For fifteen months Raephar had worked towards escape, since shortly after the Drow had captured him and brought him in the Wall protecting their stinking city. It had taken fifteen months to carefully gather the equipment he'd need to pass the Wall and escape, either to the surface or to death by starvation. It didn't much matter which by then. Raephar knew the Wall was not well guarded; the Drow expected no trouble from that direction. If he could get to it, he had the skill to get over it.
After the other slaves from his shift were sleeping, Raephar quietly picked his shackles, then coated himself in soot. It wasn't a great disguise, but it would work at a distance. He couldn't slip past the barracks guard, but then he didn't want to. He could quietly maneuver for a surprise attack as the guard walked his rounds. The guard's cloak provided the last detail of Raephar's disguise, and his short sword was the last bit of necessary equipment.
After that, Raephar cautiously made his way out of the city and into the fields. He found the little cache of food and water he'd hidden there, knowing the slaves working the mushrooms this shift weren't in that area. After that he walked to the Wall and climbed the ramparts unchallenged.
Looking over the edge of the Wall, Raephar saw the first snag in his plans. At the Wall's base, fifty feet below, was a wide, deep trench set with spikes. He could probably climb down the Wall unseen, but crossing the pit would take precious time he'd hoped to spend running. There was no way the guards would miss seeing him. Raephar lowered himself over the rampart and started down. He was halfway across the trench when the alarm came.
Somehow Raephar made it up the far side of the pit untouched by crossbow bolts, and sprinted away. When he was safely out of range, he stopped to take a quick look back. A drawbridge was being lowered across the trench; they'd be coming after him. Raephar hurried on until the tunnel curved out of sight of the Wall.
Out of the dim light that pervaded the Drow city, Raephar proceeded blindly and slowly. Suddenly he was moving across something soft, not a rock floor. He felt carefully and decided it was some sort of fungus. But every once in a while he found something else, something resilient and fibrous, not spongy. Raephar put it out of his mind and kept moving. Though he'd never been afraid of the dark, he found himself wishing for even the feeble light the Drow used.
There was a soft glow ahead, from an intersecting corridor. Raephar knew it was there, though it wasn't enough to see by. He peered around the corner and saw hundreds of muted lanterns in the distance, the dim kind all underworlders used. Something slithered through the stuff at his feet. As he waited, watching the lights, he heard chirping in the distance.
The Drow would be coming, and the lanterns ahead hadn't moved. Raephar decided to move on toward the lights. If they were an enemy, he didn't need to get close enough to be seen. And they might be enemies of the Drow. Besides, he liked being able to see where he was headed.
As he got closer to the light, Raephar noticed the stuff he was moving through once again. The spongy stuff was getting less common, the fibrous stuff more so. Finally he was able to see the lights were not lanterns at all. They were just lights floating in the air, like will-o-wisps, though Raephar had never heard of so many will-o-wisps being in one place. Beneath them were numerous, strange-looking plants. Something chirped loudly beside him and scampered away. Moving even closer, he found the lights had substance. They were solid glowing balls.
There was a harsh, distant clanking behind him. The Drow were coming. Raephar ran through the field of glowing balloons, startling odd animals hiding among the strange plants. Soon the entire tunnel behind him was rustling with unexpected movement. The light of an occasional balloon (Or flower? Or animal?), though it wasn't enough to clearly see his surroundings by, let him run without worrying about running into a wall. He hoped the Drow were very poor trackers, to miss the trail he was leaving.
by Michael Moran Alterio and Stephen Martin
Much has been said elsewhere about the Underworld, that vast complex of deep caverns beneath many campaign worlds, and about its more dangerous inhabitants. The great subterranean cities of the Drow, Kuo-Toa, and Mind Flayers have been described, as have the vast cavernous wildernesses between them. A good deal of time and thought have gone into these areas. It seems unfortunate that much of it is made absurd by the total neglect of a simple natural law.
"There's no such thing as a free lunch." This is as true for biology as for perpetual motion machines. Yet this is how the conventional Underworld operates. There is a gap in its ecology; it has no primary energy source.
In the real world the sun is life's primary energy source. Light from the sun, used by plants during photosynthesis, is what ultimately provides the energy needed by all life. It feeds the plants which form the lowest level of the food chain,(1) and thus feeds the entire chain.
Caves in the real world are sterile, barren places, where small and isolated creatures dwell on the knife's edge of survival. They depend entirely on food brought in from the outer world as the lowest link in their food chain. The largest creatures supported by these detrital food chains are small fish. (Creatures such as bats which live in caves but feed outside are not part of this food chain except in the amount of detritus they provide to it.)
A rule of thumb in biology says that for every pound of consumers at a given trophic level(2) in a food pyramid, there must be ten pounds of biomass(3) at the preceding trophic level. The trophic levels of a food pyramid may be graded into producers (green plants), herbivores, carnivores (possibly graded into several trophic levels themselves), top carnivores, and decomposers. Although ecosystems are actually more complex, as a general rule each trophic level feeds on the one below it. Herbivores eat producers, carnivores eat herbivores, and top carnivores eat carnivores but are not themselves eaten. For this to be the case in an Underworld fed by what washes in from the outer world, every pound of top carnivore requires 1000 or more pounds of detritus.
