Book of Elements (3.5e Sourcebook)/Environments of the Inner Planes

There hasn't actually ever been a description of the elemental planes where they at work in a way that's really great to play in. They also haven't gotten a detailed standardized write-up anywhere, leaving little bits of information scattered across three or more editions worth of books and modules. Here's a version of the elemental and inner planes that is self-consistent and playable, and more detailed than the 3.5 rulebooks. The High Adventure section, next, will address adventure hooks for these planes.

Generalities

All elemental planes are places of continuous destruction and rebirth; their element is continually being destroyed in sinks and spat out again in other forms by sources all across the plane, although the forms these sinks and sources take are always different from plane to plane. Likewise, a sink or source seldom stays in the same place, and often disappears entirely or opens out of nowhere. Sources act to counteract sinks, removal of material from the plane, and destruction through effects like Disintegrate, and so every plane actually has more sources than sinks at any given time, at least if you consider amount of material produced or consumed. These Planes also all have traits to enhance appropriate magic and impede opposite magic, and are all quite sparesely populated.

Also, there are places on each plane where other planes combine with them. These are called "leechings" if only matter crosses through, and "bubbles" if planar traits cross through. A leeching might be as simple as a chunk of earth floating out in, well, anywhere, and are most commonly found between elemental planes. Bubbles are substantially rarer, but can occur anywhere. They are essentially a pocket of one plane in the middle of another, so you might find a miniature material plane in the Plane of Fire, or a Sea from the Plane of Water in a cavern on the Plane of Earth. Some bubbles are unstable, and go back and forth between planes. Others don't.

Reading the Entries

Gravity: This describes the plane's gravity trait, and what it means for people on the plane. No matter what the gravity on the plane is, though, the planar medium usually behaves intuitively, as though it had a solid floor somewhere even though it doesn't. So the plane of air has lighter air rising atop heavier air, but the force on the air is as much levity as gravity.

Lighting: How the plane is lit, and what this means for people who need light, shadows, or whatnot. Also discusses general visibility conditions when light isn't the main problem.

Environment: This is the meat of the entry, and describes in a few words not just what it's like in general, but also what the places you want to visit are like.

Settlement: Who lives on the plane, and where on it they live.

Planar Capital: This lists the major planar metropolis on the plane. Each of the major elemental planes has one, as do some of the minor planes. These cities are big enough that you can find practically anything you desire in them, on a similar scale to Finality, although they deal in harder currency than souls: the infinite resources of the inner planes, or even the primordial chaos from which everything came. Most of the time, this metropolis is also where that element's genie empire puts its throne. Since the major power bloc on each elemental plane is the appropriate genie empire, that makes those throne sites into capitals of the entire plane. Sometimes, though, like on the Plane of Water, the genie capital is not in the major metropolis. In that case, both sites get mentioned, with an emphasis on the metropolis.

Note that every planar metropolis has portals in it. This may be an obvious statement, but it means a lot that isn't closely considered. These portals connects not just to outlying ouposts of the empire associated with the metropolis, but also to its trading partners: other planar metropoli. Because of this, even if two planar metropoli are at open war with eachother and have been for long enough that they don't have any portals between them, you can still go between them by way of neutral planar metropoli, without ever leaving a planar metropolis. In a very real sense, every planar metropolis is merely a part of a larger city. The implications of this will be explored more thouroughly in the Book of Civilization.

Sinks and Sources: A "sink" is a point on an elemental plane where planar material is being destroyed, or at least appears to be. Maybe they just redistrubte it. A "source" is the opposite, a point where planar material is either being created or being distributed to. Note that sinks and sources are not in balance with eachother, as sources also have to replace planar material that has been removed and used to build other worlds.

Special Site: A place you might want to visit or avoid, either a general category of place or a specific one. Each entry has two of these for planes that have a capital, and three for others.

Transportation Mode: This gives something people like to use to get around the plane. Usually its something you can use in other places, but sometimes it only works in one specific plane's unique environment.

Elemental Plane of Air

The Elemental Plane of Air is an endless expanse of varied gasses and vapors, mostly breathable air. They form into vague "clouds," which adhere to eachother much more closely than gasses do on the material, although clouds do still blend with eachother and mix. A cloud of normal air might be next to a cloud of sulphurous smoke, next to a cloud of lighter-than-air vapors. These clouds have a variety of temperatures, although most are only a bit above the freezing point of water. They are shot though with actual clouds of water vapor and ice, some of which are magically solid. The Plane of Air is self-contained; going far enough in any direction will leave you back where you started, although that would take a truly enormous amount of time and the plane's winds would likely catch you before then.

