Dream Not of Other Worlds -- A Selection of Portable Demiplanes

...Heav'n is for thee too high
To know what passes there; be lowlie wise:
Think onely what concernes thee and thy being;
Dream not of other Worlds, what Creatures there
Live, in what state, condition or degree...
-- John Milton, Paradise Lost, Book VIII

From the TNG episode “Remember Me"

One of my favorite things about the assumed setting of D&D is the potential for planar travel. And one of my favorite aspects of that has long been the idea of demiplanes -- small universes of limited scope that can pretty much range from “big but not infinite" to “comically small". They're often deeply weird, or have some specific purpose that almost-but-doesn't-quite make sense in our Earth logic. Which is, of course, what makes them fun.

Here, I'm presenting a handful of demiplanes that can be accessed through portable magical items -- making them, essentially, “pocket dimensions" in every sense. On that note, let's start with the:

Pocket Necropolis

Source.

The Pocket Necropolis can be accessed through a small stone talisman that resembles an ancient tomb -- which, appropriately, is small enough to fit in one's pocket. Uttering a command word allows one to enter the Necropolis, where they will find... a large, dusty, stone chamber. There are multiple exits from this chamber, however, and each of those leads to long, branching corridors lined with heavy stone doors, each of which is inscribed with a name. (All inscriptions, engravings, &c. produced by the Pocket Necropolis appear in the native language and writing system of the reader.)

Each of the stone doors leads to a tomb, in which one will find a stone sarcophagus and associated burial items.¹ If someone is so rude as to open the sarcophagus, they will find that the body within is preserved under the effects of a permanent gentle repose. On the sarcophagus is engraved an epitaph, giving a general (if somewhat exaggeratedly positive) idea of who is interred there, and all around the room in shelves and niches are items of personal significance to the deceased. Examination will reveal that many -- if not all -- of these items are clever counterfeits, created by the Necropolis because it doesn't have access to the real thing. It should be noted that the Necropolis's counterfeiting ability does not extend to enchantments, but is otherwise extremely thorough -- if it makes a copy of a book, the entire text will be accurately reproduced. If that book was supposed to be magic, well, it's just not. It should also be noticed that the Necropolis will be pleased if you go out and find that particular copy of that book for it so the tomb can be better stocked. That kind of leads into the next relevant item -- the Necropolis is aware of people wandering about inside of it, and has opinions about them, which it expresses via its internal guardians.

Source.

The Necropolis's internal guardians can take the form of any type of undead, with the same stats as they would ordinarily have, with only one exception -- they are under the control of the Necropolis, which can speak through them. In the case of intelligent undead -- spectres are a particular favorite of the Necropolis -- they still possess the intelligence and personality of whoever they “were" in life, but obey the orders of the Necropolis unquestioningly. These guardians are always patterned after individuals that the Necropolis has entombed, but, again, this is a matter of clever counterfeit. The Necropolis is of the opinion that it is extremely disrespectful to raise the dead, as undead or as living beings, and would never undermine itself by doing so -- the “undead" internal guardians are created out of whole cloth.

The Necropolis is pleased if you respect its tombs. It wants you to leave the grave goods where they are and not mess with the bodies in any way. As mentioned above, it likes it when you help stock the tombs as well. It will become violently displeased with you if you make a habit of stealing the grave goods or dare to raise or animate any of the tombs' occupants. The Necropolis is also pleased when you bring it more bodies.

If you leave any dead body unattended in the entrance chamber, it will vanish within 24 hours, when the Necropolis takes it and makes a new tomb for it. It unerringly knows enough about the dead to engrave the epitaph and stock the tomb; this can function as an information-gathering device for the PCs, with the caveat that it's really difficult to find the new tombs. The Necropolis, you see, does not have empty tombs you can stake out; when it needs to inter a new body, one of its many branching corridors grows slightly longer and a new tomb appears, in whatever spot seems like the best place for that person to be -- the Necropolis has a system for organizing its tombs, but what that might be is largely opaque. As a result of this mechanism, the Necropolis is huge and has a fairly non-intuitive layout.

Source.

The Necropolis generally only provides tombs for sapient beings. If you leave bodies of creatures with an Intelligence of 5 or lower in the Necropolis, it starts getting picky with how it treats them. They still get a tomb if the Necropolis sees them as exceptional in some way, though the odds of that go down as their Int score decreases -- a griffon (Int 5) has a pretty good chance of being assigned its own tomb, but a lizard (Int 1) had better be one heck of an impressive lizard. If the body doesn't meet the Necropolis's standards in this respect, instead of getting an individual tomb, it will appear in one of the Necropolis's storerooms. These are large chambers in which the walls are covered in niches of various sizes, each of which holds the body of an animal, cleaned, repaired, and under the effects of gentle repose. There are epitaphs carved over each niche, but they are very brief -- a name, if the creature had one, and a one-sentence description of their life & death.