If we try to model a fantastic Underworld ecosystem on real systems, we quickly find that the amount of food required at the lowest link of the chain is too much to be accounted for by coming in from the outer world in the form of debris. For example, consider a small Drow community living primarily on "cattle"which feed directly on detritus. 1,000 Drow weighting 100 pounds each require 1,000,000 pounds of "cattle"who require 10.000.000 pounds of debris. Even worse, a single adult purple worm should weigh roughly 30,000 pounds.(4) As they are top carnivores, that's 30,000,000 pounds of rubbish (or more) per adult purple worm!
Detrital food chains aren't enough to explain Underworld ecology -- it would be almost impossible to supply the amount of rubbish needed, much less transport it far underground. But an energy source is needed to support the life of the Underworld, so there must be some other primary energy source.
What would this energy source be? Sunlight is not available, as it is in the outer world. Detritus will not suffice. Other possibilities include geothermal heat, radioactivity, possibly gravity, or even deeply penetrating cosmic rays. These possibilities are better suited to science fiction. This is a fantasy game, and an appropriate fantasy source is available -- magic.
As generally described, the Underworld is a vast network of tunnels and caverns. How they got there is never questioned anymore than the existence of a forest in the outer world. They are old. Maybe they have always been there.
Maybe not. Suppose there are great creatures that eat their way through the deepest parts of the world. They are magical creatures, perhaps put here by the gods of the Underworld, and they have the ability to totally consume the rock through which they move. Instead of excreting wastes from what they eat, they convert it all to energy. These Tunnelers need only a small portion of this energy themselves. The rest is released into the rock around them in the form of a magical energy that feeds the Underworld.
As Tunnelers burrow, they infuse the rock about them with energy to a depth of about an inch. The energy available to be infused in the surface of a given section of tunnel is proportional to the volume of that section, while the area it covers is proportional to its area, so larger tunnels will have a greater concentration of energy than smaller ones. And so, with one stroke, we create the caverns of the Underworld and a vast, though finite, source of energy for life there. Other GMs may use other methods, or even leave the ultimate source a mystery.
For the rest of this article, we will assume that Tunnelers did create our network of caverns. For this reason, a brief description of these creatures is in order. However, this assumption is not necessary to the principles discussed in the remainder of the article.
Tunnelers are roughly round and flat, like pancakes. They, and therefore their tunnels, vary from about 2 yards in diameter to about 200. They move fairly horizontally, so the floors of their tunnels are not usually at great angles. Small Tunnelers tend to wander more than large ones, so smaller tunnels have many turns and random loops, while larger ones have gradual turns.
Large Tunnelers occasionally split in two or, rarely, more smaller creatures. These then move off at random. Because Tunnelers move slowly (at a rate of less than a foot per month), such a division might require a long time. Similarly but much less frequently, Tunnelers may meet and merge, forming one large beast from two smaller ones. In both of these situations, and when one of the creatures encounters an existing cavern, intersecting passages are formed.
Tunnelers themselves never travel close to the surface, but when one encounters a cavern open to the outer world a passage from the Underworld to the surface is formed. Note that this passage between the worlds does not contain the magic energy used by life in the Underworld, and thus forms a natural barrier between the Underworld and the surface.
When a Tunneler meets a vein of metal ore, it splits, each half following the vein in one direction. The halves will follow the vein until it peters out or goes to near the surface, even if the vein does not run horizontally. Once the vein ends, each Tunneler will resume horizontal travel. The creature does not consume metal, only the rock around it. This imbues the metal with magical energy, much the same as the rock of the tunnels. These metal-rich caverns are much favored by intelligent races, who use the metal for weapons and trade. (Exactly what does infusing the metal with magical energy do? This is up to the individual GM. But it may not be a coincidence that Underworld dwellers such as Drow have an abundance of magical armors and weaponry.)
As the Tunneler proceeds through the rock, it leaves behind a bare, rough tunnel. Magical energy radiates from the walls of a tunnel at a rate dependent on the concentration of the energy. As energy is released from the walls of a tunnel, the concentration of energy in those walls decreases. Smaller and older tunnels, having smaller concentrations of energy, also have lower emission rates than larger and more recent tunnels. Whatever the case, it will take millions of years to totally exhaust a tunnel's magic.
Colonizer plants soon establish themselves, followed by other fast-growing and quickly reproducing organisms that take advantage of the plentiful energy. The resulting competition leads to a succession of species, each a little more specialized and efficient than the last, until a stable climax community(5) is established.
With different rates of radiation, different species of plants will develop, each of which grows best at a different rate. From this variation different biomes can develop, each dependent on a different rate of energy release. This provides for diverse ecologies which have long lifespans gradually ending as the energy runs out. Thus as the amount of energy radiated in a tunnel decreases, the ecosystem in that tunnel slowly changes from a diverse system thriving on a high radiation rate to a system which can survive on less available energy.
What kind of life lives in the caverns? Practically anything. Following are some ideas and general characteristics of that life, grouped by trophic level, and then some notes and details on different biomes.(6) These are usually modeled on actual forms, with some logically resulting variations.
The primary producers of the Underworld are plants that use energy from the primary source directly. Primary producers use energy as it becomes available -- that is, as it is released from the rock. As photosynthetic plants do in the real world, "magic-synthetic" Underworld plants use inorganic substances and energy from their primary source to produce food.
