One of the most interesting parts of the traditional Dungeons & Dragons lore in terms of setting has been the Underdark. Introduced in an original Gary Gygax module that began in 1978, the Underdark was an immediate sensation, and it became one of the legendary pieces of D&D worldbuilding that remains to this day. [You can read my analysis of that module--Queen of the Spiders--which I wrote while pursuing my Bachelor's degree in English.] But now that the Underdark has been around for so long--45 years at the time of this writing--it has been reinterpreted and reinvented many times. I have my own version of the Underdark, most of which was developed in response to a player to chose to play a Drow, the dark elven residents of the Underdark. I hadn't thought much about the Underdark since the Drow had never really been a part of any of my campaigns up to that point, so I decided to develop something that my player could use as backstory and characterization. The result was a sprawling world underneath the continent I've done so much work to develop. I incorporated the traditional Drow as residents of my Underdark as well as their dwarven counterparts, the Duergar. But I felt that the Underdark would be more interesting with more groups involved, so I also developed Underdark versions of halflings and orcs, both of which stray much farther from their inspirations than the Drow and Duergar do. So, below is a guide to the most important details of life in my homebrew Underdark.
[Note: Classically speaking, the Underdark has been depicted as having pretty widespread slavery. I have not changed this detail. I've written before about why you might change something like that; in this case, I chose to keep this upsetting detail because I think it serves the identity of the Underdark. If a discussion of fictionalized slavery would not be healthy for you right now, please check out the homepage for hundreds of safer articles.]
Overall:
This map shows the Underdark. If one were to lay a map of Evanoch over this map, they would be able to see that not only is this territory roughly the size and shape of the continent above, but also that the territories of the Underdark are roughly analogous to the territories of the corresponding species above. For example, the dwarven homeland is located in the southeast, at the base of the Kallett Mountains, and the Duergar territory is also in the southeast, directly under the mountains. This generally holds true of all Underdark territory, though the Drow have notably taken territory for their merchant houses beyond the reach of elven lands--this is in part because that territory corresponds to the gnomes above ground, but there are no Underdark counterparts to the gnomes, and so the territory had been contested before Drow control. The highways signified by the map are large, wide paths capable of allowing multiple large wagons to pass through--they only exist between friendly territories. The tunnels are more of military channels; these paths have been dug in order to reach enemy territories and launch assaults, but once one has been constructed, it makes both ends vulnerable to the other. You may notice on the map that all tunnels run from Drow territory to the other lands--this represents the fact that the Drow are generally the most powerful group in the Underdark and are openly hostile to all groups, while the three other groups have uneasy peace with one another, united by a common enemy. No concerted effort to fight the Drow has been able to hold together. Each of the seven territories shown above on the map have at least one passage to the surface of Evanoch, but these doors are closely guarded and rarely used. Because growing traditional crops is impossible in the Underdark, lichens and mushrooms form the bulk of the diets of humanoids and livestock alike--popular livestock includes snakes and bears. Slavery is a common practice among the mostly evil residents of the Underdark, though each culture has its own practices.
The Drow:
The Drow, or dark elves, are from the same stock as elves, and they appear almost identical apart from their nearly black skin and their pale white eyes. The Drow have very light to white hair and have generally stooped stature, which reduces the necessary height of Drow tunnels and homes. They generally wear black clothes and avoid metal accessories to avoid any reflected light.
Drowish society is matriarchal and militaristic; its leaders are the generals who command their various armies. Drow divide themselves by clan or "house," and each individual house sustains an army of its own to contribute to the Drowish society's goal of conquering the Underdark, as well as to fight against rival houses. Conflict is constant in Drowish culture, and war is not only accepted but hoped for as a way of life. The Drow are mostly devoted to the spider goddess Lolth, who is said to lead the generals of the armies. Deviation from Drowish customs is forbidden and results in severe punishment or death.
The values that motivate the Drow are wealth and the obtaining of it no matter the tactic, power and a similar focus on obtaining it despite complications, and service to one's house, though this is complicated by a focus on the individual as an important part of Drowish society. As a result, most Drow pursue their own societal advancement via money and power, and they seek to honor their house through their individual accomplishments. Although the Drow are militaristic, they do prize skill in negotiation--conflict can be costly, and being clever enough to save that money is respected. Intelligence and ambition are valued, both because they are paths to the money and power that matters so much in Drowish society. And aesthetics and hedonism also matter a great deal in Drowish society--most Drow aspire to be surrounded by beauty, especially ornate beauty, and able to enjoy life's pleasures.