You can theoretically use the Necropolis for storage, like a bag of holding, but there are some caveats. If you leave something in there that has personal significance to one of the bodies interred -- which becomes pretty likely if you start tossing in bodies of creatures you killed and/or looted -- the Necropolis will take it to be part of that tomb's collection of grave goods, and will get upset if you try to take it back. Second, and perhaps more worrying, is the fact that you're not the only people with access to the Necropolis.

Parties who take the time to explore the Necropolis fully will eventually discover several other empty chambers like the one they started in, scattered randomly about the complex. Each of these is an entrance chamber connected to another stone talisman just like the one the PCs have. There are dozens of these talismans, spread out over incredible distances, and many of them are probably in use. So one of the dangers with using the Necropolis as storage or as a safe place to rest is that you're not alone in there. And if some of the other people in there are better about following the Necropolis's rules, it might take sides.

You know, one of these.
Source.

Nackleshire²

The item that allows you to connect to Nackleshire is a mottled, off-white sphere that kind of resembles one of those Himalayan salt lamps you see everywhere these days. Examining it closely will reveal very small runes engraved into its surface; if any of the PCs can read them, they provide the command word to activate the item.

Once a day, the Nackleshire item allows the user to summon a salt mephit, who will remain for one hour before vanishing. The mephit will obey your orders, but may or may not be happy about it; if the PCs order the mephit to do something that is overtly dangerous or against the mephit's personal moral code, the GM is encouraged to resolve this through giving the mephit a Will save to resist, or making opposed Charisma checks, or similar. Over time, as the PCs use the item, they will find that Nackleshire contains exactly twenty mephits with differing skills and personalities³, and they get a random one each time. Whenever a mephit vanishes or is killed, they reform in Nackleshire, where apparently they have some kind of social life -- they tend to report back on their experiences, talk to each other, and form opinions on the PCs. If, over a long period of time, they feel that the PCs are treating them well and showing adequate respect, they may unlock some of the item's other abilities.

From the 3rd edition DMG.

The second ability, which requires a different command word and the permission of the mephits, is a variant of the classic magic item Daern's Instant Fortress. The differences are largely aesthetic: the tower and its interior furnishings have the same mottled, off-white appearance as the sphere. There are a couple functional differences, however. First, you can only use it once a day⁴, and it dematerializes after eight hours. Second, the tower is not expanding from a compacted state, but being shifted over from a demiplane. This has a couple obvious results: it doesn't deal bludgeoning damage as it expands, but just appears around the person using it. Also, when you dismiss it, you can leave inanimate objects in there without having to worry about them getting trash-compacted. The PCs may well find furnishings, books, &c. left in there by previous owners. Third, it comes with a butler; one of the twenty mephits in Nackleshire is employed as the butler and caretaker of the tower, and will happily accommodate the needs of the PCs. He can even summon them some food, if they need it, though anything he summons tends to be just a little bit too salty.

The third and final ability allows the PCs to enter Nackleshire themselves. Like the second ability, you can only use it if the mephits like you enough to give you that privilege. Once per day, the owner of the item can open a portal to Nackleshire. (There is no limit on how often you can open a portal back out.) In Nackleshire, there really isn't much to see; there's the tower, and outside of that, the plane is a lot like living in a snow globe filled with salt and friendly mephits. The benefit of using this ability, of course, is nothing to do with the scenery -- it's a more-or-less unassailable refuge, because even if someone would think to look for you in some random demiplane, getting there would be quite difficult. (And even if someone does manage to plane shift in, you have a fortress and a platoon of mephit allies.

Source.

Wandering Oubliette

This is an item you don't so much own as encounter. It's a portable hole that's gotten too big for its britches, probably as the result of someone trying to improve the original item. The Oubliette wanders, autonomously, seeking out creatures to swallow; it has an animal-level intelligence, and can enact some basic hunting strategies, such as sticking to dark, enclosed spaces so it can blend in and ambush prey. It manifests as an oversized portable hole, more than ten feet in diameter and some hundred feet deep.