Primary producers are the lowest link in the food chain. As byproducts they produce carbon dioxide and many essential nutrients.
The simplest of the Underworld plants grow directly on the rock and take nutrients in from it and the air. These colonizers resemble mosses, with no leaves or stems, and they completely cover the walls and ceilings. Colonizers eventually die and fall to the floor, where decomposers break them down, forming soil. In time this process levels the floor of the tunnels, so that old tunnels are not round, but rather flat-floored with the walls forming an arch.
With the development of soil, nutrients become available and primary producers develop root systems to obtain them. Rooted floor plants grow almost entirely underground as large, broad, this "leaves" lying between the rock below and soil above. The roots extend up into the soil to gather nutrients; the broad leaf against the rock absorbs energy. Round flower-like structures might extend above the soil for reproduction and to absorb or release gases as needed. Such structures would vary according to the species of plant.
Rooted wall plants are usually vine, with root systems connected via long, slender stems to energy gathering leaves on the wall. Such plants would resemble ivy, except that rather than facing out the leaves would lie flat against the rock in a continuous sheeting.
In the center of the ceiling might be some plants whose stems could not climb the wall, but rather hang down to the soil. These stems would be unusually tough and fibrous, but not woody. Such plants would have multiple stems, like the banyan tree, rather than a single lifeline, so that the loss of one relatively fragile stem would not outright kill the plant.
Primary producers could also be rootless, obtaining nutrients from non-soil sources. Some, such as colonizers, might draw nutrients from the air or rock. Parasitic plants could obtain nutrients from other plants. Rootless plants are easily imagined. They would grow primarily on the ceiling, and also compete with rooted plants for wall space.
Secondary producers use non-magical energy and nutrients to form food. Two examples are light-using (photosynthetic) and heat-using (thermosynthetic) plants.
Where light is available, photosynthetic plants often grow. As with their outer world counterparts, they have stems and leaves. Unlike their outer world counterparts they are black, as they must absorb and use many frequencies of light, including the green ones.
Where heat predominates, such as near volcanoes or in the largest of tunnels, other plants grow. Instead of feeding on light, they feed on infrared radiation/thermal energy. At least one producer of this type is found in the AD&D world -- brown mold. Others may exist, and will actually be important for temperature control.
Herbivores are creatures which feed off of producers. Most are small in the Underworld, and will not be discussed in detail. With almost three fourths of the primary producers growing on walls and ceilings, small flying and climbing herbivores most efficiently exploit the abundance. These creatures closely resemble their terrestrial counterparts -- bats, chipmunks, monkeys, flying squirrels, climbing lizards, and a plethora of insects. There might also be giant sized varieties of very small mundane herbivores such as caterpillars, butterflies, beetles, and so forth. To be successful, all these arboreal creatures must be small; larger creatures would find climbing and perching excessively difficult, and would be less likely to survive falls.
Larger herbivores are primarily floor dwellers, and range from creatures rather like small cattle to truly great insects to the more mundane. A wide variety is available, including rothe, giant boring beetles, Underworld counterparts of rabbits, and so forth. Others can be easily imagined.
Herbivores are interesting to adventurers mainly in how they protect themselves. Some may be camouflaged, others capable of great speed or flight, others still defended by quills, hard shells, large numbers, musk, keen senses, or noteworthy offensive capability. For the most part, herbivores are non-aggressive, and retreat if given the chance.
Two conspicuous types of terrestrial herbivores are missing from the Underworld. These are birds and the swift hoofed mammals. The swift runners are missing because they are distance runners. Although speed per se is valuable for defense, the crowded corridors and narrow spaces of the Underworld remove any advantage a distance runner may have over predators. Runners who also jump, such as rabbits and kangaroos, are better suited to the environment.
Birds are missing and their niches filled by insects and bat-like mammals. The Underworld lacks safe nesting places; a bird's nest would soon be robbed, while insects lay so many eggs that a few always survive, and bats bear their young live. Also, birds are generally adept at long flights; bats and especially insects are more maneuverable. Thus birds are poorly suited to the Underworld.
Carnivores are secondary consumers, creatures whose diet consists mainly of flesh. The ones that prey on small climbing creatures are themselves usually small and just as capable of getting around. These carnivores, with the exception of those that hunt in groups, usually won't attack anything much larger than themselves. A good prototype for this type of creature is the carnivorous flying squirrel; other Underworld varieties could easily be developed. Most would emphasize the senses of scent and sound, and be primarily arboreal.
There are, of course, larger creatures to be found in the Underworld, wherever there is enough suitable prey to feed them. They employ a variety of hunting strategies, which can be used to distinguish ecological niches. Some examples of these follow.
Hunters who stalk and pounce: These carnivores are often silent and are capable of bursts of great speed. Many can leap or are trackers. Examples are cats of all sorts and hunting spiders (not web-builders).
Hunters who hide and pounce: These carnivores lay in wait and them ambush prey. They have camouflage ability, which may even include control of their skin temperature to escape detection by infravision. They can remain still for long periods. Examples are preying mantises, crocodiles, ropers, and lurkers above.
Pack hunters: These creatures overwhelm their prey with numbers. A pack coordinated enough to trap prey from both sides in a tunnel would be most effective. Examples include wolves, stirges, giant ants, and piranhas.