Gravity

It's the Elemental Plane of Air. Flying is supposed to be essential to go there. Then someone wrote "Subjective Directional Gravity" on its traits, so that flying would only let you turn faster than the round system allows you to with gravity. That's dumb and unjustifiable, and I refuse to write for that. The Elemental Plane of Air has light gravity (everything weighs half as much, falling damage dice are d4s, weapon ranges are doubled, unacclimated characters take -2 to Balance and Tumble checks and attack rolls, acclimated characters gain +2 to Jump checks), instead, and all flying spells and magic items have their durations doubled. The gravity is still bad for you, since you can just fall and keep going until you hit something. The air doesn't actually fall, though, because of the weirdness of physics needed to make the world at all intuitive.

Lighting

The Plane of Air is lit by a bunch of brightly glowing planar nodes to places like the Plane of Fire and Positive Energy Plane that drift around the plane. There are usually no shadows since there's nothing to cast them on, but the number of bright light sources are few enough that those with a surface to cast a shadow on usually do. The nodes are close enough together that the plane is usually lit to about the brightness of a late afternoon on a clear day (unless there's a cloud in the way), but far enough apart that there are seldom more than three contributing significant light to any given place.

Environment

The Elemental Plane of Air has a number of kinds of "islands" to floating in it. The most common are solid cloud formations, which are usually difficult terrain because of one's feet sinking into it, and are easy to swim or burrow into, although it is quite cold inside. They also have hazardous areas where the footing is only as good as Solid Fog, they tend to be fairly rough and also to have rough rises equivalent to Solid Fog or Fog Cloud rising from them and blowing along them. Constructions can be built on these formations, and ground can be paved or floors built to give more stable footing. Cloud Islands are almost invariably cold. Earth islands are substantially rarer, but also provide better footing; they take the form of rock formations and dirt hovering stably in midair. Water islands are similar, except that they take the form of bodies of water; constructions here usually float or are built underwater.

Because hot air still rises and cold air still sinks despite the Plane's oddity in gravity, winds still exist, and the Plane generates some truly awesome windstorms. Despite the lack of coriolis forces, bodies of air still have an inherent tendency to rotate on the Plane of Air, contributing to these storms. It also has prevailing wind patterns induced by magic; sometimes they are simple, leading from a site where the Plane of Fire leeches in to a site where the Plane of Cold leeches in, and sometimes they are more subtly induced by the Plane of Air itself.

The pressure on the plane varies, with most of it being comparable to breathable high altitudes on Earth. As such, creatures who live on the Plane of Air are always acclimated to high altitudes. Clouds' tendency to not mix allows them to persist against eachother even at different pressures. The largest clouds, which are usually made of breathable air, typically surround most of the other clouds.

Settlement

In addition to Mephits, Genies, and Elementals, the plane is populated by Arrowhawks, Belkers, Invisible Stalkers, and all manner of flying animal, in addition to air elemental versions of material planar creatures. Most of them don't need to eat, so little of the Plane's limited habitable areas are used for agriculture. A few potted or hanging gardens and fruit trees are used for luxury food and alcohol.

Most habitations are on cloud islands or rocky islands formed on Earth leechings. Some even float atop hovering "lakes" formed by Water leechings. A few settlements, though, simply sit as though on Immovable Rods, hovering in midair, or are even built as gigantic mobile craft. The Plane of Air, though, is very sparsely settled compared to the material; often, the next town is too far away to tell by sight alone that it is, indeed, a town and not just a brightly reflective or burning rock out in space.

Non-natives are also common settlers on the Plane of Air. Their biology gives them a lot more needs than natives have, and so they have to settle on chunks of arable land. Their settlements are usually built on Earth leechings, rather than on the more common cloud islands, since the former is far more likely to have arable land. Their populations are even sparser, and they stretch their dirt as far as they can use it, building most of their buildings out of wood (most of the new mass of a growing tree comes from the air, not the dirt) and planting everywhere crops will fit just to have enough crops to feed the town.

Djinn towns tend to be more relaxed. The main occupants are actually enormous net producers of food if they take as much as twelve seconds out of their day (twenty cubic feet of rice is a lot of food), so they don't actually dedicate effort to agriculture, and because of this can build on clouds, or waste dirt when building on earth. Typically each Djinni will have somewhere between ten and sixty servants, with most having around 20-30, but only a handful of Djinn will live in each town, each with their own palace.

Planar Capital: The Court of Ice and Steel

The leader of the Djinn rules from the Court of Ice and Steel, a mobile island or gigantic vessel made of ice and steel, with expansions built onto it of solidified clouds. His empire reaches as far as his vassals do, and his vassals reach far indeed. However, they are sparse, often visiting a town and moving on, leaving much of the plane out of his direct control. However, he can move the Court quickly, and wherever the Court goes is his center of power.

