Hive worlds are worlds that have an extremely high population, which is confined in massive arcologies called "hives", each of which is essentially an individual nation occupying a single massive hive city. Of the species in the Warhammer 40,000 universe, only the humans of the Imperium are known to live on such worlds. The world outside the hives is usually heavily polluted and desolate, and most hivers live their entire lives without ever having seen the outside of the tunnel network of their hive. Hive worlds often possess extensive manufacturing districts. It has been said that the sacrifice of over a million soldiers is worth "one day's hive world production" in weapons and armour.
Perhaps even more valuable is what at first glance seems to be a byproduct of the monolithic city's design. The population of any given world* approximately doubles every 100 years. With each hive housing between 10 - 100 billion people and 5 - 20 hives per planet the sheer number of citizens is staggering. And each of those citizens is a potential soldier for the Emperor's already unmatchably vast armies. Hives manufacture far more than mere steel and silica, they are vast factories for the most useful possible resource: people. It is no accident that hive worlds contribute the vast bulk of the recruits for the Imperial Guard. The often violent gangland lifestyle which most residents are forced to live is also semi-deliberate. Almost every recruit will already know how to handle a gun. Hive worlds also serve to populate newly discovered planets. Imperial citizens are gathered from various hive worlds (willingly or unwillingly) and shipped off to distant colonies. Examples of this include Medusa V and Armageddon.
In common with most other Imperial worlds, hive worlds are often based on a very obvious class system, with a ruling class and a working class, although with populations so tightly packed there develops a lower class that become violent street gangs. As can be expected, the upper classes are situated in the affluent upper areas of the hive, whilst the middle classes are situated in the middle areas, whilst the worker classes are packed together in the lower areas. The very bottom sections are often areas where the underclasses and criminals are sent to be forgotten about and obviously anarchy rules.
Some extensively developed hive worlds do not even simply consist of various enclosed arcologies surrounded by wasteland, jungle, ice, or plains. These hive worlds are completely urbanized and stacked with hundreds of layers of arcologies, covering the entirety of the planet, effectively being an Ecumenopolis. Holy Terra is an example of this "super hive world".
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Planets_of_Warhammer_40,000". The primary authors of that article are : Achnash, Pak21, CABAL, Shrumster, SAMAS, Rogue 9, Localzuk, Wiki-Ed, Nonagonal SpiderSmackBot.