Hunters who trap: These carnivores build traps and wait for prey to stumble in. Like those which hide and pounce, they are masters at camouflage and immobility. Examples are web-building spiders and ant lions.
Hunters who lure: Some secondary consumers attract prey through trickery. They may use scent, light, heat, water, or other lures to do so. Many carnivorous plants fall into this category. Magical varieties on this sort of creature may use charm or illusion. Examples of such creatures include trappers, angler fish, snapping turtles, and wolves-in-sheep's-clothing.
Gatherers: Some creatures are omnivorous, eating both plants and flesh. Typical of these are those that gather available food -- leaves, berries, fruit, insects, grubs, honey, careless or unlucky herbivores, and so forth. Some are more dangerous than others. Examples include bears and apes.
These creatures are not prey for any other. They are generally large or even huge, with formidable offensive and defensive capabilities. Fortunately they are rare, since they need such a vast supporting food chain to survive. Examples abound in the game references (being the more interesting and deadly encounters) -- such as beholders, intellect devourers, behirs, tunnel and purple worms, umber hulks, and aboleths. Intelligent varieties will often have allies or slaves, and traps or similar safeguards and labor-savers.
These consumers are vitally important for recycling nutrients. Decomposers live off of dead organic materials. The vast majority are harmless, and small or even microscopic. A few are larger and might feed on available living creatures. The latter type include oozes, puddings, gelatinous cubes, and so forth. Another noteworthy variety is fungal decomposers. Some soil fungi grow to large sizes, and thus it may be possible to find giant puffballs, bracket fungi, and even forest-like stands of giant mushrooms. Intelligent races often cultivate fungi such as truffles and edible mushrooms.
Symbiotic organisms are organisms that live off of each other while helping each other. Lichens, consisting of a fungus and a plant, are a good example, as are certain Pacific jellyfish which feed in part off a plant which grows in their transparent bodies. In many cases, one of such a pair will be a hunter of some sort.
Organisms that use others for food, to the host's detriment, are parasites. There are both plant and animal parasites. A successful parasite will not kill its host, since it would then have to find a new one. However, a parasite suited to one type of host could end up killing another. For example, the parasitic fungus that killed off the American Chestnut actually lives best in an Oriental Chestnut, which it does not kill. Other parasites include tape worms, athlete's foot, mites, and ticks. The dangers represented by parasites are at their greatest in such things as ear seekers, assassin bugs, and rot grub.
A great variety of potential ecologies exists for the Underworld. In the outer world, ecologies depend on temperatures and the availability of water. These are also important in the Underworld, but the primary determinant is the rate of emission of magical energy. A GM determines a biome by setting a value for each factor in a tunnel. These three factors and others are detailed hereafter.
Energy is important as the source of life, for producers need it in one form or another to create food. As the ultimate source of life in an area, if provides the basic shape for that life. A greater amount of energy can sustain a greater amount of life, in both abundance and variety of types. That is, in areas with high energy outputs (ie: larger and more recent caverns), many species of plants and animals will exist. These species will specialize in very particular niches. Few nutrients will be stored inorganically in soil because most will be caught up in living organisms. This situation is roughly the Underworld equivalent to a tropical rain forest.
If little energy is available, there will be a lower population density. Fewer species will exist, and these will not specialize greatly. Instead, each will use a variety of strategies to eke out a living. Because the various organisms lack the energy needed to exploit nutrients, there will be a surplus of these in the soil. This biome is comparable to arctic tundra.
Between these two extremes is a great range of possibilities, which will be tempered by other determinants. As a rule, the smaller and older the tunnel, the lower the rate of energy released, and therefore the less abundant and varied its life.
There are three factors that determine the temperature of an Underworld ecology: First, temperature increases with depth underground, as in the real world.(7) Second, all living things produce heat as a byproduct. In the outer world this radiates into space, but in the Underworld it is trapped. All other things being equal, a high energy tunnel (with more life) will be hotter than a low energy one. Lastly, there are certain plant-like organisms, such as brown mold and possible other thermosynthetic producers, that use heat as their main energy source. Where these grow, it will be colder than otherwise.
By juggling these three factors, a GM can select any temperature desired. Once set, temperatures in an area are constant. There are no seasons in the deep Underworld. Tunnels close to the surface may be affected by seasonal weather in the outer world -- temperature variations, droughts, or floods. These will affect the tunnels to a much lesser degree than they affect the surface. Otherwise weather is minimal and temperatures are constant.
In general, at higher temperatures creatures are more active, especially cold-blooded organisms like reptiles, insects, and mobile plants. Creatures unable to regulate their internal temperature can tolerate external temperatures ranging from freezing to about 120 degrees Fahrenheit, where proteins break down. Regardless of energy availability, very hot or very cold conditions will limit the kinds of organisms that can survive.
Noticeable weather occurs only where there are large temperature gradients. Moist, warm air meeting cold air can produce fog, light rain, or even snow in cold places. This will generally occur around tunnel intersections. Here, too, there might be winds.
All living things need water, and if it is not available, or is overabundant, it will control the kinds of creatures present. Water may leak in from the surface, or it may derive from natural underground sources. In either case the result is underground streams, rivers, or lakes. When such water is not otherwise available, primary producers can use magical energy to create it from the air, along with other nutrients.