Aside from perfect vision in complete darkness, the Drow have a few innate magical abilities which have both factored into their cultural lives. Firstly, Drow can create magical darkness, which greatly aids their abilities in stealth and planning ambushes. They are also able to enter a dream state--many Drow have learned to lucid dream--even while conscious. This practice is utilized in religious ceremonies, and dream interpretation is a major market in Drowish cities. Drow claim that these powers are gifts from Lolth that allow them to serve their goddess better.
Drow keep slaves for a variety of purposes: construction and personal assistance are common occupations for Drowish slaves. Drow have no reservations about taking other Drow as slaves, but the majority of slaves in Drowish territories are of the other species in the Underdark. The Drow are known to be the cruelest keepers of their slaves, commonly branding them whenever they change hands and punishing them with brutality. Between Drow of high status, slaves are traded as currency.
The Duergar:
The Duergar, or grey dwarves, share ancestry with the dwarves, and they look very much like Evanine dwarves, but they have dark grey skin, white hair, and iris-less eyes. Duergar are generally a bit shorter than dwarves but also stouter; Duergar tunnels tend to be very square, like their bodies. They wear dark colors, especially reds, blues, and greens, and pendants of precious metals and stones are common among those who can afford them.
Duergar society is very economically-minded and driven by hierarchy. The leaders of Duergar society are the wealthiest, and there is an unspoken but universally understood social hierarchy which Duergar observe. At the top are the rich, followed by religious leaders, followed by community leaders, followed by the common Duergar, followed by slaves. Acting without deference to someone higher in status results in severe punishment, or depending on the trespass, execution.
The values that motivate the Duergar begin with practicality and tradition. The Duergar believe that their ancestors found the ideal solution to every problem, so the best strategy is to follow proven methods. Most Duergar accept this--those who don't are frequently horrified by what they realize about their society and turn to lives of solitude (a great social sin to Duergar, as working together to serve is another important value. Duergar are also merciless combatants; they admire other Duergar who are especially committed to their bloodlust, and just as respected is an unwillingness to forgive or otherwise show mercy. A cultural value that has tended to unite Duergar over time is an emphasis on enduring despite difficulty--the Duergar have historically been second in prominence to the Drow, who have a stronger hold on key areas of the Underdark. The Duergar prize simple, utilitarian craftsmanship over ornate designs, and even religious tokens are created to appear without much adornment.
Duergar have abilities that have both allowed them to better protect themselves and also factored into their religious beliefs. The Duergar deity, Nordaim, was killed in a battle with Lolth many millenia ago--the Duergar consequently have something of a martyr complex, part of which gives rise to the enduring through tragedy value. It is said that Duergar obtained their innate powers when Nordaim died, a final gift to his children. Duergar are completely immune to both poison (granting them safety from the poison-toting Drow) and mind control effects (protecting them from the mental abilities of the Deeplings and Gant). They also have basic psionic abilities which allow them to manifest and control some elemental energies to create effects like moving lights, echolocation-like sounds, and vibrations in the surrounding stone, all of which are highly helpful in navigation the treacherous Underdark.
Duergar are the most notorious slavekeepers of the Underdark, and legend say that they are the originators of the practice. Duergar slaves are kept for labor purposes and for trade, but unlike other groups, the Duergar place people into slavery as a punishment. Sometimes, dissident Duergar are placed in slavery for a set time period, usually a few years, as enforcement of social order, but more serious offenses lead to life sentences. Rather than branding their slaves as the Drow do, the Duergar tattoo identification, which many claim is more humane, but the slaves argue that an unkind tattooer is not that much of an improvement.
Deeplings:
Deeplings, or rockfolk, are related to Evanoch's halflings. These small creatures stand on four legs and have thick, natural armor plating covering their bodies. They are hairless creatures with eyes which are not readily visible. Deeplings tend to dig erratically, and their tunnels curve and bend without perfectly flat surfaces, though this is no impediment to the agile Deeplings. They do not wear clothing of any sort, but some etch geometric patterns into the surfaces of their dark brown armor plating.
Deepling society is very abstract--they each have a clearly-defined role in society which is assigned at adulthood, and basically all Deeplings dutifully follow this role without question. At the bottom, though this is observed without any dishonor (since serving the whole of Deepling society is highly prized), are service people, followed by common soldiers, and military leaders at the top of society. Though unknown to Underdark citizens, the leaders of Deepling armies are actually religious leaders--clerics and priests--whose religious paraphernalia has always been mistaken for military regalia. These military leaders use their magic to heal wounded soldiers and lead with empowering spells behind them.
