include both Ork and Aeldari models because Orks and Aeldari are enemies in the setting.
The Imperium of Man.
The Imperium of Man is an authoritarian human empire that comprises about 1 million worlds, and has existed for over 10,000 years. The Imperium is a totalitarian theocracy and its chief deity and de jure head of state is the Emperor of Mankind. The Emperor is an extremely powerful psyker who is worshipped as a god. Anyone who does not revere the Emperor properly is liable to be persecuted for heresy. The Emperor founded the Imperium and is still its nominal ruler, but roughly two centuries after founding the Imperium he was mortally wounded in battle and has been on life support in an unresponsive state ever since. Despite his condition, he can still generate a psychic beacon by which starships can navigate the Warp, making him the lynchpin of the Imperium's infrastructure. Although the Imperium has highly advanced technology, the Imperium has long ceased practicing science and its technologies have not improved for thousands of years. Imperial citizens are taught to obey authority without question, to worship the Emperor, to hate and fear aliens, and to be incurious about anything that does not concern their duties.
Most "Warhammer 40,000" fiction has humans of the Imperium as the protagonists, with other races being antagonists or supporting characters. The most popular sub-faction of the Imperium are the Space Marines. Of all the factions, the Imperium has the largest catalogue of models spread across numerous subfactions, which gives Imperium players the flexibility to design their army for any style of play.
Chaos.
Chaos represents the myriad worshippers and servants of the Chaos Gods, malevolent and depraved entities formed from the most base thoughts and emotions of mortals, that dwell in an alternate reality of pure psychic energy known as the Warp. Those exposed to the corruptive influence of the Chaos are twisted in both mind and body, encouraged to perform acts of devotion and servitude to the Gods, who in turn reward them with "gifts" of physical mutations, psychic power, ancient artifacts, and marks of the Gods' favor in their efforts to bring about the end of the Imperium of Man. As a faction, the forces of Chaos are malevolent and insane in nature, adopting the aesthetics of body horror and cosmic horror in the design of their models and story details. Chaos is among the oldest and most notable enemies of the Imperium, and the ongoing conflict between those still loyal to the God-Emperor and those who have "fallen" to the Chaos Gods acts as a persistent theme in the setting of "Warhammer 40,000". 
Like the Imperium, the forces of Chaos have access to a large variety of models spread across multiple sub-factions, allowing a Chaos army a broad spectrum of gameplay styles, with a persistent focus on designating individual units with "marks" of the different Chaos Gods, granting them special qualities. Notable sub-factions include the Chaos Space Marines, traitorous Space Marines aligned with the Chaos Gods, and Chaos Daemons, entities of pure psychic energy that act as extensions of the Chaos Gods' will within the material realm.
Necrons.
The Necron faction was introduced to the WH40K universe more recently, in 1998. The Necrons are an ancient race of skeleton-like androids. Millions of years ago, they were flesh-and-blood beings. Seeking to extend their short lifespans, they transferred their minds into mechanical bodies made up of a self-healing material called necrodermis to achieve immortality. However, the transference process was flawed, and all but the most high-ranking Necrons became mindless automatons. They are waking up from millions of years of hibernation in underground vaults on planets across the galaxy, and seek to rebuild their old empire.
Necron infantry have strong ranged firepower, tough armour, and slow movement. Necron units have the ability to rapidly regenerate wounds or "reanimate" slain models after a successful attack from the enemy against them has been completed. All Necron models have a Leadership score of 10 (the maximum), so Necrons rarely suffer from morale failure. Necrons do not have any psykers, which leaves them with fewer defensive options against enemy psykers. The Necrons possess "C'tan shards" which function much like psykers, but since these are not actual psykers, they cannot make Deny the Witch rolls, nor can their powers be countered by enemy Deny the Witch rolls.
Aeldari.
