Today, I’ll be outlining a setting; it’ll necessarily rough, but it covers what I’ll be working on during the next month for preparation as well as being the setting that I’ll be writing a story for in November. I refer to it as either the chthonic world or as the Aragarthan Nations setting for reasons that should become clear quickly.
Without going into background details at this point, the setting is a realm where humanity found itself rather abruptly; it is a world of seemingly endless stone riddled with caverns and tunnels. Objects referred to as sun-cores provide light and a kind of anti-gravity that permits those beneath them to exist in a somewhat familiar fashion. The largest caverns are around 20-25 miles across, with a sun-core in the middle roughly a mile across. These bubbles are where the bulk of humanity – at least the civilized bulk – now lives. Given the relative distances between each such cavern and the difficulty of travel from one to the next, each one is essentially a distinct nation, giving rise to the notion of the Agarthan Nations.
As roughly a thousand years have passed since the end of what the people know as the World Before, much of what we’d recognize has been lost. The inversion happened abruptly enough that societies collapsed, mass deaths happened, and the familiar ways of doing things broke down utterly. Some things survived, at least in part. Firearms exist, but the twisting tunnels make hand-to-hand weapons much more prevalent outside the main caverns. The inversion played out in a way that largely kept cultural groups together, so the main cultures of our world have some echo in the chthonic world. Twisted forms of some religions still exist, here and there, but for the most part they’ve been supplanted by new beliefs that revolve around the World Before and the Inversion.
Gravity, as noted, is provided as an anti-gravity field by the sun-cores. This also applies to other things – the laws of physics in this world can be somewhat unreliable and broken, if you move away from the main inhabited areas. Most of the time no one would notice the unreliable portions of the world, but some areas have utterly alien physical laws, or simply chaotic ones where the answer to something as simple as “What happens if I bang these two rocks together?” can change over the course of hours. These areas tend to be relatively rare, thankfully.
Remnants of the World Before can be found scattered throughout the chthonic world; these are largely useless, as things like computers no longer have a tech base to support them, even if the data on them was still viable after a millennium, and even most books will have crumbled away to dust a long time ago. If nothing else, though, finding a site can result in a wealth of mineral resources already refined for use, as well as the occasional bit of lost knowledge gleaned from the remaining architecture and devices.
Each of the Agarthan Nations, lacking any provable center to this universe, likes to style itself as the center of everything; this is the biggest source of cultural conflict, as each of the nations has a host of reasons to back up their claim to being the centerpiece for this strange existence. This only occasionally leads to attempts at war, due to the sheer difficulty involved with travel between the caverns; it does sometimes lead to xenophobia, however.
Technology, such as it is, has found that small sun-core pieces can be shaped and used for a variety of purposes; expeditions almost always make sure that each member has one or two pieces no larger than the tip of a finger, to provide an emergency method of getting back to the walls if something goes awry as well as providing light and warmth in the Depths between each city.
Outside of the city regions, humanity has found other ways to adapt; some inhabit areas with several sun-cores creating a distinct down, living with a unified sense of direction. Others play with the effects of the sun-cores, with things like a large globe of water in the middle of a cavern with at least six sun-cores, their gravity keeping the globe suspended in the middle with a town built on the surface of the water using buoyant materials.
I’ll be coming back to this over the next month and change as I fill in the details, but this is the base structure for the chthonic world at this point. Hopefully you find it interesting!