The values that motivate Deeplings are generally those which make them better organized; teamwork and being able to cooperate with one another to accomplish a goal is a major point of pride in Deepling society. In particular, using one's physical body in pursuit of a goal along with other Deeplings is considered highly valued--Deeplings often combine into larger forms in combination with other Deeplings. The value of destruction makes Deeplings deeply invested in destroying existing structure where it exists, especially through fighting the other denizens of the Underdark. Notably, if a Deepling is able to destroy themselves in an act that benefits other Deeplings, this is considered an especially noble act. Dominance over others is prized in Deepling culture, as is physical size--despite the smallness of Deeplings compared to other races, size among other Deeplings is part of the social hierarchy. Interestingly to most who live in the Underdark is that the Deeplings value cleanliness; Deeplings who neglect obsessive hygiene routines are viewed as degenerate.
Deeplings as a species are quite distinct from the other denizens of the Underdark. As far as outside observers are concerned, Deeplings are essentially feral. The reality is that Deeplings have a complex system of communication that involves telepathy, and the content and nuance of Deepling communication is lost on outside observers. Nevertheless, the destructive Deepling with their undying ferocity and armor plating have great potential for doing damage, and even one Deepling can stymy a small group of Underdark troops. Deeplings reside in the deepest and darkest of caverns in the Underdark, and they have complete and perfect darkvision, allowing them comfortable movement in even the most treacherous reaches of the subterranean world. They are, however, not able to comfortably exist during daylight on the surface because of the brightness of the light.
Slavery does exist in Deepling culture, but they do not keep slaves themselves; rather, they exclusively use slaves as part of trade with other groups in the Underdark. Deeplings have little interest in working with non-Deeplings in any meaningful capacity, but the trade of slaves captured in combat and raw materials pulled from Deepling territory allows them to obtain substantial food reserves and other necessities. For the Deeplings, slavery is a result of war, and neither a punishment nor an appropriate use of life; they only engage in trade in order to profit.
The Gant:
The Gant, or High Orcs, are related to Evanoch's orcs. These tall, thick-limbed creatures have pale skin and dark, curly hair which covers their entire bodies. One of the first things that people observe on sighting a Gant is its long neck, which is articulated throughout its length; in conversation, the Gant tend to move their necks rather constantly, which is disconcerting at first. The Gant build tunnels with are taller than they are wide, very much like the dimensions of a standard human door. These tunnels are notable for their perfect smoothness and levelness. The Gant wear robes, and most Gant choose fabrics which are slightly reflective--the more light that one's garments casts in the low light of the Gant's caverns, the more social standing that individual is likely to have. Especially prized are mid- to dark-colored fabrics, especially blue-green and dark green.
Gant society is very open and free for the most part. Like most of the societies on the surface of Evanoch, the Gant have a market economy and a system of employment that allows for choice of profession. Culturally, the Gant's values lead them to prize inventors highly, as inventors' advances are what allow the Gant to live comfortably in the dangerous world of the Underdark. There is little sense of a social hierarchy beyond the elevation of inventors, but where hierarchy does exist, it places intellectual pursuits over physical ones, even if it claims complete equality when a purpose is served.
The Gant value a variety of intellectual traits above all else--namely, these traits are ingenuity, forethought, and creativity. Each of these traits highlights an important aspect of Gant society. Ingenuity is prized as a way to improve life for all living beings as well as something that has allowed the mostly peaceful Gant to survive alongside their warlike neighbors. Forethought is vital in the treacherous world in which the Gant live, and it has allowed them to make due with very little support. Creativity has been the key to reacting to threats from the outside world, and everyday imagination allows for constant improvement of the technology the Gant use so much. They also value certain political goals: social equality, non-violent consolidated power, and isolationism mark Gant society, and all of these values lead to a society which has a high standard of living with relative stability. Despite these values, the Gant look on their neighbors in the Underdark as violent menaces which are little more than threats. The Gant prize competition in the social realm (but not impinging on equality), and Gant creations tend to value function over form.
Distinguished from other Underdark species by their unique bodies already, the Gant are further made unique by their inborn ability to control basic telekinetic powers. This ability exists in the Gant even as babies, and though there is a small range of strength that these powers can exist in, most every Gant has fairly comparable powers. This aids the Gant in a variety of tasks as well as making them very difficult to take prisoner, as they can control their environment even while bound and gagged. The Gant also have a remarkably high pain threshold. In Gant society, this is viewed as both a blessing and a curse--it does make day-to-day pains much more bearable, but it also means that other Underdark soldiers feel the need to test the Gant threshold of pain in brutal ways. The Gant live mostly in domed communities which protect them from attack and cave-ins; these domes are constructed of transparent but strong panels of fortified glass-alloy.
The Gant refuse to interface with slavery in any way. They believe that it violates every standard of decency, and it runs completely counter to their value of social equality. When the Gant are gifted slaves or capture opposing soldiers, they either free the slaves or give the soldiers trials. When the Gant are taken as slaves by other societies, they are known as dangerous, as they often use their telepathic abilities to free themselves and other slaves.