It's important to note that in older editions the leader of the Djinn was labelled a Caliph. This is not only historically inaccurate, but also insulting. See, the word "caliph" literally means "successor" and historically meant the successors to Muhammad as rulers of all of Islam. So, while it's cool to have all of the genies ruled by people with different vaguely middle-eastern titles, calling the leader of the Djinn a caliph only makes sense if the Djinn are muslim. Doing otherwise would be like setting up a scheme where one of the four rulers of the elements is called a Pope without having any mention of Christianity. Since writing real-world religions explicitly into the D&D world is emphatically not the goal of this project, the Djinn leader's title will be changed to sultan. Yes, that's the same as his archenemy, the Sultan of the Efreet, but, really, it's fine if they don't all have different titles, and matching two enemies together is the natural choice.

The Court of Ice and Steel proper is protected by steel-bound ice walls thick enough to be impossible to teleport through, despite the passages through them, although the cloud islands around it do not have this protection. The Court itself is small, by planar capital standards, about three miles long and one across at its widest point, in an ellipsoid shape. Inside the vessel is a large cavernous cavity, containing a huge, densely-packed city of Djinn and servants sculpted mostly out of cloudstuff, with the Sultan's palace near the front of the vessel, and containing the access to its control room, which is in an area of the palace none but a few select noble Djinn are allowed. Below and around it, however, are tight areas of ice caverns and steel walls, most of which are off-limits to travellers. Entering them deals damage as though travelling through a broken Wall of Ice; further damaging passages are common.

The vessel itself is obviously not of Djinn construction; the Djinn have little faculty with the magics of ice and even less with metals. Legends among the Djinn say that it was taken by their first sultan from an elemental lord of immense power, or perhaps even from a fiend. Rumors say that even now, whoever it was stolen from is plotting to get it back. It is known that the Court does come under attack and infiltration by daring pirates and raiders frequently, for such a heavily defended fortress.

Much of the capital is outside of Court proper, on the cloud islands and smaller vessels that surround it. These are likewise densely populated with Djinn, servants, and visitors. It is here that the majority of the city's population, and the vast majority of its links (at least, two-way links) to other planar metropoli can be found. Only some of the larger cloud islands are permanent parts of the city; much of the city joins for a time then separates from the city to go its separate way. It is not uncommon for a travelling captain, fearing pirates and hearing that the Court is going toward the same place as he is, even on a longer route, to join with the Court until he reaches his destination. This means that a significant amount of the city's population aren't just transients, but are actively in the middle of a voyage, and also means that entire districts of the city sometimes just up and leave. The Djinn aren't always keen on letting people with cool stuff keep to their original plans when those plans call for leaving, though. Even if a ship's captain and crew fully intend to leave, the Djinn might treat it as a permanent part of their city; which the ship actually is may never be decided until someone tries to take the ship away.

Sinks and Sources

Air Sinks take the form of huge vortices of winds, blowing into an invisible center with none blowing out. Because they're suspended in midair, they form as discs with the wind circling into a point, with concave cones of strong wind above and below, also blowing in. The only hazard of an Air Sink comes from its winds; the sink does not destroy anything but air and vapors, and never destroys creatures. A sink can last for weeks at a time.

Air sources are more transient, lasting for only a few hours. The gas it emits tends to be uniform, although not all are actually breatheable air; they have been known to emit poison gasses, lighter-than-air gasses, incendiary gasses, and so on frequently. Sources usually form on borders between existing clouds, creating a new cloud, although sometimes they form inside existing clouds, either creating a pocket cloud or simply changing the composition of the original.

Special Site: Coral Pool

The Coral Pool is one of a rare kind of site on the Elemental Plane of Air where it is interrupted with both Earth and Water. The Earth interruption takes the form of a stony spire, rising upward at about a 30' angle, with a water leeching around the bottom of it. The combination allows corals and similar life to grow, forming a vibrant aquatic ecosystem. A mob of Mephits makes their home there, lead by one with levels in Sorcerer. Additionally, an Arrowhawk nest can be found on the peak of the island. The Arrowhawk is on good terms with the Mephits that lair there, and warns the Mephits of intruders.

