's The Heritage of Humankind
system, there are infinite parallel universes that differ from each other very little or very much. Extradimensional space
(EDS) is what is between these universes, separating them from each other. That makes EDS very special, in one way chaotic and unnatural.
Technically EDS could be the same as Cross'd Roads.
Technically, EDS has an infinite amount of dimensions (while the real universes or interdimensional spaces
, IDSs, have some fixed amount that's usually less than 15, but hard to tell) that may or may not interact with each other. There are places in EDS that are completely incomprehensible to a creature used to three spatial dimensions and one time dimension.
2. Changing spaces
Technically it should not be possible to shift from an IDS to EDS, but evidently it has happened and caused a whole lot of issues. Shifting from one IDS to another is still not possible; one always has to travel through EDS, no matter how briefly. The way of transport from IDSs to EDS or the other way around is via dimensional rifts in an IDS. If a dimensional rift is initiated in EDS, it just mucks up EDS a bit more and has no effect in any IDS.
The main way in which these dimensional rifts are born in IDSs is that a person with an ability to create them is born (unsurprisingly, it's usually the same person) and the person then creates one. Most often, the person has enough control over it to not drive the whole planet into chaos, but sometimes the whole universe gets destroyed due to an uncontrolled rift. In EDS, it might or might not have drastic effect. However, the destruction of an IDS is not a big thing in EDS, except possibly for the place (if it's a place at all) in EDS where the rift initially appeared, provided it did not relocate.
Due to the rifts from an IDS to EDS, interdimensional creatures end up in EDS. Some of the few interdimensional people who have managed to learn how to survive in EDS have created a loose organization whose purpose is to keep IDSs separate from EDS. It's generally known as Extradimensional Space-Rangers
Most often fulfilling the purpose of the organization means the killing of people with the ability to created dimensional rifts and the returning of stray interdimensional creatures to their own IDSs. However, to kill a person who is able to create rifts, the rift has to be already created, since otherwise it's impossible to get into that particular IDS in the first place.
The members of the organization (also called extradimensional space-rangers) don't really follow any set standard of conduct, code or morals – the only thing they actually agree to is respecting and helping other extradimensional space-rangers.
Basically all extradimensional space-rangers are given equipment and training with which they're able to efficiently achieve the purpose of their organization.
- IDS scanner: way to figure out the original IDS of an interdimensional creature.
- EDS scanner: way to get the identification data (ID) of a specific spot in EDS.
- Programmable hole: quick way to move virtually anywhere in EDS, uses IDs as a destination.
- Pocket hole: personal living space.
- Media hole: depending on the viewer, a television or a crystal ball that views a certain part of EDS according to its ID.
- E/IDS calibrator: external device to stabilize the hole and scanner in unstable environments as well as a way to modify the hole to create a controlled rift from an IDS into EDS or vice versa.
- Weapons: for basic self-defense and the killing of people with the innate ability to create dimensional rifts.
4. EDS quirks
EDS IDs can be scanned from the "location" of any spot in EDS by an EDS scanner. Also creatures and such have their own IDs. Telepaths can figure out the IDs of thinking creatures by a telepathical scan, and they can also figure out the IDs of places the creature has been to if the creature can focus on the memories of the place, even if the creature had no clue whatsoever about any kind of IDs.
See also: Kim the extradimensional spacetraveler