In dry areas, creatures will hoard water. Adventurers may even be attacked for theirs. Some plants might condense water from the air. Others will travel in search of it. In wet areas creatures will be amphibious or aquatic. Water breathers will live in open water. Real world models can be used in these situations.
Although darkness prevails in the Underworld, it is entirely possible to envision relatively brightly lit regions. Primary producers might create light, or other creatures might use more conventional forms of bioluminescence. Even though creatures that have evolved long in the Underworld may not use light to see, those which have migrated in from the outer world will. Creatures might use light to communicate, attract a mate, lure prey, or even as a weapon. Where there is light, there will be photosynthetic plants. Organisms will use different colors, and vision will be common among the local creatures.
Where it is dark, emphasis will be placed on senses other than vision. Creatures will be better at perceiving sound and odor. Heat detection, as found in pit vipers, and infravision will be developed, as will sonar. More esoteric mundane and magical senses may also be found: detection of electrical fields (as in sharks and eels), air vibrations,"life force,"and so on.
These other senses have advantages and disadvantages over vision, and may lead to some apparently inexplicable behavior. Sightless animals will be unaffected by magical light, darkness, invisibility, and visual illusions. The senses used to replace sight might give other advantages as well. For instance, a sonar-using creature may be able to "see"around corners. Creatures using other senses may be especially susceptible to unusual heat sources, strong odors, audible glamours, and the like, depending on what senses they use.
These could also lead to unexpected reactions. For example, an organism which was running from a character party may suddenly turn and fight as if trapped, even though the tunnel continues on. At first this may seem bizarre, but if the characters, after killing the beast, walk into a nest of volts, they might realize the beast had sensed the electricity.
In dark areas, creatures may be colorless or white, as is generally found in real caves. On the other hand, since there is no light for their enemies to use, their coloration will not be useful as camouflage and could appear bright and garish if exposed to a light source. As example of this would be the fish always shown in undersea documentaries; they are easy to see in a diver's light, but not in the light that naturally filters to the depths at which they may be found.
Not only will tunnel size determine energy emission rates, it will also dictate the kinds of organisms that can live there. Creatures whose main defense is to run away will be more easily trapped in small tunnels, and therefore less common there. Larger predators may not be able to fit into these tunnels. Lower level adventurers will be well advised to keep to the small tunnels, which cannot support as many dangerous predators.
Generally, each area in the Underworld is constant and unchanging. There are no seasons, no weather, no temperature variations, not even night and day. Competition for available energy and nutrients intensifies among the creatures living there. These factors encourage specialization, as each species must put all its effort into efficiently exploiting a single ecological niche. This reduces competition; each species has staked out its own territory and does not intrude on others. The result is a set of very complex and stable relationships between species that become interdependent. Such communities change with time only slowly, as the rate of energy emitted gradually decreases.
Although these communities are stable, they are not resistant to change. External forces that intrude on such a community can cause drastic alterations. For example, adventurers may move through an area, killing the major carnivores. Herbivores will have a heyday, rapidly eating all of the plants without getting eaten themselves. Then the herbivorous population will crash as their food runs out. Plants which may not have been able to compete with stable communities of other plants may dominate the flora when it is able to regrow.
One of the naturally occurring major changes that may affect such communities occurs when Tunnelers intersect old tunnels. Different ecologies come into contact, disturbing the balance of each. Often one will triumph over the other.(8) Other natural catastrophes that could cause change include earthquakes, volcanic activity, floods, and so on.
Migration in the surface world is a response to change. Lacking such change, Underworld organisms tend to stay in one area. Extreme specialization reinforces this. Given such isolation, species will differ in different areas. Certainly this will be true for unconnected tunnels, and it may be true for separate regions of the same tunnel.
Another result of this lack of change is a lack of hibernation in Underworld creatures. Not only do the animals not sleep through the winter, but the plants do not undergo the same growing seasons that they do in the outer world. Instead of all flowering at roughly the same time, bearing fruit together, and so forth, different Underworld plants, even though they are of the same species, will exhibit different growth stages at any given time.
There is no universal flora and fauna of the Underworld. Certain patterns will be common, as identical niches elicit similar adaptations from species in different areas. Many or even most creatures in a newly explored section of tunnel will resemble known varieties found in other areas. And these "known" creatures will be much the same as those encountered before, as they have adapted to identical niches. But this similarity could hide a deadly difference. And not all creatures will be the same everywhere; explorers will continually encounter new creatures.
There are many intelligent races in the Underworld. Some "savage" races will coexist with the ecosystem. These hunter/gatherers could be modeled culturally on American Indians or African Pygmies. They are not typically from the outer world, and do not include vision among their senses. Thus, the areas where they live need not be lighted. These races will be at pre-agricultural stages of civilization. This is likely to, but not guaranteed to, indicate that they also lack knowledge of other sorts, such as metal-working.
Civilized races have knowledge at least of agriculture, and maybe more. They will emphasize short, simple food chains to most efficiently use the available energy. Most of them do not belong to the previously described ecological communities, because they use agriculture and domesticate animals. Thus, for example, even though they themselves are top carnivores, Mind Flayers may feed on slaves fed on producers, cutting out the normally intervening layers of carnivores. Oddly, most civilized races were once exiles from the surface world, and do use vision.