Cetin and The Casting Out:
Nearly three thousand years ago, the species of the Underdark had lived underground on an island continent on the opposite side of the planet. This island continent was called Cetin, and the species of the Underdark there faced a problem. The species that lived above them on the continent were always trying to destroy them. They defended themselves and dreamed of somewhere else they could make a new life of their own. They could not expand any further under Cetin--the surface was too treacherous, and there was nowhere else to go.
A Gant scientist discovered that, according to her calculations, there had to be a smaller mass of land on the opposite side of the planet. Given her measurements of the celestial bodies, the movement of the planet could only be explained by a modest mass on the other side. And so the Gant began to dig. Before long, the secret of their project got out. Within a century, the Gant's tunnel system was rivaled by those of the Drow, the Duergar, and the Deeplings. It took almost one thousand years of sustained construction, but the tunnels of Cetin's Underdark reached Evanoch. A series of natural caves and caverns was discovered, and soon, each species had its own territory claimed. The map above indicates the positions of the Underdark beneath Evanoch since--it has been a bloody standstill ever since then.
As time passed, curious residents of the Underdark ventured from the subterranean world to Evanoch's surface. They discovered that the land was plentiful and beautiful, though of course massively different than the world they had come from. Most returned to the Underdark, discontent with the bright and happy life they found there. But some stayed. The Drow took up the darkened forests of the Lathien Islands; the Duergar burrowed into the side of the Kallett Mountains; the Deeplings took refuge in the dense and dim rainforest of the south-central plains; and the Gant, who prized isolation, set up on the rocky island of Grob. They made new homes and began again here on the surface.
The species began to adapt up to the surface. The Drow became pale and grew to revere the mind-boggling natural world around them. Their superiority grew into a more reserved haughtiness. They began to record their new history in place of the old one, and the long-lived elves' story became the most trusted version of events. The Duergar had a rift: its more progressively-minded went north to the forests, using their inventiveness to forge a brand-new way of life. They organized and built the megacity of Vestry, the home of the gnomes. Meanwhile, the more traditional Duergar moved south and mined into the base of the Kalletts. Their time-honored techniques were forged, and the dwarves were soon seen as always a part of the mountains. The Deeplings found that life in the rainforest was more an individual's game than a team game, and the Deepling penchant for organized began to erode. Before long, independent-minded halflings had learned to coexist with the environment rather than trying to dominate it. And the Gant's love of competition spiked so that infighting between clans became more important than innovation; before long, the Gant had become combat-oriented with fearsome bodies to match. The days of the Gant remained underground--the orcs of Evanoch had come to stay.
By the time recorded history began in Evanoch's remembered history, any mention of the beginnings in the Underdark had either been censored or forgotten. Most cultures had stories about evolving from monstrous beasts--these are the only real echoes of the Underdark progenitors. From the earliest written texts in Evanoch's history, there is belief that the five species of Evanoch had simply always been as they are. A resurgence of tales of the Underdark came in the early 400s, and the historical record reconciles this by inventing a tale about the Underdark known as "The Casting Out."
The story goes that the five species of Evanoch (elves, dwarves, gnomes, halflings, and orcs) always lived on the continent, but they did so alongside the species of the Underdark. The creatures of the Underdark were so wicked and ghastly that the species of Evanoch were practically overwhelmed. In a move of solidarity, the species of Evanoch banded together and, in a war that lasted for one hundred years, fought every one of the Underdark species into submission. The species of the Underdark, then, were forced there as a punishment for threatening the surface.
The reality is of course the opposite in every conceivable way. But even underground, this history has been largely lost or obscured. The species of the Underdark are mostly unaware of these facts; only the most academic types have encountered meaningful discussion of the topic. Interestingly, though, those living in the Underdark of Cetin have records of all of this and even remain in close observation of the Underdark of Evanoch's situation. Most who live in Cetin's Underdark believe that leadership under Cetin has fairly advanced plans for a new journey to Evanoch's Underdark when the time is right for a renewed war effort.
So there you have it: a fairly detailed guide to the history and reality of the Underdark in my homebrew setting. Obviously, I incorporated the Underdark history into the overall backstory of my setting in a pretty big way with the ancestry idea--that's something you can do with your work. I recently played out a brief text adventure with a friend who I've gamed with for years that covered part of this history, and it got me excited to expand it here. I'm eager now that I've written this for a chance to put the Underdark war angle to use; that would be a pretty sweeping campaign. In any case, it's always good to expand your homebrew setting--you never know what exciting possibilities will pop up.
That's all for now. Coming soon: how I connect with my characters, clothing by culture in my homebrew setting, and how to figure out your style as a GM. Until next time, happy gaming!