Special Site: Lighthouse Point

Lighthouse Point is a leeching of the Plane of Fire, where a giant shelf of burning embers and flames floats in the Plane of Air, burning brightly enough to illuminate for hundreds of miles. The shelf itself is about a mile long, half a mile wide, and several hundred feet thick, not counting the two-thousand-foot-high mountains that rise from the middle of the shelf. Dirigible docks hang off the edges in all directions. About a hundred feet beneath the shelf, there hangs a truly enormous inn complex connected to the docks by winding staircases, and an enormous covered market, with yet more docks. The inn is connected to the shelf by enormous steel chains, and is covered in a stone tile roof, to protect it from falling embers. This place, although it has precious little in the way of its own natural resources (at least that it is exploiting) is a major port for dirigibles going from one place to another. This is in part because the bright light gives it a good navigational beacon, in part because the heat causes a huge updraft to center around it, allowing ships to come in from below, lift up, and fly off along any wind, and in part because of the cunning of its mysterious proprietor.

Transportation Mode: Dirigible

Dirigibles work really well on the Plane of Air. Sources of lift gasses are available, and, in the light gravity, magical levitation sources work even better than normal, and the winds allow one to sail to nearly anywhere on-plane that strikes one's fancy. A few of the many types of dirigible are used on the Plane of Air:

• Dirigible Barge: A basket attached to either a stiff balloon of lift gasses or equipped with its own levitation magic. A Dirigible Barge mounts no sails, and is instead used by a flying creature as a transport of its possessions. Dirigible Barges cost 1 GP per 10 pounds of cargo room if lifted by gasses (but take about a cubic yard of balloon to carry this much), or 15 GP per pound if lifted by magic.
• Sailing Dirigible: A larger dirigible used to transport those who can't fly on their own. It mounts sails and is capable of tacking into the wind despite its weight and bulk. It costs 5 sp per pound of cargo room if lifted by gas, or 20 gp per pound if lifted by magic. One medium-sized creature's cabin generally takes up about a ton of cargo room, more if particularly luxurious. It can sail at up to the wind's speed in the direction it is going.
• Heavy Dirigible: A rigid-bodied dirigible used to transport large groups of mortals or large cargoes around the plane. It mounts sails and is capable of tacking into the wind, and many are capable of controlling the wind. It costs 1 gp per pound of cargo room if lifted by gas, or 30 gp per pound if lifted by magic (plus costs of wind control). It can sail at up to the wind's speed in the direction it is going.

Magical dirigibles are used for the greater security that not having a huge gas-filled target brings; as such, all dirigibles made for combat are magically supported. Dirigibles of any kind can be Wished for at no EXP cost; large dirigibles can be wished for in parts. On the matieral plane, magical dirigibles have half capacity due to the higher gravity. Due to the pressure differences, gas dirigibles still behave normally, provided sufficient gas can be found. The ability to tack into the wind on a dirigible is invariably magical.

Elemental Plane of Earth

The Elemental Plane of Earth is a self-contained solid mass of dust, sand, stone, and rock, shot through with seams of metal ore and gems. Unlike the other Elemental Planes, most of the plane is simply inaccessible, as teleportation is nearly useless through the plane of Earth. Unless you can find a tunnel, dig one yourself, or pass through another plane, such as the Ethereal, travel through the Plane of Earth is near-impossible, and regardless it is, compared to other planes, at a snail's pace. Contiguous masses of the same material on the Plane of Earth are called strata or seams, depending on shape.

Gravity

Gravity on the Plane of Earth is Heavy. In addition to its effects in the Dungeon Master's Guide, the heavy gravity trait makes moving anything over any distance harder, even moving oneself more tiring: time spent on the Plane of Earth counts double for forced marching, except for those acclimated to the Plane of Earth, and makes falls more deadly. Deadfalls and pit traps are a common form of deadly trap used on the Plane of Earth; when everything weighs twice as much and falls twice as fast, dropping the ceiling on someone often becomes the most effective way to kill them. For falling objects, double the object's weight before looking up falling damage, and change all falling damage dice (object or person) to d10s. Its effect on ranged attacks isn't as great as it could be, since most of the accessible Plane of Earth is tight passages or accessed only through burrowing. The whole mass falls in the same way one would expect a planet to, from the perspective of one within it (i.e., it doesn't).

Lighting

The Plane of Earth is pitch-dark naturally, although there are a number of glowing crystals that form naturally throughout the plane and are excavated to be set as lighting. Also, most of the plane is cramped enough that you can see the four walls with a simple Light spell, so the darkness doesn't really matter.

Environment

The Plane of Earth is the smallest, densest, and most stable of the Elemental Planes (that last part does not say much). It is made even smaller by having most of the plane be, unlike the Plane of Fire's blasted deserts or the Planes of Air and Water's empty voids, inaccessible solid rock or dirt. Still, the solid rock also makes the plane bigger, by forcing people to travel the paths between two points instead of simply teleporting. Every place of interest on the plane is a cavern, mine, or dungeon of some kind, and many of them are joined into complexes. These things are constantly being collapsed and reshaped by the plane's earthquakes.