In addition, some intelligent species, including mongrelmen, jinxkin, boggles, and doppelgangers, live as parasites on the fringes of societies. They do not produce the goods they need themselves, nor lord over those who do. Rather, these creatures normally take what they can from the civilized races of the Underworld, although they are just as happy to take from adventurers, and make do when they can't take what they want. These creatures, too, are not truly part of the ecological community. Like the civilized creatures, they use light, and most once lived above ground.
In areas held by civilized races, encounters will differ from those in wilderness areas of the Underworld, and danger will come from different situations.
Civilized Underworld races alter their environment in other ways, too. They are often accomplished miners and delvers, and may carve out non-magical tunnels and caverns. Over the centuries these may become very extensive. Those races exiled from the surface will have well-lit caves -- both an attraction for and warning to adventurers.
The Underworld is a strange place to adventurers from the outer world, and those who enter it unprepared are courting death. Because the environment is so unlike their own, characters don't know what is a threat and what isn't, what to eat, or if they'll be able to find water. As the home of the most evil civilizations, the Underworld is"enemy territory"for adventurers. They need to be prepared for whatever emergency may arise, no matter how unlikely, because there is nowhere to go for aid.
Play in the Underworld is likely to be hampered by scale. A scale which is convenient for caverns several miles long is not convenient for mapping the small corridors. However, as has been pointed out, the small corridors are generally safer. At this point, one of the features of Tunnelers becomes handy.
Small Tunnelers wander. Their tunnels should be some of the worst mazes ever, and in a fairly centralized area. So when a GM maps out a region of the Underworld, he can simply draw dotted lines around an area where a small Tunneler has been. It is assumed that a party can reach any spot in the dotted region from any other by wandering through the correct tunnels.
However, the party is likely to get lost on the way. Assume that they will get lost if they don't have some way, such a gnome in their midst or a magic item, of determining direction and travel underground. A surface dweller's ability to determine direction is useless in the Underworld, for the indications are different, and these mazes are too difficult to map. A party which gets lost in the Underworld can end up going in any direction, even the one they want to go in, or they may wander in circles.
The Underworld is an innately magical place, and a few spells will have unusual effects there.
Detect Magic is almost useless -- an ever present background of magical energy will mask all but the most powerful spells and magic items.
Anti-magic Shell will remove all magic from the areas it encounters; thereafter no primary producers will be able to grow in these regions. These areas will quickly grow barren, eventually becoming like real-world caverns.
Dispel Magic will release the magic from the rock affected. This energy will be dispersed throughout the area of the spell. Growth in the area will no longer be limited by the rate at which the magic flows from the rock; energy will be there for primary producers to take as they need, as long as it lasts. Eventually the area will become barren, as with the anti-magic shell, but first there will be a riot of growth which chokes up the tunnel, until all energy is used up and no life can be supported. And long after the region ceases to feed producers, scavengers and decomposers will be able to thrive there on the surfeit provided by the growth riot.
Spells similar to those above may have similar effects, to be determined by the GM.
Spells which work on plants in the outer world may or may not work on non-photosynthetic plants of the Underworld, at the GM's option and provided he is consistent. These spells include priest spells of the "plant" sphere and the mage spell charm plants. Plant Door should almost certainly not work on such plants.
Druids may memorize spells in the Underworld. This might seem obvious to some people. However, since druids "hold trees (particularly ash and oak), the sun, and the moon as deities,"(9) and these are not available in the Underworld, this point needs reiterating. The Underworld is a part of the natural world, and druids are not limited in the levels of spells they may memorize while there.
Intelligent creatures in the Underworld may fashion weapons or other items out of rock or metal infused with magical energy. At the least, these items could be used to affect creatures hit only by magical weapons. Some creatures might be able to enchant the items to instill other magical properties.
The primary producers of the Underworld slowly absorb magic released by the surrounding area. What is there to stop them from taking it from magic items brought into the Underworld? Well, nothing, but for the amount of time characters are likely to be in the Underworld no damage is going to occur. The magic is not siphoned from the items by these plants, the plants simply consume what the items give off. Only items in very old treasures will have been drained, although all magic items lying around will be plant-covered.
However, any magical item taken into the Underworld will attract magic-using plants. Proper maintenance by the characters will keep these items useful and easily accessible. Simply not leaving an item lying around until a plant can start growing on it will do wonders. Moving it around every few days will protect it from the majority of primary producers, which require soil as well as magic. To protect an item from those few producers which don't need soil, it should be inspected weekly and cleaned off when necessary.
Failure to follow these precautions could result in being unable to find a shield in the undergrowth, identify which end of a wand is which under its mold-like coating, and so forth. More critically, it could result in the plants absorbing part of the magic released should the item be used while they are on it, perhaps wasting a charge and certainly wasting an action for the round.
As found in the official references, most underground encounters are with "civilized" races or top carnivores. While these are dangerous and therefore exciting encounters, having to face unknown creatures can be as exciting, and often more challenging. This article has demonstrated an Underworld deserving a plethora of life. Use it to its fullest.
GMs may balk at creating a number of new monsters. They may not have the time, or may not want to put much work into a region the characters don't visit often. This much work isn't necessary. Many of these creatures have their counterparts in the upper world. A GM needing a creature on the spur of the moment can give a general description and then look up the counterpart in the Monster Manual. Another short-cut to Underworld encounters is the development of common pattern monsters. These creatures would fill common ecological niches, and thus be similar in most respects throughout the Underworld. The GM, after creating the monster, could use it in several areas, changing it in one or two respects each time.