The Aeldari are based on High Elves of fantasy fiction. They are a haughty species who view humans and other non-Aeldari as vermin. Aeldari have very long lifespans and all of them have some psychic ability. The Aeldari travel the galaxy via a network of magical tunnels called "the Webway". In the distant past, the Aeldari ruled an empire that dominated much of the galaxy, but it was destroyed in a magical cataclysm along with most of the population. The surviving Aeldari are divided into the ascetic inhabitants of massive starships called Craftworlds, and the Drukhari (also known as "Dark Eldar"), a race of sadistic space pirates who inhabit a city hidden within the Webway. Additionally, new factions have arisen. These include the Harlequins, followers of the Laughing God Cegorach, and the Ynnari, followers of the death god Ynnead. Although it has been 10,000 years since their empire's fall, the Aeldari have never recovered, due to their low fertility and attacks by other races.
Craftworld Aeldari infantry tend to be highly specialised and relatively frail, often described as "glass cannons." Because of their lack of staying power and flexibility, Aeldari armies can suffer severe losses after a bad tactical decision or even unlucky dice rolls, while successful gameplay can involve outnumbered Aeldari units which outmanoeuvre the opponent and kill entire squads before they have a chance to retaliate. Aeldari vehicles, unlike their infantry counterparts, are very tough and hard to kill because of many evasive and shielding benefits. With the exception of walkers, all Aeldari vehicles are skimmers which allow them to move "freely" across the board and, with upgrades, at speeds only matched by the Dark Aeldari and the Tau armies.
Dark Aeldari are similar to Craftworld Aeldari in that they are typically frail but move quickly and deal a high amount of damage relative to their points costs.
Orks.
The Orks are green-skinned aliens based on the traditional orcs of high fantasy fiction. Orks are a comical species, possessing crude personalities, wielding ramshackle weaponry, and speaking with Cockney accents. Their culture revolves around war for the sake of it. Unlike other races which generally only go to war when it is in their interests, the Orks recklessly start unnecessary conflicts and will flock to warzones in the hope of finding a good fight, because Orks do not fear death and combat is the only thing that gives them emotional fulfilment. Ork technology consists of dashed together scrap that by all logic should be dangerously unreliable or not function at all, yet Orks emit a gestalt psychic field that subtly bends reality and allows their gear to operate effectively due to the Orks' simple belief that it should.
In the tabletop game, Ork infantry units are slow-moving and relatively tough. The Orks are oriented towards melee combat; they can re-roll failed charge rolls. Infantry units are cheap (by point cost), so a favourite strategy is "the Green Tide": the player fields as many Orks as they can and simply marches them across the playing field to swarm their opponent. Orks do have a number of specialised units who can use psychic powers and attack vehicles (among other things), but typically Ork warfare is about brute force and attrition. Ork gameplay is seen as fairly forgiving of tactical errors and bad die rolls.
Tyranids.
The Tyranids are a mysterious alien race from another galaxy. They migrate from planet to planet, devouring all life in their path. Tyranids are linked by a psychic hive mind and individual Tyranids become feral when separated from it. Tyranid "technology" is entirely biological, ships and weapons being purpose-bred living creatures.
Tyranids have a preference for melee combat. Their infantry units tend to be fast and hard-hitting but frail. They have low point costs, meaning Tyranid armies in the game are relatively large (many cheap weak units, as opposed to armies with few expensive powerful units such as the Space Marines). Tyranids also have the most powerful counter-measures against enemies with psychic powers: many Tyranid units possess a trait called "Shadow in the Warp", which makes it harder for nearby enemy psykers to use their psychic powers.
There is a sub-species of the Tyranid race called "Genestealers". Genestealers are visually inspired by the monster from the movie "Alien", and also take inspiration from H. P. Lovecraft's short story "The Shadow Over Innsmouth". When a human is infected by a Genestealer, they are psychically enslaved and will sire children who are human-genestealer hybrids. These hybrids will form a secret society known as a Genestealer Cult within their host human society, steadily expanding their numbers and political influence. When a Tyranid fleet approaches their planet, they will launch an uprising to weaken the planet's defences so that the Tyranids may more easily conquer it and consume its life.