Where other planes leak into the Plane of Earth, the Plane of Earth develops a number of special sites. Leechings of fire usually generate magma chambers, which form under intense pressure and often leak over quite a wide area. Leechings of Water and Air generate caves, including a few wider than any natural cavern on the Material Plane. These caves are surprisingly stable for their size and location in as unstable a place as an Elemental Plane, although the Plane of Earth's natural instability sometimes does collapse them. Note that these leechings aren't always the form of the element we all know and love. A water leeching can be freshwater, saltwater, aqua regia, or whatever, and an air leeching may well be poisonous or combustable.

Similarly to the clouds of the Plane of Air and the seas of the Plane of Water, the Plane of Earth is divided into regions with different compositions. These regions are called strata, and are arranged fairly randomly (geology doesn't work reliably on the Plane of Earth). Just like on the Material Plane, strata don't usually press into eachother and mix. Strata, and the boundaries between them, are shot through with thin seams of materials, sometimes valuable, sometimes not.

Settlement

Besides the Dao, Elementals, Mephits and all manner of strange beasts like Xorn and Thoqqua, the Plane is also inhabited by a number of burrowing material species. Their numbers, however, are kept down by the lack of food; the Plane of Earth is almost as hard as the Plane of Fire to farm on.

Because much of the Plane is difficult to access or even completely inaccessible from other parts of it, individual areas on the Plane of Earth can be much more independent from eachother than areas on nearly any other plane, including the Material, and even connected areas are far-flung from eachother. So the Plane of Earth is home to completely unique cultures even of the same creatures, and connected, large cultures are still very diverse. The Great Dismal Delve is the size of a continent, and you can't teleport across it, or scry across it, or anything, and neither can the Khan, which means that an outpost of Dao has to use more mundane means to send communications back to the Khan. The Delve itself is actually past the limit of what any individual empire can control on the Plane of Earth, and there really are areas of it that don't submit to the will of the Khan, and the Khan doesn't even know about all of them.

Every settlement is an excavation of some type, and the plane is subject to frequent earthquakes. Repairing the tunnels that connect excavations after earthquake damage is a frequent labor for those who live in such complexes, as the loss of their passages can mean being permanently cut off. The Great Dismal Delve is only the largest such tunnel complex; there are many others, some of which are connected and some arent; some of these even have Dao lords. The Dao in such complexes sometimes owe nominal fealty to the Khan, and sometimes don't; the Khan's agents have no way to enforce it, anyway.

A note has to be made about digging in the Plane of Earth. See, most of the underground areas in D&D, including the Great Dismal Delve and the Underdark, are being constantly expanded by digging. But excavation doesn't actually get rid of the rocks you're digging through, it just moves it around. Not only that, but a pile of mining debris has air in it, and so is actually bigger than it was before you dug it up. Mining from the surface actually makes huge piles of debris, and in the Great Dismal Delve there isn't actually room to put them, especially if you're trying to make it bigger. Digging on the Plane of Earth, then, is made possible by having disintegration furnaces; there are actually purpose-built pits on the Plane of Earth that disintegrate rock waste. These places aren't unique to the Plane of Earth, and mean that mining in D&D is substantially cleaner than it is in the real world.

Planar Capital: The Sevenfold Mazework, Great Dismal Delve

The Dao claim to rule the entire plane, but their power is centralized in the Great Dismal Delve, an enormous dungeon the size of a continent, which the DMG somehow managed to mention without mentioning the species of genie that rules it at all. The power center of the Great Dismal Delve is in the city known as the Sevenfold Mazework, home to the Khan of all Dao. Administration of the entire Delve flows out of the Sevenfold Mazework, in theory, and the Sevenfold Mazework is the major trade hub on the Plane. Because it's hard to travel on the Plane of Earth, most of that trade are people coming from off-plane to trade with the Dao.

The Sevenfold Mazework is called that because of its seven districts, although most of them are little-used. The most-populated mazework is the First Mazework, which forms a city of thousands of Dao and myriads of slaves. The Second Mazework is also populated, and serves as a nobles district. The remaining Mazeworks are little-populated, except for the Seventh, in the center of the city. The Seventh Mazework can only be traversed in gaseous form, and holds within it the Palace itself.

It's important to note that the Great Dismal Delve is actually really small as planar empires go. It's the size of a continent, which means that it's actualy comparable to some real-world historical empires, like the Romans (Europe) or the Mongols (Asia). Compared to the Efreeti or Djinn Sultanates, the Great Dismal Delve is tiny. It's important mostly because it's denser in both population and resources, and also because the plane it is on is much smaller.