Vast as the Underworld is, encounters should be treated more like wilderness encounters than dungeon encounters. That is, with the variety of creatures in a given area, encounters will be with monsters of a variety of levels, not with those of a small range only. Also like the surface, the Underworld will have regions inhabited by intelligent races and others which aren't. Those which are inhabited by civilized monsters will doubtlessly be patrolled.
Because conditions are constant, barring catastrophe, at any given location in the Underworld, there is little migration. Creatures with no lair may wander a bit as long as they stay within a tolerable environment, and some creatures -- especially top carnivores -- may wander because of the amount of food they need. But even they tend to mark out a territory and keep to it.
An overwhelming fact of Underworld life is that it is essentially one dimensional on the large scale, whereas outer world wilds are two dimensional. That is, the farthest distance you can get from a passer-by is equal to the diameter of the tunnel, and the practical distance may be less. You can't go around an encounter. You either go through or back off.
To a traveler, the tunnel is essentially a street, with roadblock after roadblock. Since most creatures stay put, a GM rolling encounters should record what is found where; the odds are it will still be there if and when the players return.
The following tables, using a roll of 1d12+1d8, are suggested for Underworld encounters. Specific monsters are not named to allow for variety. GMs are encouraged to make up tables with specific monsters for the different regions of their underground caverns.
| Roll | Patrolled Tunnel | Large Tunnel, Wild | Small Tunnel, Wild |
| 2 | Top Carnivore | Top Carnivore | Top Carnivore |
| 3 | Carnivore 3 | Carnivore 3 | Carnivore 3 |
| 4 | Carnivore 2 | Carnivore 3 | Carnivore 2 |
| 5 | Carnivore 1 | Carnivore 2 | Carnivore 2 |
| 6 | Scavenger | Carnivore 2 | Carnivore 1 |
| 7 | Raiders | Carnivore 1 | Carnivore 1 |
| 8 | Herbivore | Carnivore 1 | Carnivore H |
| 9 | Herbivore H | Herbivore | Herbivore |
| 10 | Herbivore H | Herbivore | Herbivore |
| 11 | Patrol | Herbivore H | Herbivore H |
| 12 | Patrol | Herbivore H | Herbivore H |
| 13 | Patrol | Carnivore H | Carnivore H |
| 14 | Allies | Carnivore H | Carnivore H |
| 15 | Thief | Plant/Fungus | Parasite |
| 16 | Carnivore H | Parasite | Scavenger |
| 17 | Carnivore 1 | Scavenger | Patrol/Raiders |
| 18 | Carnivore 2 | Patrol/Raiders | Plant/Fungus |
| 19 | Carnivore 3 | Carnivore 3 | Carnivore 2 |
| 20 | Plant/Fungus | Top Carnivore | Carnivore 3 |
The encounter classifications follow, with examples. Many of these examples are above-ground creatures whose counterparts could be encountered. It is assumed that all encounters, regardless of whether the creature is potentially dangerous or not, are of a sort which seems dangerous at the time.
Care should be taken to make the monster fit the locale when using analogs. For instance, an underground basilisk will either be found in a lighted area, not have its magical attack, or have some other means (such as a breath weapon) to turn opponents to stone. Note that the second of these options drastically decreases the creature's power; the third may increase it.
Herbivore H: Inoffensive plant eaters which can offer little or no physical harm to the characters. Typical attacks by such creatures will do no more than 1d2 points of damage a round. Examples: Denzelian, some Minimals, and Squirrel.
Herbivore: Plant-eaters which do have potentially damaging attacks or unusually powerful defenses. Examples: Al-Mi'Raj, Baboon, Giant Bee, Giant Fire Beetle, Giant Stag Beetle, Cave Cricket, Dragonfish, Giant Firefly, Slail Snail, Hippopotamus, some Minimals, Giant Porcupine, Rothe, Giant Slug, and Witherstench.
Carnivore H: A carnivore that won't normally attack something as large as a man, and which has attacks doing no more than 1d2 points of damage each. Examples: Bat, Giant Bat, Cat, Huge Centipede, Giant Centipede, Poisonous Frog, Jackal, Kampfult, some Minimals, Otter, Skunk, Poisonous Snake, Large Spider, Carnivorous Flying Squirrel, and Weasel.
Carnivore 1: Carnivores which are capable of threatening small herbivores but not most other creatures. Examples: Badger, Barracuda, Warthog, Bowler, Giant Crab, Dog, Giant Eel, Weed Eel, Flumph, Giant Frog, Killer Frog, Gorbel, Hoar Fox, Hyena, Jaculi, some Minimals, Large Pedipalp, Huge Pedipalp, Pseudo-Dragon, Quipper, Sting Ray, Constrictor Snake, Giant Toad, Black Urchin, and Red Urchin.