In earlier editions of the game, Genestealer Cults could only be used as auxiliaries to a regular Tyranid army, but since 8th edition, they can be played as a separate army. Although there is a dedicated line of Genestealer Cult models, a player can also use units from the Imperial Guard (a sub-faction of the Imperium) in their Genestealer Cult army. This is an exception to the common-faction rule and is based on the logic that these "human" units are actually Genestealer hybrids who look perfectly human. Like other Tyranids, Genestealers are hard-hitting but fragile. All Genestealer Cult infantry and bikers have a trait called "Cult Ambush" that allows them to be set up off table and later be set up on the table, instead of being set up in the designated starting zones at the start of the game (similar to the Space Marines' "Deep Strike" ability).
T'au.
The T'au are a race of blue-skinned aliens inhabiting a relatively small but growing empire located on the fringes of the Imperium of Man. The T'au Empire is the only playable faction in the setting that integrates alien species into their society. They seek to subjugate all other races under an ideology they call "the Greater Good" or "Tau'va". Some human worlds have willingly defected from the Imperium to serve the T'au Empire. Although humans are effectively second-class citizens in T'au society despite being equal in principle, they tend to have a better quality of life than Imperial citizens because the T'au still practice science and encourage the spread of technical knowledge (political ideas are another matter). The T'au are divided into five endogamous castes: the Ethereals, who rule; the Fire Caste, who fight on the ground; the Air Caste, who operate starships; the Water Caste, who are merchants and diplomats; and the Earth Caste, who are scientists, engineers, and labourers.
The T'au are oriented towards ranged combat and generally die quickly in close quarters. They have some of the most powerful firearms in the game in terms of both range and stopping power. For instance, their pulse rifle surpasses the firepower of the Space Marine boltgun, and the railgun on their main battle tank (the Hammerhead) is more powerful than its Imperium counterparts. They heavily use the Overwatch special rule, which allows them to shoot back at their enemies when charged with relatively devastating power. The T'au do not have any psykers nor units that specialise in countering psykers, which makes them somewhat more vulnerable to psychic attacks. Most T'au vehicles are classified as flyers or skimmers, meaning they can move swiftly over difficult terrain. The T'au also incorporate alien auxiliaries into their army: the Kroot provide melee support and the insectoid Vespids serve as jump infantry.
History.
In 1982, Rick Priestley joined Citadel Miniatures, a subsidiary of Games Workshop that produced miniature figurines for use in "Dungeons and Dragons". Bryan Ansell (the manager of Citadel) asked Priestley to develop a medieval-fantasy miniature wargame that would be given away for free to customers so as to encourage them to buy more miniatures. "Dungeons and Dragons" did not require players to use miniature figurines, and even when players used them they rarely needed more than a handful. The result was "Warhammer Fantasy Battle", which was released in 1983 to great success. 
"Warhammer Fantasy" was principally a medieval fantasy game in the vein of "Dungeons and Dragons", but Priestley and his fellows designers added a smattering of optional science fiction elements, namely in the form of advanced technological artefacts (e.g. laser weapons) left behind by a long-gone race of spacefarers. "Warhammer 40,000" was an evolution of this taken to the opposite extreme (i.e. mostly science-fiction but with some fantasy elements).
Since before working for Games Workshop, Priestley had been developing a spaceship combat tabletop wargame called "Rogue Trader", which mixed science fiction with classic fantasy elements. Priestley integrated many elements of the lore of "Rogue Trader" into "Warhammer 40,000", chiefly those concerning space travel, but he discarded the ship combat rules for lack of space in the book.
Games Workshop planned to sell conversion kits by which players could modify their "Warhammer Fantasy" models to wield futuristic weaponry such as laser weapons, but eventually Games Workshop decided to create a dedicated line of models for "Warhammer 40,000".