Inside the Wandering Oubliette, you will discover circular walls of smoothly-polished stone, that curve towards the smaller opening at the top, rather like the inside of a bottle. It is intentionally difficult to climb out, and the floor is likely littered with the remains of the Wandering Oubliette's previous prey. This is the entirety of the little extradimensional space in which you have been entrapped. Lucky for you, you probably don't have to worry about running out of air -- the Wandering Oubliette rarely bothers to fold itself up. Unluckily for you, it really does wander; through some unidentified mechanism, the Oubliette seems able to teleport from one dark, enclosed space to another on a fairly regular basis. So if you do manage to climb out, you may find yourself in a different place entirely.

Ebu-Gogo Talismans

Hundreds of millennia ago, another people lived in the land that we now occupy. But, for one reason or another, they were pushed out, and the people who live here now supplanted them. There are virtually no remaining records of these people, except in abstracted legends about predecessor races, which refer to them as Ebu-gogo. When the Ebu-gogo recognized that they were losing the long struggle for their land, they turned to their shamans, who were said to possess strange powers beyond what any modern cleric can achieve. These shamans built refuges, demiplanes just big enough to support their tribes, and the Ebu-gogo fled into them. The entrances to these demiplanes were keyed to small, carved talismans that were enchanted to survive the millennia and then hidden -- so that, if any of the Ebu-gogo needed to leave and return, they would be able to use the talismans to do so.

Source.

And, of course, they do occasionally come and go. Sometimes, for one reason or another, food is scarce in their demiplane one year -- it's rare, but it happens -- and a raiding party needs to pop out and loot some supplies from the outside world. Sometimes a younger member of the tribe gets curious, wants to see what it's like outside, and goes out exploring. Sometimes, the tribe is so enraged by a member's behavior that they are exiled. Sometimes, there's an inbreeding issue and someone needs to go find & court members of another tribe. And sometimes, there's a matter of the Ebu-gogo's unique version of population pressure.

When the demiplanes were originally built, the shamans made them exactly big enough to sustain a nomadic lifestyle for their tribe. As long as the population of the tribe never grew beyond where it currently was (usually between 100 and 200), they should be able to live off the land indefinitely. And to make sure that such a thing never came to pass, part of the way the demiplanes function is that they will not allow new children to be born if it would increase the population past the original carrying capacity of the demiplane. Usually, the Ebu-gogo can work with that, and when they bump up against the population cap, a sort of automatic birth control switches on. However, sometimes, due to unfortunate timing, an Ebu-gogo woman finds herself already pregnant when they reach the population cap, and is then stuck with a child she cannot give birth to unless someone else dies. Since an indefinite pregnancy would be very unpleasant, a solution must be found -- and that solution is generally for someone to volunteer to leave to make room for the baby. (If nobody volunteers, the mother will probably end up leaving.)

Ebu-gogo, or rather, an artist's
recreation of Homo floresiensis.
Source.

The other side of Ebu-gogo population caps is that nobody can enter the demiplane if it is at its maximum population. This means that the aforementioned unfortunate exiles are usually trapped outside permanently, and are forced to find a way to live in a world completely different from the one they and their ancestors spent their entire lives in. It also means that, even if an outsider finds one of the talismans, there's a chance that it just doesn't work -- the demiplane might be full and nobody can get in even if they know how to work it.

The Ebu-gogo themselves possess a striking appearance. They are small -- about the same stature as halflings -- dark-complected, and very hairy. They have unusually long limbs for their size, and notably large mouths. They're generally decent folks, assuming you're speaking to someone who came out of the demiplane voluntarily and not an exiled criminal. However, they tend to be a little odd by human standards -- after all, if you're talking to one, one of the two of you is probably a recent immigrant to another reality. Their longer legs and arms make them excellent hunters, able to run at impressive speeds for their size and throw a spear with terrifying strength.

Source.

The reason they seem a little odd, other than normal degrees of cultural divergence, is because where they come from, reality works differently. When the ancient shamans built the demiplanes to which they retreated, they modeled them after the tribe's beliefs, teachings, and understanding of the world. If they believed that the world was carried on the back of a turtle, that's what the world was really like inside the demiplane. If they believed the shaman had to propitiate the sun to make it rise each morning, then the shaman really had to do that or they'd be stuck in the dark. The whole of their miniature world operates on a different logic than ours, and after living there for uncounted generations, that's their normal.

---

1 The size of the tomb chamber scales roughly with the size of the person interred there -- a human would get a chamber roughly ten feet to a side, but a storm giant's chamber would be thirty-five feet to a side.^↩
2 I posted this idea on the Giant in the Playground forums a while back, and it subsequently received some limited use in a campaign log by another GM here.^↩
3 GMs are encouraged to note up a list of different mephits with divergent personalities and capabilities for this purpose.^↩
4 GMs whose campaigns might be broken by allowing the players a refuge every night are encouraged to reduce this to once a week.^↩