Carnivore 2: Carnivores who might make a meal of creatures in the"carnivore 1"classification. Examples: Giant Ant, Ape, Babbler, Black Bear, Giant Water Beetle, Blindheim, Bonesnapper, Caterwaul, Cave Fisher, Cave Moray, Megalocentipede, Cheetah, Giant Crayfish, Crocodile, Death Dog, Electric Eel, Firedrake, Fire Toad, Garbug, Gorilla Bear, Hook Horror, Giant Hornet, Hydra (5 or 6 heads), Jaguar, Kamadan, Leopard, Mountain Lion, Giant Lizard, Giant Lynx, Osquip, Giant Otter, Giant Pedipalp, Giant Pike, Piercer, Huge Scorpion, Large Scorpion, Giant Constrictor Snake, Huge Solifugid, Large Solifugid, Giant Water Spider, Huge Spider, Tiger, Poisonous Toad, Land Urchin, Red Urchin, Yellow Urchin, Volt, Giant Weasel, Wolf, Dire Wolf, Wolverine, Giant Wolverine, and Yeth Hound.
Carnivore 3: Dangerous flesh-eaters, which regularly attack creatures classified as"carnivore 2." Examples: Brown Bear, Cave Bear, Northern Bear, Blink Dog, Giant Boar, Wild Boar, Cockatrice, Giant Crocodile, Devil Dog, Doombat, Giant Dragonfly, Giant Gar, Grell, Hydra (7 or 8 heads), Lion, Spotted Lion, Fire Lizard, Minotaur Lizard, Subterranean Lizard, Rock Reptile, Giant Scorpion, Tentamort, Slithering Tracker, Giant Poisonous Snake, Giant Spitting Snake, Giant Spider, Phase Spider, Storoper, Sabre-tooth Tiger, Silver Urchin, Giant Wasp, and Worg.
Top Carnivore: Carnivores which are only rarely the prey of other creatures, if ever. Examples: Basilisk, Greater Basilisk, Behir, Giant Rhinocerous Beetle, Beholder, Dragon (any), Ettin, Gorgon, Hydra (9+ heads or Laernian), Intellect Devourer, Lurker Above, Mimic, Neo-Otyugh, Purple Worm, Roper, Trapper, Tunnel Worm, Umber Hulk, and Will-o-Wisp.
Plant/Fungus: A plant or fungus with properties that make it dangerous to characters. Examples: Ascomid, Basidirond, Bloodthorn, Choke Creeper, Forester's Bane, Violet Fungi, Green Slime, Mandragora, Mantrap, Retch Plant, Brown Mold, Russet Mold, Yellow Mold, Shambling Mound, Shrieker, Slime Creature, Olive Slime, Strangle Weed, Giant Sundew, Tri-Flower Frond, Twilight Bloom, Ustilagor, Whipweed, Witherweed, Yellow Musk Creeper, Yellow Musk Zombie, and Zygom.
Parasite: A creature which feeds off of a host or uses a host to feed its young. Examples: Assassin Bug, Giant Bloodworm, Ear Seeker, Galltrit, Giant Horsefly, Lamprey, Giant Lamprey, Land Lamprey, Giant Leech, Stirge, Throat Leech, and Giant Tick.
Scavenger: A creature which feeds primarily off of dead material, but which is dangerous in its own right. Examples: Black Pudding, Giant Bombardier Beetle, Giant Boring Beetle, Carrion Crawler, Cifal, Crystal Ooze, Giant Housefly, Gelatinous Cube, Gray Ooze, Mustard Jelly, Ochre Jelly, Otyugh, Deadly Pudding, Rat, Giant Rat, Rot Grub, Scum Creeper, and Stunjelly.
Patrol: A patrol composed of members of the underground race living closest to the site of the encounter. Possible races include: Aboleth, Bullywug, Cloaker, Crabman, Dark Creeper, Derro, Drow, Duergar, Gargoyle, Gibberling, Grimlock, Kuo-Toa, Lava Children, Margoyle, Meenlock, Mind Flayer, Myconid, Pech, Svirfneblin, and Troglodyte.
Raiders: A war-party composed of members of an underground race which is the enemy of the race living closest to the site of the encounter. Potential races are the same as for a patrol.
Allies: A party composed of members of an underground race which is an ally of the race living closest to the site of the encounter. Potential races are the same as for a patrol.
Thief: A group of intelligent creatures which live at the edges of and prey on an underground civilization. Examples: Boggle, Doppelganger, Drider, Jermlaine, Meazel, Minotaur, Mite, Mongrelman, Snyad, Troll, the various Undead, Vargouille, and Wilstrak.
By definition, harmless encounters are innocuous. But to a newcomer to the Underworld they may seem fraught with danger. In actuality they are dangerous only to the abysmally ignorant (ie: the average overworlder).
The GM seeing "herbivore (harmless)" on an encounter table is all too likely to say, "You see some small animals eating leaves. They run away when they see you." The possibilities go far beyond that. Even a harmless encounter can be fun, informative, and/or infuriating for characters. There are many smaller herbivores and carnivores that adventurers will never see, barring perhaps an observant druid, because these creatures survive by keeping clear of large, noisy things like adventurers. It might be useful to remind adventurers of this, though, by mentioning glimmering eyes, noises, and so forth, and by telling observant characters some of what they glimpse.
As adventurers become acquainted with a given tunnel's harmless encounters, there is less need to dwell on them. In this case, truly innocuous encounters should be treated as no encounter.
Site Map | 8 February 99
copyright © 2001 by Michael Moran Alterio, Michael Babriecki, Harry Ching, Stephen Martin, and Donald R. Parrish III (all rights reserved)