
In addition to the main tabletop game, Warhammer 40,000 franchise includes a large variety of other media, including spin-off board games, novels, comic books and video games. The game's over-the-top, uncompromising lore has been a constant subject of jokes within the fandom, giving rise to a notable meme culture. In Warhammer 40,000 lore, events such as entire solar systems being devoured by evil gods to consume the minds of psychic humans are not uncommon. The Warhammer 40,000 universe has been described as fatalistic, brutal and uncompromising and is the prime example of the grimdark genre. The setting of the game is centered around an endless conflict between the Imperium of Man, an authoritarian human empire that comprises about one million worlds and is led by the Emperor of Mankind, several alien races, including Necrons, Aeldari, Orks, Tyranids and T'au, as well as the forces of Chaos from the parallel universe known as the Warp. The Warhammer 40,000 universe is set in the 41st millennium, a dystopian and violent future, with the tagline of the game being "In the grim darkness of the far future there is only war." The tagline gave a name to a subgenre of speculative fiction, known as " grimdark." The background and playing rules of the game's factions are covered in the game's rulebooks and supplemental army "codexes," along with articles in the Games Workshop magazines, White Dwarf and Imperial Armour.


As of 2021, the game is in its ninth edition, which was released in July 2020. Warhammer 40,000 receives regular expansions, which provide rules for urban skirmishes, planetary siege and large-scale combat. The game was created by Rick Priestley and Andy Chambers in 1987 as the futuristic companion to Warhammer Fantasy Battle, sharing many game mechanics with it.