Due to a bet made between the god of the Yakfolk and the Khan of the Dao, the entire Dao race nominally is enslaved by the Yakfolk. This is actually enforced over the Khan, and hence over all Dao in the Khan's control, but most of the Great Dismal Delve is little-enough controlled that the Dao there are essentially free.

Sinks and Sources

Most of the sinks and sources on the Plane of Earth are actually indistinguishable from eachother. See, the Plane of Earth has actual earthquakes on it, despite not having any magma source actually moving the plane. These earthquakes are caused by having two parts of the Plane of Earth, usually in different strata, being suddenly pulled together or pushed apart. When pulled together, whatever natural earth is in between them simply goes away; when pushed apart, something new forms in between them. Either way, as this whole process settles, an earthquake occurs.

Special Site: Truesilver Sands

The Elemental Plane of Earth is made up of all manner of earth, metal, and stone. Truesilver sands are a rare, and valuable, occurance on the Plane of Earth. They form when mithral ore is ground by the scouring action of rocks and sand, leaving fine-grained mithral ore mixed into a deposit of likewise-fine sand; one could almost swim, or drown, in it, and it is impossible to tunnel through. Because of the mithral ore's fine grain, it can be more easily smelted than larger chunks; the grinding action of the plane has left it finer than any artificial grinding can accomplish in a reasonable amount of time. Further, the plane has natural thermal events that may even smelt the mithral into tiny flakes, mixed in with the sands, leaving it pure for the gathering; it only needs to be washed out from the sands.

Special Site: Slime Tunnels

The Slime Tunnels are a unique intersection of elements on the Plane of Earth. First, they were a magma chamber and its associated vents. Afterwards, they flooded, and the obsidian walls were eroded and cracked away in places by erosion, by a Dao mining outpost, and by an earthquake, filling many parts of the chamber with mud, and, by the strange deep purple light of the glowing obsidian, plants grew, and died. Now it is home to all manner of oozes: Green Slime, Gelatinous Cubes, Black Puddings, and so on, making it immensely dangerous even to the prepared and wary. However, when the mining outpost was destroyed, treasures were left behind, including the treasured armor of the Dao overseer. Later expeditions have also gone in to try to reclaim that armor, and have left their own items overgrown by the green slime.

Transportation Mode: Tunnel Map

Navigation on the Plane of Earth is incredibly difficult. The tunnels systems are extensive, and, worse, three-dimensional, making the old standbys of maze navigation useless. Getting from any point A to any point B in a larger area than, say, a village or well-organized city (note that dao architecture is defensive in design, making them as navigationally difficult as blind tunnels for anyone but locals), then, takes an extremely detailed map and the ability to read it. A good tunnel map not only helps you find your course, but keeps you from getting lost and helps you find your way back if you do. Most tunnel maps are on large scrolls of specially-treated parchment, or thick tomes. However, because they must note incredibly detailed three-dimensional information on a two-dimensional sheet of parchment, their symbology is complex and arcane. Using one correctly takes a DC 15 Intelligence check for non-natives unfamiliar with the Plane of Earth, which can be retried only after getting lost due to the bad direction. A native or someone familiar with the Plane of Earth and tunnel geography can reduce the DC to 10, and need not make a check for a route they've used before.

Note that the tunnels change with new excavation, erosion, and collapse, so a tunnel map that is more than a year old is dangerously out of date. There are magical tunnel maps, which can have a number of features. They can be made substantially easier to use (DC 10 if unfamiliar or for the first check on a similar map for a native, auto-success if one has been successfully used before by one familiar with tunnel maps) by making them change the features they display to match what the user is looking for, or by displaying a three dimensional illusion of the complex, or both. They can be made to update themselves in areas they are brought through via Prying Eyes, Commune With Nature or similar spells. They can be compressed to a single sheet of metal by using stacked Secret Page effects, which also allows a user who knows their full set of command words (DC 15 Knowledge (the Planes) to understand the index, if it has one) to use them easily. All of these are available as minor magic items. Some extremely powerful dao forgo tunnel maps and instead use tunnel compasses, which are crystalline orbs filled with water in which floats a needle that points in the right direction, as a Find the Path spell that can only find places, sometimes only on the Plane of Earth (a major magic item).

Additionally, certain areas of the Great Dismal Delve have extensive networks of mine cart tracks. These are used to transport ore, debris, equipment, and even workers over long distances. If the tracks are kept repaired, then following them will invariably lead from some point A to some point B, and avoid caved-in areas besides. These tracks, though, rarely lead to where an adventurer will want to go.