Initially, Priestley's new game was simply to be titled "Rogue Trader", but shortly before release Games Workshop signed a contract with 2000 AD to develop a board game based on their comic book "Rogue Trooper". So as not to confuse customers, Games Workshop renamed Priestley's game "Warhammer 40,000: Rogue Trader" and marketed it as a spin-off of "Warhammer Fantasy Battle" (which in many ways, it was).
"Warhammer 40,000: Rogue Trader" received its first full preview in "White Dwarf" #93 (September 1987).
"" was released in October 1987. It was a success and became Games Workshop's most important product. In the January 1988 edition of "Dragon" (issue 129), Ken Rolston raved about this game, calling it "colossal, stupendous, and spectacular... This is the first science-fiction/fantasy to make my blood boil."
First edition ("Warhammer 40,000: Rogue Trader") (1987).
The first edition of the game was titled "", and its rules are based on "Warhammer Fantasy Battle". "Rogue Trader" had been the game's working title during development, and shortly before release, Games Workshop decided to add "Warhammer 40,000" to the title so as to brand it as a sci-fi spin-off of "Warhammer Fantasy". The "Rogue Trader" subtitle was dropped in subsequent editions. It was published in 1987. Game designer Rick Priestley created the original rules set (based on the contemporary second edition of "Warhammer Fantasy Battle") alongside the "Warhammer 40,000" gameworld. The gameplay of "Rogue Trader" was heavily oriented toward role-playing rather than strict wargaming. This original version came as a very detailed, though rather jumbled, rulebook, which made it most suitable for fighting small skirmishes. Much of the composition of the units was determined randomly, by rolling dice. A few elements of the setting (bolters, lasguns, frag grenades, Terminator armour) can be seen in a set of earlier wargaming rules called "Laserburn" (produced by the now defunct company Tabletop Games) written by Bryan Ansell. These rules were later expanded by both Ansell and Richard Halliwell (both of whom ended up working for Games Workshop), although the rules were not a precursor to "Rogue Trader".
In addition, supplemental material was continually published in "White Dwarf" magazine, which provided rules for new units and models. Eventually, "White Dwarf" provided proper "army lists" that could be used to create larger and more coherent forces than were possible in the main rulebook. These articles were from time to time released in expansion books along with new rules, background materials and illustrations. All in all ten books were released for the original edition of "Warhammer 40,000": "Chapter Approved – Book of the Astronomican", "Compendium", "Warhammer 40,000 Compilation", "Waaagh – Orks", two "Realm of Chaos" ("Slaves to Darkness" and "The Lost and the Damned"), "'Ere we Go", "Freebooterz", "Battle Manual", and "Vehicle Manual". The "Battle Manual" changed and codified the combat rules and provided updated stats for most of the weapons in the game. The "Vehicle Manual" contained a new system for vehicle management on the tabletop which was intended to supersede the clunky rules given in the base hardback manual and in the red softback compendium, it had an inventive target location system which used acetate crosshairs to simulate weapon hits on the vehicle silhouettes with different armour values for different locations (such as tracks, engine compartment, ammo store, and so on). "Waaagh – Orks" was an introductory manual to Orkish culture and physiology. It contained no rules, but background material. Other Ork-themed books instead were replete with army lists for major Ork clans and also for greenskin pirate and mercenary outfits. The "Realm of Chaos" books were hefty hardback tomes, which included rules for Chaos in "Warhammer 40,000", "Warhammer Fantasy Roleplay" and "Warhammer Fantasy Battle" (3rd edition).
Second edition (1993).
The second edition of "Warhammer 40,000" was published in late 1993. This new course for the game was forged under the direction of editor Andy Chambers. 
