Anvil Vale Underdark Lore
Contents
The Three Truths
In general, the dwarves teach that there are Three Truths about the underdark:
Truth the First: The Underdark is Consuming
The underdark hungers. According to the sages who know such things, the life within the underdark that is sustained on plantlife alone is roughly a tenth of that which you find on the surface. Most creatures that consume plants – usually in the form of fungi, lichens, and the like – are also meat-eaters. The scavenger takes the place of the herbivore down here, ready and able to find sustenance not from plants in the wild, but from the remains of creatures that have died down here.
This truth is also why it's so common for underdark creatures to come surging to the surface in search of prey, as well. It is plentiful on the surface, and those creatures that dwell in the Shallows are likely to go seeking into the Daylit Lands for extra food. This means, of course, that these creatures are excellent prey for other creatures in the Shallows, and that all creatures in the Shallows are fair game for those that live in the Deeps. Food trickles downward in the underdark, such that those creatures who dwell in the truly lightless Deeps frequently are capable of going weeks and months without new sustenance, though they gorge themselves when they do finally get access to it.
For every potentially lethal feature in the underdark, there is at least one creature perfectly adapted to living right in the midst of that, allowing them to feed on what falls victim to that hazard. Creatures often develop complementary diets and a poisonous nature to one another as part of forced symbiotic relationships in this way. If one creature does not kill and eat another, it is not for lack of trying in the past, and it is likely only because they are much more effective hunters for prey that both find palatable.
Truth the Second: The Underdark is Twisting
The underdark changes. There is some force within the underdark, far from the stabilizing influence of diverse nature and settled lands, that causes transformation in its winding caverns. This transformation is sometimes the effects of other creatures which dwell in its abysses, but the underdark itself is touched by chaotic forces that reshape and alter the very rock of its bones, changing and growing and altering. The process is never quick, but it happens, such that passages marked on maps far from settlements may be visited once more to find them missing entirely.
The dwarves call this the crathadh fanas, or the "crawling void." Some believe it is metaphor, while others teach that it is literal (even if it happens in a time frame untrackable by normal mortal creatures. In essence, they teach that it's not so much that the solid living rock changes and transforms; it is instead that the empty spaces of the underdark are like creatures whose bodies are emptiness. These entities slowly worm their way through the underdark, shifting the dimensions of caverns and passages. This is the reason why in some wild underdark areas, caverns seem to shift, seal over, split where no divisions were found previous, and in general twist and change while sapient folk aren't looking.
The closer a given area of the underdark is to the surface world, and the closer it is to a civilized area, the less this effect is evident. It happens much more slowly, or even not at all, in some such areas, so that even a few days' out from a civilized area may remain relatively stable in form for dozens of years at a time, with only the most subtle and untrackable of changes. But far away in the Deeps, away from any settlements or even the lairs of intelligent creatures, some sages believe that the crathadh fanas winds its way through the otherwise solid rock of the underdark, forming and reforming entire spaces as they do so.
Truth the Third: The Underdark is Maddening
There is a reason why the only creatures who dwell in the dark vastnesses of the Deeps are either bestial in nature, utterly insane in thought, or group together in bands or larger: madness waits in the dark echoes of the underdark for any who are sentient, sane, and alone. Even those folk who ostensibly dwell all their lives within the underdark's ways, such as dwarves and many goblinoids, learn to avoid being alone in the dark. While some sages and healers believe that this is because of the inevitably maddening effect of solitude and darkness (for even most potent darkvision reveals only a certain distance ahead, casting the rest in deepest shadow) on the psyche of most normal folk.
Other sages, however, believe that whatever force it is which causes the tunnels of the underdark to twist and warp, folding back on themselves and changing perspective and location, that force affects the psyche in the same manner, stretching out and contorting patterns of thought, memory, and sense. The eternal echoing silence worms its way into the mind as surely as a worm's burrowing into the stone and soil itself, and once it has taken up residence there it flays and twists the mind of the one so affected. Returning to civilized spaces can help recover, but some who are touched by the underdark simply never recover.
Underdark Journeys
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