In the game of Necromunda, the eponymous setting is a world covered in polluted ash wastes, the result of thousands of years of heavy industry with no kinds of environmental safeguards whatsoever. Scattered amidst these seas of effluent and unstable continents of compacted dross and ash are between six and nine (the source material is inconsistent) hive cities. These are massive man-made structures, reminiscent of termite mounds on a staggering scale. So large that they break through the upper atmosphere and can serve as tethering points for star ships, the hive cities are described as housing over a trillion people each. This purpose of a "hive world" like Necromunda, is to be a manufacturing center to provide equipment for the boundless legions of the Imperial Guard and Space Marines, as well as lay down new hulls for the Imperial Navy. The hive cities produce billions of tones of manufactured goods daily. In return for these services the hives are described as being supplied with billions of tons of food and raw ore every day, serviced by bevies of ships that make commutes between the hive world and neighboring planets that are mining or agricultural worlds.