The second edition came in a boxed set that included Space Marine (two 10-man Tactical Squads, each with a Sergeant with chainsword, missile launcher, and flamer) and Ork (20 Orks, 40 Gretchin) miniatures, scenery, dice, and the main rules. The box artwork and studio army depicted the Blood Angels Chapter.
An expansion box set titled "Dark Millennium" was later released, which included rules for psychic powers. Another trait of the game was the attention given to "special characters" representing specific individuals from the background, who had access to equipment and abilities beyond those of others; the earlier edition only had three generic "heroic" profiles for each army: "champion", "minor hero" and "major hero".
The second edition introduced major revisions to the lore and would go on to define the general character of the lore up until the 8th edition. The Adeptus Mechanicus' prohibition on artificial intelligence was added, stemming from an ancient cataclysmic war between humans and sentient machines; this was inspired by the "Dune" novels.
Third edition (1998).
The third edition of the game was released in 1998 and, like the second edition, concentrated on streamlining the rules for larger battles. Third-edition rules were notably simpler. The rulebook was available alone, or as a boxed set with miniatures of Space Marines (one 10-man Tactical Squads with a Sergeant, missile launcher, and flamer, and the redesigned Space Marine Landspeeder with a Heavy Bolter) and the newly introduced Dark Eldar (now called "Drukhari") (20 Kabalite Warriors). The system of army codexes continued in third edition. The box artwork and studio army depicted the Black Templars Space Marine Chapter.
Towards the end of the third edition, four new army codexes were introduced: the xeno (that is, alien) races of the Necron and the Tau and two armies of the Inquisition: the Ordo Malleus (called Daemonhunters), and the Ordo Hereticus (called Witchhunters); elements of the latter two armies had appeared before in supplementary material (such as "Realm of Chaos" and "Codex: Sisters of Battle"). At the end of the third edition, these armies were re-released with all-new artwork and army lists. The release of the Tau coincided with a rise in popularity for the game in the United States.
Fourth edition (2004).
The fourth edition of "Warhammer 40,000" was released in 2004. This edition did not feature as many major changes as prior editions, and was "backwards compatible" with each army's third-edition codex. The fourth edition was released in three forms: the first was a standalone hardcover version, with additional information on painting, scenery building, and background information about the "Warhammer 40,000" universe. The second was a boxed set, called "Battle for Macragge", which included a compact softcover version of the rules, scenery, dice, templates, and Space Marines and Tyranid miniatures. The third was a limited collector's edition. "Battle for Macragge" was a 'game in a box', targeted primarily at beginners. "Battle for Macragge" was based on the Tyranid invasion of the Ultramarines' homeworld, Macragge. An expansion to this was released called "The Battle Rages On!", which featured new scenarios and units, like the "Tyranid Warrior".
Fifth edition (2008).
The fifth edition of Warhammer 40,000 was released on July 12, 2008. While there are some differences between the fourth and fifth editions, the general rule set shares numerous similarities. Codex books designed prior to the fifth edition are still compatible with only some changes to how those armies function. The replacement for the previous edition's "Battle for Macragge" starter set is called "Assault on Black Reach", which features a pocket-sized rulebook (containing the full ruleset but omitting the background and hobby sections of the full-sized rulebook), and starter armies for the Space Marines (1 Space Marine Captain, one 10-man Tactical Squad, one 5-man Terminator Squad, one Space Marine Dreadnought) and Ork (one Ork Warboss, 20 Ork Boyz, 5 Ork Nobz, 3 Ork Deffkoptas).
New additions to the rules include the ability for infantry models to "Go to Ground" when under fire, providing additional protection at the cost of mobility and shooting as they dive for cover. Actual line of sight is needed to fire at enemy models. Also introduced is the ability to run, whereby units may forgo shooting to cover more ground. In addition, cover has been changed so that it is now easier for a unit to get a cover save. Damage to vehicles has been simplified and significantly reduced, and tanks may now ram other vehicles. Some of these rules are modelled after rules that existed in the Second Edition, but were removed in the Third. Likewise, 5th edition codexes have seen a return of many units previously cut out in the previous edition for having unwieldy rules. These units have largely been brought back with most of their old rules streamlined for the new edition. Fifth edition releases focused largely on Space Marine forces, including the abolishment of the Daemonhunters in favour of an army composed of Grey Knights, a special chapter of Space Marines, which, in previous editions, had provided the elite choices of the Daemonhunter's army list. Another major change was the shift from metal figures to resin kits.