Elemental Plane of Wood

The Elemental Plane of Wood was added as a bonus elemental plane in the back of the Manual of the Planes. Even though it doesn't actually fit into the elemental systems D&D is based on, or with the inner planes of previous editions of D&D, the third edition re-arrangement made room for it, and more than a few people like it. Plus it got a mention in the Dungeon Master's Guide for people making their own cosmologies.

So here's the Elemental Plane of Wood. It's a fairly habitable plane, as inner planes go, since the dominant theme there is plants and not, for instance, fire or death. The "ground" is made out of trees that grow out of eachother in arrangements that would make Escher's head spin, and is covered with every kind of plant life imaginable, growing and choking eachother out. Animal life is remarkably uncommon on the Plane of Wood, as its native elementals take a dim view of eating the plane's plant life. It's planar traits are remarkably similar to those of the Material plane, but spells that beneficially or neutrally affect plants (including Entangle) are extended and maximized.

Gravity

Gravity on the Plane of Wood is normal in strength, but strange in direction; it points toward the largest nearby trunk or limb when outside. When inside, it generally bends slowly toward the originating trunk (in a limb) or the origin of the trunk (in a trunk). Trees grow out of eachother at odd angles, due to the strangeness of the gravity. Gravity near the bottoms of trees and the bases of limbs, though, generally is unaffected, sometimes for as much as 20 feet along the tree or limb. Small trees (less than about one or two hundred feet tall) do not generate their own gravity. Because of the way gravity works, many of the plane's trees actually have their thickest points well away from their base.

Lighting

The Plane of Wood is lit by a light source that always appears to be just through the next several layers of leaves. The entire plane is dim, but bright enough to see perfectly well by during the day. This light source migrates, brightens, and dims, on roughly a 24-hour cycle, giving the plane "night" and "day." Days are much longer than nights on the Plane of Wood, but during the nights it's as dark as any night in a deep forest on the Material. A few parts of the trunks of larger trees also have luminescent nodules, which provide a constant source of illumination for other plants.

Environment

The Plane of Wood is made of trees, some larger than anything on the material plane, growing out of eachother. Because of the oddities of how gravity works, falling isn't actually a hazard unless you get away from the branches. It has all the plant life of thousands of material ecosystems, from forests to grasslands on the side of tree trunks, and very little of the animal life. Bees are the most common animals on the Plane of Wood, as they are considered by the plants to be harmless. The bees on the plane of wood are subtly altered by the plane, however, being more integrated into the plane's collective conciousness.

All plant life on the Plane of Wood is, in a sense, a single entity, albeit one constantly struggling with itself. All plants, plant creatures, and native elementals are aware of the presence and general emotional state (but not location) of all other plants, plant creatures, and native elementals within 200 feet, except for those that are specifically hiding. This awareness is not just knowledge, but feeling; feeling another's calm makes the plant calm, and anothers' distress is likewise echoed. Certain bee hives are also able to share in this awareness, but only at a hive level (individual bees do not, but the hive does). These bees will emerge to sting creatures they catch harming their plants. Harvesting anything more than ripe disposable fruit from plants causes them distress, bringing down the wrath of the plane on the interloper. But the plane doesn't have too long of a memory, or much ability to track people; if you're able to get away from where you did your damage without being seen, you're safe until you harm the plants again.

The Plane of Wood is greatly different from the other elemental planes. While the other elemental planes are simply random arrangements of elemental matter, the plane of wood is ordered on the smallest scale, as all living things are. Exactly what this means depends on your interpretations of the elemental planes and thermodynamics. If the multiverse is running down, then the Plane of Wood is either far from running down or is using other planes for fuel. If the multiverse is growing, then the Plane of Wood is one of the fastest-growing parts of the inner planes. Because of its complexity, wood might not even be a proper element, depending on what being an elemental plane means.

Every kind of plant creature, and even fungal creatures, native to the Material Plane has some representatives on the Plane of Wood. Even oozes grow here, although they are all either not harmful to plant life or live only in areas of blight and disease. Some vermin, such as giant ants and termites, also make their homes within the trees of the Plane of Wood, finding themselves in a constant war with the native plant life to carve out a settlement. Likewise, there are herbivorous scavengers that only eat dead plants. There are many tunnel complexes in the plane that were once giant ant colonies before being exterminated by the plants, or that starved after having killed the land. Predators are also accepted by the planar natives, but rare across most of the plane because there's nothing for them to eat.

If you stay still on the Plane of Wood, you will be overgrown. This takes too long for anyone to really notice while awake, but if you stay in one place for about four hours you become entangled. After about eight or nine hours you can't generally brush your way out and have to cut yourself out, which the plane tends to frown upon. Burial takes several days, and even then, you're mostly buried in vines and branches. Despite what travellers tales may say, even if you stay still for years you are unlikely to actually get absorbed into a tree.

