Orks are a warlike, crude, and highly aggressive green-skinned Xenos race. Orks are the dominant subspecies of the Orkoids, which includes the smaller Gretchin and Snotlings. Although their society is entirely primitive and brutal, the Orkoid race is also the most successful species in the whole Galaxy, outnumbering possibly every other race. However, due to their aggressive and warlike nature, this massive race is split into hundreds of tiny empires, warring as much between themselves as against other races.[27k] In the purely theoretical event all the Orks were to unite, they would undoubtedly crush all opposition.
The Orks have had a presence in the Galaxy since that time of War in Heaven,[41] and are known to have first battled mankind long before the foundation of the Imperium, tens of thousands of years ago during the Dark Age of Technology. According to legend, the Orks were the very first alien civilization encountered by humanity - when the first ork and man met on some forgotten airless world long ago, they took one hard look at each other, drew pistols, and shot each other dead simultaneously.[36][38] Humanity and the Orks have fought innumerable conflicts since then and are unlikely to ever stop.[5] Humans and orks are two ofthe most numerous species in the galaxy, both being found nearly everywhere.[47] It is said that of all creatures, humans remain the Orks' favourite enemy to this day.
Orks were genetically engineered to be tough, muscular, aggressive and primitive-minded. In addition to their warriors (by far the most populous group), gatherings of Orks are naturally divided into a caste of Oddboyz who are genetically predisposed to perform specific tasks exceedingly well. Indeed, the Orks' creators were apparently able to encode information on how to build and maintain technology in their genetic templates; Mekboyz, for example require very little training in their function, since they understand mechanical principles at an instinctive level.
Ork "Kultur" above all else is based entirely around fighting and seeking ever-stronger or more entertaining foes. Orks always are looking for a fight, and while they prefer to fight non-Orky foes they will not shy away from fighting each other should no other enemy present itself.[19c] However, Orks do dislike fighting machines due to the lack of satisfying "feeling" or visceralness to it.[39b] The more the Ork fights, the bigger he becomes and the more respect and authority he receives from Orks around him.[25] In place of fighting, Orks will sometimes test their mettle in various other ways including arm-wrestling,[39d] squig-eating contests, and ramshackle vehicle races.[26]
Orks have a short attention span and virtually no patience. While they do not require sleep, they will do it if there's nothing else better to do. Should even this get too dull and no bigger Ork boss is around to stop them, Ork society will fall apart and they will resort to self-destructive violence.[39c]
Orks have no concept of love, and find the concept of Human affection strange. However they do have a kind of battle-bliss, and will often associate this with both love and hate. Orkoid psychology is utterly different from that of Humans, to the point where they can simultaneously believe two contradictory facts.