Sixth edition (2012).
Sixth edition was released on June 23, 2012. Changes to this edition include the adoption of an optional Psychic Power card system similar to that of the game's sister product "Warhammer Fantasy Battle" as well as the inclusion of full rules for flying vehicles and monsters and a major reworking of the manner in which damage is resolved against vehicles. It also includes expanded rules for greater interaction with scenery and more dynamic close-combat. In addition to updating existing rules and adding new ones, 6th Edition introduced several other large changes: the Alliance system, in which players can bring units from other armies to work with their own, with varying levels of trust; the choice to take one fortification as part of your force; and Warlord traits, which will allow a player's Commander to gain a categorically randomised trait that can aid their forces in different situations. Replacing the "Assault on Black Reach" box set is the "Dark Vengeance" box set which includes Dark Angels and Chaos Space Marine models. Some of the early release box sets of Dark Vengeance contained a limited edition Interrogator-Chaplain for the Dark Angels. 
The Imperial Knights (Codex: Imperial Knights) were a new addition to the Imperium of Man faction. Previously found in Epic large scale battles, particularly the Titan Legions (2nd Edition) boxed set, the Imperial Knights are walkers that are smaller than proper Imperial Titans but nonetheless tower over all other Warhammer 40,000 vehicles and troops.
Seventh edition (2014).
Announced in "White Dwarf" issue 15, pre-orders for May 17 and release date of May 24, 2014.
The 7th edition saw several major changes to the game, including a dedicated Psychic Phase, as well as the way Psychic powers worked overall, and changeable mid-game Tactical Objectives. Tactical Objectives would give the players alternate ways to score Victory Points, and thus win games. These objectives could change at different points during the game.
As well as these additions, the 7th edition provided a new way to organise Army lists. Players could play as either Battle-Forged, making a list in the same way as 6th edition, or Unbound, which allowed the player to use any models they desired, disregarding the Force Organisation Chart. Bonuses are given to Battle-Forged armies. Additionally, Lord of War units, which are powerful units previously only allowed in large-scale ("Apocalypse") games, are now included in the standard rulebook, and are a normal part of the Force Organisation Chart.
Eighth edition (2017).
Announced on April 22, 2017, pre-orders for June 3 and release date of June 17, 2017.
The 8th edition was a major revision intended to make it easier for new players to enter the hobby. In this respect, the game introduced the Three Ways to Play concept: Open, Matched, and Narrative. The core ruleset was simplified down to 14 pages, and was available as a free PDF booklet on the Games Workshop website. The more complex rules are retained in the updated hardcover Rulebook. The narrative of the setting has also been updated: an enlarged Eye of Terror has split the galaxy in half, while the Primarch Roboute Guilliman returns to lead the Imperium as its Lord Commander, beginning with reclaiming devastated worlds through the Indomitus Crusade.
The 8th Edition introduced a new box set called "Dark Imperium", which featured the next-generation Primaris Space Marines which are available as reinforcements to existing Space Marine Chapters, as well as introducing new characters and rules to the Death Guard Chaos Space Marines.
Ninth edition (2020).
The ninth edition was released in July 2020. With it came a redesigned logo (the first in 22 years). The 9th edition is not a total overhaul of the 8th edition's rules. Codexes, supplements and the rules from the Psychic Awakening series made for 8th edition are compatible with 9th.
9th edition also introduced four new box sets: Indomitus, a limited release set that came out at the start of 9th edition, and the Recruit, Elite and Command editions. The four boxes feature revised designs and new units for the Necrons, and new units for the Primaris Space Marines.
