: A limited nuclear WW3 (the One-Hour War, the War of Gods, the Day of Fire, et cetera), global warming/climate shift, and rampaging genetic mutation has made the Earth into a world of radioactive badlands, massive deserts, swampy lowlands, and vast mutant jungles. Various post-apocalyptic and barbarian societies exist, but for the most part, the human population is composed of nomadic tribesmen. Many of the extant ruins of the past, including automated planetary ferries and intersolar beam rails, continue to function, by virtue of ancient durability and sustainable, intelligent technology.
(The ferries and beam rails are so that Earth barbarians can get to other planets for crazy adventures
: Most of the Moon's ancient surface colonies have been abandoned in favour of subterranean kingdoms; the highly-stratified, caste-based societies are ruled by semi-mutant psychic princes (so called "sorceror-kings") who battle each other for the ancient technologies of the predecessors which allow the lunar society to survive. Yongalon (once known as John Glenn City) is the greatest of the lunar burgs, and the docking point of most of the functioning lunar shuttles from Earth.Mars
: Terraformed Mars is slowly reverting to the old red desert. Like Earth, most of it's human inhabitants are nomadic barbarians, who battle for the water and resources which are so scarce in the sands. Other portions of it are ruled by ancient, warlike empires who cling to hoary traditions. In some regions, armies of autowars, robotic death-machines, roam the sands combating each other and exterminating those that they come across. There are only three functional beam rails on Mars (one is worshipped as a god by the people of the Empire of Skautas, one remains forgotten in the desert, and one is in the midst of a huge abandoned metropolis).Belt
: The inhabitants of the Asteroid Belt live at the boon of the functional mining systems and shielded Beltdweller sectors created by their ancient ancestors. Unlike many of their compatriots throughout the solar system, the society of the Beltdwellers did not experience the total collapse after the fall of Earth; instead, a stiff military dictatorship imposed itself, allowing the Beltdwellers to largely retain their understanding and control of the systems and society around them. Unfortunately, they are also sadly deluded- generation after generation of Beltdwellers have lived with the Belt Commandery's promises that contact with EarthGov will soon be resumed. They continue to send shipments of metals and materials to Earth and Mars, oblivious to the fact that they have never recieved a return transmission (except for a few confused barbarians, who the Commandery arrests as "dissidents" or "savages"). Thus, Belt society is heavily traditional, reliant on ancient beliefs; in a way, it is less a remnant of ancient tech society than a ritualistic imitation of that society.Iapetus Station
: One of the largest of the orbital Jupiterine colonies, Iapetus Station is the end-point of the beam rail to which the Skautan Martians offer sacrafices. It is dilapidated and collapsing, but retains it's atmosphere. Long ago, many of it's solar panels were damaged, and it's central computer was forced to conserve power by reserving it for only the most important functions- life support- at the expense of basically everything else. Thus, the station is dark (in some places merely poorly-lit, in others pitch black), icy-cold, and breaking down. But it is not unpopulated. In fact, it teems with human beings, if you can call the debased, semi-idiot Iapetans human. They have been reduced to gnarled, cannibalistic, gnomish beings by centuries of inbreeding within Iapetus Station's confined population. Only the influx of new blood occasionally sent from Mars allowed them to come this far without breeding themselves to death. But the Iapetans no longer use the Martians who come through the beam rail for breeding; they use them for meat.