Veigur
A veigur (pronounced /ˈveɪɡɚ/; plural vegari, /veɪˈɡɑːriː/) is an area of the strata of Lothenmydhe set aside as a discrete unit and presided over by a djel. Each veigur typically has its own gods (though some gods may be known and worshipped on multiple vegari) and its own constellations, and may have its own sun. Other conditions may also vary between vegari, which may have unique magical effects or other differentiating characteristics. While the vegari are physically connected to each other, they very often have boundaries of various sorts between them; in effect, despite their geographical continuity, vegari can be (and generally are) considered discrete worlds, and may differ widely in their geographies, their levels of civilization, their flora and fauna, and nearly any other features.
Djili
The djili (singular djel) are powerful beings that control conditions on the vegari. The exact nature and origin of the djili is unknown; it's generally assumed that they are appointed by the gods—not the local gods of the veigur, who may not yet exist at the time of the veigur's origin, but of powerful gods with dominion on many worlds—but this hasn't actually been proven. It may be that djili actually are a sort of minor god. Regardless, the power the djili exercise over their vegari is nearly absolute, though some gods can countermand their desires. Not all djili, however, choose to exercise that power; many djili take a laissez faire approach to their dominion and very seldom take any active part in its affairs.
Djili are not disembodied forces; they do generally have physical form, though that form varies widely—some djili are humanoid, others bestial or monstrous, and others may appear like inanimate objects to those unaware of their identities. Most djili live in great lairs or palaces deep underground within their vegari, though a few rare exceptions exist who live on or above the surface. It is not known what would happen if a djel were to leave the confines of its veigur, or even if this is possible; there are no confirmed cases of its ever having occurred.
Borders
Borders between vegari may be completely open, admitting unimpeded passage from one veigur to the other. There may still be some clear demarcation between the two, by vegetation, or the makeup of the ground, or the color of the sky; or the exact border may be impossible to pinpoint by any means other than magical divination or asking the djili. More frequently, however, vegari are demarked by some sort of evident boundary, though the exact nature of the boundary could be almost anything, from a chasm to a wall or a magical barrier.
In some cases, vegari with particularly opaque and impassable boundaries may be so cut off that their inhabitants are unaware that other vegari exist. To them, the boundary of the veigur is simply the edge of the world; as far as they know, nothing lies beyond.
Relationships between vegari
Even when the inhabitants of a veigur are aware of the existence of other vegari, they are not likely to know much about them, or to give any thought to going there. Most vegari are more or less self-contained and self-sufficient, and other vegari are thought of, when they are thought of at all, merely as interesting objects of curiosity. In some cases, however, there may still be some traffic across veigur borders, and even some trade or cultural exchange between adjacent vegari. This depends largely, of course, on how permeable those borders are; subtle and easily crossed boundaries are likely to be passed over much more often than nearly impermeable walls. Those near the boundaries of vegari are likely to be the most curious and the most knowledgeable about the other worlds, thanks to their proximity to them. Again, this depends on the nature of the boundary; if the boundary cannot be seen through or traveled past, then those near it will know no more about what lies beyond than those more distant.
Any exchange of goods or customs between boundaries is usually quite limited, but there are exceptions. Rare groups of two or three (or, rarely, more) vegari have established regular trade and travel with each other, perhaps having more or less merged socially into a single world, while still remaining technically separate vegari in all other senses. An extreme case of intervegaric trade occurs with Tlateg, a veigur whose inhabitants have forged lengthy trade routes spanning multiple vegari, assimilating bits of culture and tradition from every distant people they come across.
Even if people do not travel between two neighboring vegari, however, those vegari may be linked in other ways. Many suns traverse multiple vegari on their circuits, and it's rare but not unknown for constellations to move between multiple vegari as well.
Wild Lands
Not all of Lothenmydhe is a part of a veigur; the areas of the strata that pertain to no vegari are known as the Wild Lands. Starless, godless, and devoid of any manmade structures, the Wild Lands are not generally inhabited by any sentient beings, and perhaps cannot be so inhabited—some tales have it that anyone who spends too long in the Wild Lands loses his intelligence and is transformed into an ordinary plant or animal. Even if that isn't true, the Wild Lands are dangerous in other ways; some huge and terrible beasts roam the untenanted wastes, and the darkness of the perpetual starless night makes navigation difficult and perilous.