Supplements and expansions.
There are many variations to the rules and army lists that are available for use, typically with an opponent's consent. These rules are found in the Games Workshop publication "White Dwarf", on the Games Workshop website, or in the Forge World "Imperial Armour" publications.
The rules of "Warhammer 40,000" are designed for games between 500 and 3000 points, with the limits of a compositional framework called the Force Organisation Chart making games with larger point values difficult to play. In response to player comments, the "Apocalypse" rules expansion was introduced to allow 3000+ point games to be played. Players might field an entire 1000-man Chapter of Space Marines rather than the smaller detachment of around 30–40 typically employed in a standard game. Apocalypse also contains rules for using larger war machines such as Titans. 
"Cities of Death" (the revamp of "Codex Battlezone: Cityfight") introduces rules for urban warfare and guerrilla warfare, and so-called "stratagems", including traps and fortifications. It also has sections on modelling city terrain and provides examples of armies and army lists modeled around the theme of urban combat. This work was updated to 7th Edition with the release of Shield of Baal: Leviathan.
"Planetstrike", released 2009, sets rules allowing players to represent the early stages of a planetary invasion. It introduces new game dynamics, such as dividing the players into an attacker and a defender, each having various tactical benefits tailored to their role; for example, the attacker may deep strike all infantry, jump infantry and monstrous creatures onto the battlefield, while the defender may set up all the terrain on the battlefield.
"Planetary Empires", released August 2009, allows players to coordinate full-scale campaigns containing multiple battles, each using standard rules or approved supplements such as "Planetstrike", "Cities of Death" or "Apocalypse". Progress through the campaign is tracked using hexagonal tiles to represent the current control of territories within the campaign. The structure is similar to "Warhammer Fantasy's Mighty Empires".
"Battle Missions", released March 2010, this expansion contains a series of 'missions' with specific objectives, each 'race' has three specific missions which can be played, these missions are determined by a dice roll and are usually chosen from the two armies being used. They still use the standard rules from the "Warhammer 40,000" rule book.
"Spearhead", released May 2010, allows players to play games with a greater emphasis on armoured and mechanised forces. The most notable change to the game is the inclusion of special "Spearhead Formations;" and greater flexibility in force organisation. "Spearhead Formations" represent a new and altogether optional addition to the force organisation system standard to "Warhammer 40,000". Players now have the ability to use all, part or none of the standard force organisation. "Spearhead" also includes new deployment options and game scenarios. This expansion is being released jointly through the Games Workshop website, as a free download, and through the company's monthly hobby magazine "White Dwarf".
"Death from the Skies", released February 2013, contains rules for playing games with an emphasis on aircraft. There are specific rules for each race's aircraft, as well as playable missions. A notable inclusion in this release is "warlord traits" for each race that deal specifically with aircraft. This supplement still uses the same rules as the "Warhammer 40,000" rulebook. Got updated to 7th Edition with "Shield of Baal: Leviathan".
"Stronghold Assault", released in December 2013, is a 48-page expansion that contains more rules for fortifications in the game, as well as rules for more fortifications that listed in the main 6th Edition Rulebook.
"Escalation", released December 2013, contains rules for playing games with super heavy vehicles, normally restricted to Apocalypse events, in normal events.
Spin-off games, novels, and other media.
Games Workshop has expanded the "Warhammer 40,000" universe over the years to include several spin-off games and fictional works. This expansion began in 1987, when Games Workshop asked Scott Rohan to write the first series of "literary tie-ins". This eventually led to the creation of Black Library, the publishing arm of Games Workshop, in 1997. The books published relate centrally to the backstory in the "Warhammer" universe. Black Library also publishes "Warhammer 40,000" graphic novels.