Other elements leech in to the Plane of Wood on occasion. Water leechings form huge lakes in the cracks in the bark of larger trees, although most eventually seep into the tree, causing it to flourish if fresh or creating an area of blight if salty. Fire leechings are also noticeable, as they form massive brushfires that run along the plane, sometimes even scorching through the thick ground bark and burning entire limbs away. Earth leechings are quickly overgrown and integrated into the plane. The most commonly noticeable, though, are positive vortices, regions that grow thick, augmented by the Minor Positive-Dominant trait; some such areas also glow brightly, although the overgrowth in and around them usually masks this.

The Plane of Wood has regions where most of the native wood and plant creatures are dead, called "blights" or "scars." These tend to be the safest for non-natives, since you can usually get away with farming in them, if you can get the plants to take. Sometimes the decaying wood provides a fertile ground for new life, while other times whatever killed the last plant is still waiting for new plants. Revitalized blights, though, are often quickly retaken by the plane.

Settlement

Most of the Plane of Wood is unsettled. The plane has no native Genies or other major civilized life, although some fey are native (but not enough to build a town), so all settlement is of non-native species. Their reasons for coming vary from settlement to settlement and individual to individual. Settlements are seldom made of wood, as the elementals take a dim view of cutting it, although some are made of still-living wood. Because of the way gravity works, settlements spread across multiple large branches are connected by ladders, rather than bridges, and gravity suddenly reversing on a ladder can be upsetting for newcomers (and their stomachs).

Because travel through the wilderness is slow, and gathering food is difficult, no two settlements on the Plane of Wood are the same. One town might be a group of elven exiles, and the next over could be a goblin fortress. One might be a circle of druids, bargaining with the plants for their food, while another has a farm and castle on a blight, and a third group can be nomads, on the run from the plane's wrath.

Planar Capital

None. There are no plane-spanning empires on the Plane of Wood.

Sinks and Sources

The plants on the Plane of Wood grow constantly, and are constantly killed by choking, rot, or attack. Nearly the entire plane is a source for its material, and sinks show quite frequently in dead plants, and, especially, in blights, although they make up for this by working much faster, rotting away the planar material.

Special Site: Prosper

Prosper is a village inhabited by dwarves in an abandoned giant ant colony. Having given up on mining due to incessent elemental attacks, they instead now tend the plants on the surface above their colony and fungi deep beneath, with a substantial contingent of druids to advise them on when the time to harvest is. Prosper is entirely self-sufficient, and is welcoming to travellers, even those hounded by the natives of the plane. They will allow such travellers to rest, for a time, and teach them the ways of the wood.

They retain what they can remember of their material planar ancestors' culture. Their ledgers are sparser, as good materials to write on long-term are not given as frequently by the plane of wood as can be taken from the material. Nonetheless, they still retain many dwarven traditional songs (some of which have mutated to their new homes, or changed in purpose; many mining songs, for instance, have become festival songs), and they also maintain variations on dwarven cooking and brewing adapted to the newly available foods.

Special Site: Amber Bog

Amber Bog is a site where a more acidic part of the Plane of Water once leeched into the plane and burned through the bark over the ground. Now the remnants of the acid mix with resin from the plane and form a thick, gooey bog hundreds of feet deep in places. The deepest parts of the bog have some large chunks of amber within them, but the entire bog is guarded jealously by shambling mounds and similar plant creatures. Still other parts of the depths have resin rising out of the plants, never healed after all this time, or possibly being constantly reopened. The amber here also preserves a number of species of insect with uses in magical research, and the amber itself may also have unique properties. The ground is difficult terrain at best, and liquid, or even sticky liquid, at worst, making travel difficult.

Special Site: Sapline

The Plane of Wood is truly enormous, and the nourishment that they draw has to come from somewhere, which is usually quite far from where it is ultimately consumed. Saplines are the fastest way such nourisment is transmitted, and, as they rely on the plane's gravity traits, have no counterpart in material plants. They are massive tunnels; those smaller than five feet across are not counted as true saplines, and they range up to twenty or even thirty feet in diameter. All saplines have null gravity, despite the gravity outside of them, and draw the sap through them via an unknown force. They are all found deep inside their constituent trees, although parasite plants often send roots down to reach them. The saplines narrow and end in their originating plants' root systems, or sometimes in portals to other planes (such as Earth), and at the tops of their originating plants, where there is no more sap to distribute.

Sap is sticky and slow enough that all creatures in sap are counted as entangled. Other than that, it behaves almost exactly like being underwater. There is not much oxygen in this sap, so being able to breathe water nonmagically doesn't help. Creatures that get out of the sap are entangled until they can remove it.