Gangs are violent, territorial groups that can be found throughout the Imperium. Hive Worlds are known for their extensive amount of gangs. Even Terra has a huge number of gangs formed from the destitute non-adept population.
Hive world gangs are often part of the powerful rival families or clans of the hives. Some gangs (known as brat gangs) are from the young nobility of hive world cities, which descend to attack the lower-level gangs. Powerful lower level gangs are sometimes legitimized by the Planetary Government as the hive world's planetary defense forces, in order to keep down the most anarchic elements, and even to defend the planet if it is attacked. From there they may be recruited into the Imperial Guard.
Hive gangs often assume a name reflecting whatever they identify themselves with, such their territory, environment or fighting style. On the hive world of Tellus, for instance, gangs were recorded as having names such as the "Bad Rad Boys", the "Metal Maniacs", the "Screaming Scabs" and the "Zeta Death Phalangites".
- Necromunda Hive Gangs
- Nightcrawlers, a gang on Tarsis Ultra headed by the gang leader Snowdog. When the planet was invaded by Tyranids the gang saved thousands of Imperial citizens.