Several popular miniature game spin-offs were created, including "Space Crusade", "Space Hulk", "Kill Team", "Battlefleet Gothic", "Epic 40,000", "Inquisitor", "Gorkamorka", "Necromunda" and "Assassinorum: Execution Force". A collectible card game, "Dark Millennium", was launched in October 2005 by Games Workshop subsidiary, Sabertooth Games. The story behind the card game begins at the end of the Horus Heresy arc in the game storyline and contains four factions: the Imperium, Orks, Aeldari and Chaos.
Music.
The album "Realms of Chaos: Slaves to Darkness" by British death metal band Bolt Thrower features lyrics as well as artwork based on the "Warhammer" and "Warhammer 40,000" brands, with the album's title design being identical to that of the eponymous Games Workshop books. 
In the early 1990s Games Workshop set up their own label, "Warhammer Records". The band D-Rok were signed to this label; their only album "Oblivion" featured songs based on "Warhammer 40,000".
Novels.
Following the 1987 initial release of Games Workshop's "Warhammer 40,000" wargame the company began publishing background literature that expands previous material, adds new material, and describes the universe, its characters, and its events in detail. Since 1997 the bulk of background literature has been published by the affiliated imprint Black Library.
The increasing number of fiction works by an expanding list of authors is published in several formats and media, including audio, digital and print. Most of the works, which include full-length novels, novellas, short stories, graphic novels, and audio dramas, are parts of named book series. In 2018, a line of novels for readers aged 8 to 12 was announced, which led to some confusion among fans given the ultra-violent and grimdark nature of the setting.
Video games.
Games Workshop first licensed Electronic Arts to produce "Warhammer 40,000" video-games, and EA published two games based on Space Hulk in 1993 and 1995. Games Workshop then passed the license to Strategic Simulations, which published three games in the late 1990s. After Strategic Simulations went defunct in 1994, Games Workshop then gave the license to THQ, and between 2003 and 2011 THQ published 13 games, which include the "Dawn of War" series. After 2011, Games Workshop changed its licensing strategy: instead of an exclusive license to a single publisher, it broadly licenses a variety of publishers.
Board games and role-playing games.
Games Workshop have produced a number of standalone "boxed games" set within the "Warhammer 40,000" setting; they have licensed the intellectual property to other game companies such as Fantasy Flight Games. The 
Games Workshop-produced boxed games tend to be sold under the aegis of the "Specialist Games" division. Titles include:
Although there were plans to create a full-fledged "Warhammer 40,000" "pen and paper" role-playing game from the beginning, these did not come to fruition for many years, until an official "Warhammer 40,000" role-playing game was published only in 2008, with the release of "Dark Heresy" by Black Industries, a Games Workshop subsidiary. This system was later licensed to Fantasy Flight Games for continued support and expansion.
Formerly Games Workshop licensed a number of "Warhammer 40K" themed products to Fantasy Flight Games. They specialise in board, card and role-playing games. Included in the licensed product were:
Film.
On December 13, 2010, "Ultramarines: A Warhammer 40,000 Movie" was released directly to DVD. It is a CGI science fiction film, based around the Ultramarines Chapter of Space Marines. The screenplay was written by Dan Abnett, a Games Workshop Black Library author. The film was produced by Codex Pictures, a UK-based company, under license from Games Workshop. It utilised animated facial capture technology from Image Metrics.
TV.
On July 17, 2019, Games Workshop and Big Light Productions announced the development of a live-action TV series based on the character Gregor Eisenhorn, who is an Imperium Inquisitor. Frank Spotnitz will be the showrunner for the series. The series is expected to be based on the novels written by Dan Abnett.
Awards.
"Warhammer 40,000" 2nd Edition won the 1993 Origins Award for "Best Miniatures Rules".
In 2003, "Warhammer 40,000" was inducted into the Origins Hall of Fame.
"Warhammer 40,000" 8th Edition won the 2017 Origins Awards for Best Miniatures Game and Fan Favorite Miniatures Game.