Hive City - Life in a Hive City: Hive Worlds are home to countless teeming billions. Their population is so dense that frequently the entire surface of the world is covered with the enormous hive cities stretching from horizon to horizon.Many hivers labour in thankless obscurity, manning huge factories called manufactorums that churn out endless streams of weapons, chemicals or other vital goods for the Imperium. Others run with violent gangs in the dark of the Underhives, living off their wits, guts and firepower.Yet, Hive Worlds are absolutely vital to the welfare of the Imperium. They are industrial worlds, producing munitions for the Emperor’s armies in vast factories, mining valuable minerals and refining fuel for the Imperial fleet.These planets are usually barren and hostile with much of the hive world's surface inhospitable, sometimes deadly to human life after centuries of pollution. The hives themselves are astonishingly large -- massive urban conglomerations, spires of adamantium and rockcrete that can cover continents and stretch for kilometres into the sky.Each hive houses millions, even billions, of Imperial citizens, and is a nation in its own right, with noble houses ruling mini-empires, trading and sometimes fighting with other hives on the same world.Palls of thick, acrid smoke cling to the lower portions of the hives below the upper sections -- those gleaming spires that rise above the world's acidic cloud cover. Only the wealthy can afford to live in the upper sections of a hive, and the working classes never see the light of the sun.Within the Spires reside the noble houses -- decadent, wealthy members of great Imperial families, or the richest merchant and manufactorum overlords. Spires contain broad, airy spaces and splendours unimaginable to those who dwell in the darkness below.Below the spires, heavy gateways and security patrols regulate passage between the upper levels and the rest of the hive. Beyond this point lies the vast bulk of the working hive -- the hive-city. The populations are often so large as to be essentially unmanageable, and the hives rely on constant recycling and imports of food and other raw materials from the broader Imperium to provide sustenance and basic materials for the teeming masses.For most people, life in the hives is tough. Conditions are squalid and unsanitary. The very air breathed by the countless hivers is recycled from the spire above and pumped through the rest of the city, growing ever more bitter and poisonous the further down it filters. Even the water is distilled from the discharge of the Upper Hive, and food is factory-produced, sometimes algae-based or spun from corpse starch.Pollution and overcrowding are the least of the hivers' woes, as gang violence and outright anarchy is part of everyday life, particularly in the lower levels. Most hivers know only their own hive-city and do not leave it during their lifetime. They never see the sky or set foot on the surface of their own planet.Their life is one of servitude in a manufactorum, coupled with a struggle for survival in the increasingly crime-ridden habitat-levels. Those few that do manage to leave the hives are often of a nervous disposition, and suffer terribly from agoraphobia.Beneath the hive-city is a lawless frontier known as the "underhive." These underhives are creations of catastrophe  -- explosions, water pollution, power failure and collapsing access tunnels are common occurrences in the lowest parts of the hive cities. Sometimes the damage is repaired, but more often than not the appeals of the refugees fall on deaf ears and the underhive expands.In this area, normal habitation is impossible, but the underhive still serves as a refuge for hive scum, criminals and the mentally unstable, though in some rare instances entire sub-cultures manage to develop and subsist in this inhospitable realm. It is a region outside the formal social structure of the hive, though some people are forced to live there as entire levels are accidentally cut off from the hive city.Heavily barricaded settlements form the only havens of order in the underhive, though even here the law of the gun is the only recognised authority, and those who go unarmed are arrogant...or foolish.Underhives are frontiers in more ways than one, and are often seen as a necessary evil. They separate the hive city from the hive bottom -- a desolate, polluted waste, long since abandoned, and partially flooded by centuries of effluence and industrial waste. In the hive bottom, the only living things are the most monstrous mutants. Sometimes these foul creatures find their way into the underhive, and in a hive city, parents scare their children with stories of sump spawn and plague zombies.Minor mutation is common in the environmental hazards of the underhive and is often overlooked by the desperadoes who reside there. However, sometimes fanatical cults, such as the Redemptionists, launch one of their crusades into the underhive to cleanse it of mutants. Some are never seen again.