Warhammer 40,000 - Setting: The Warhammer 40,000 universe is most readily characterized as a Gothic science fantasy setting.The central and most popular elements of the Warhammer 40,000 universe are the Space Marines, anachronistic combinations of science fiction super-soldiers and fantasy knights/warrior-monks who are the finest soldiers of the Imperium of Man, the dystopian, galaxy-spanning Human interstellar empire they are sworn to serve and defend.The physical setting of the story is the material universe or the Materium, with all action taking place in the Milky Way Galaxy in the far future thirty-eight thousand years from present. Most of this space is controlled by the Imperium, though it is not the only power in the galaxy.Other intelligent, starfaring species include the Orks, a green-skinned, orc-like race, and the Aeldari, the elf-like former rulers of a great galactic empire, the mecha anime-inspired T'au and the rapacious insect-like aliens called the Tyranids.A dynamic, galaxy-spanning story line is possible because of the existence of a separate plane of existence, the Immaterium or "the Warp." The Warp is described as a realm of pure thought and psychic energy, where the desires and emotions of the galaxy's self-aware species can take physical form, and with currents and eddies similar to a river that make traveling at FTL speeds over vast interstellar distances difficult, yet possible.As this is a realm of thought, a coalescence of extreme emotion often yields the birth of a sinister, self-aware Warp entity. The strongest of these entities are the "Chaos Gods," Khorne (a god of rage, bloodshed, and war), Nurgle (a god of despair, decay and pestilent disease), Tzeentch (a god of change, deception, scheming, sorcery, and, oddly enough, hope) and Slaanesh (a god of pleasure, pain, depravity, pride and decadence).The gods of Chaos are the result of the strongest impulses in the living souls of the universe's sentient inhabitants. Their cults have a dynamic and antagonistic relationship. Khorne opposes Slaanesh, while Nurgle opposes Tzeentch.Nurgle is the personification of stagnation, while Tzeentch personifies continuing change, Khorne personifies duty and rage, and Slaanesh personifies the epicurean or the sensual.These four powers are not the only entities in the Warp, but they are the greatest and most powerful. It is said, in the background to Warhammer 40,000, that the true nature of the Warp is beyond Human comprehension and is truly unknowable.Since it originally was created as a science fictiona spin-off of the Warhammer Fantasy Battle high fantasy tabletop miniature wargame, the Warhammer 40,000 universe contains many elements of the fantasy genre, for example the concept of magic in the form of psychic disciplines and Chaos sorcery, and adapted versions of classic high fantasy races.The inspirational sources for the Warhammer 40,000 universe include many works of classic and contemporary science fiction, horror, and fantasy movies and television series such as the Aliens franchise and the works of renowned authors of those genres such as Isaac Asimov (Foundation), Frank Herbert (Dune), H. P. Lovecraft (Cthulhu Mythos), Michael Moorcock (Elric of Melniboné), J. R. R. Tolkien (The Lord of the Rings), and Robert Heinlein. Heinlein's novel Starship Troopers in particular inspired many elements of the setting such as elite marines in powered armor, and Drop Pods in which encased Space Marines and their wargear are fired from orbiting starships down to the battlefield.Medieval, baroque, and surrealist art (especially that of H. R. Giger) have been major influences on the setting's artwork. Additionally, earlier editions of the setting were often intended to be parodies of real world historical eras, such as the two World Wars, Victorian Britain and its colonial wars, Imperial Rome, the Inquisitions of the Roman Catholic Church, and the armed forces and tyrannical governments of Nazi Germany and the Soviet Union.This mix of influences has created what is now known as the "grim dark" trope, in which every faction present in the universe is to some extent immoral and tyrannical -- though some are slightly better than others, tending towards moral greys. The Imperium, for example, is often presented as the "good guys," for better or worse, and while it may be true that there are many good-intentioned people operating within its oppressive structures, as a whole the Imperium is a xenophobic, intolerant, genocidal tyranny which is only able to maintain control of its population through the application of religious propaganda and brutal repression. However, such repression is often still better than being digested for biomatter by Tyranid hive fleets, enslaved by savage Ork warlords, or turned into the playthings of the mortal and Daemonic servants of the Chaos Gods. In the grim dark, "good" is always relative.