Transitive Planes

"Transitive Planes" was a term used by the old D&D cosmology to describe the collection of planes that joined other planes. Originally, this consisted of the Ethereal and Astral planes only, with the Plane of Shadow/Shadowfell and Feywild being added to the list later.

Personally, I'm not a big fan of the term, but there's nothing wrong with the concept - after all, something needs to join one plane to another. However, I'm also not absolutely sold on the set of transitive planes used by D&D - some of them are fine, some need a little tweak, and there's one I would like to add.

That being the case, here are the five transitive planes that I have in mind to use:

• Astral Sea: The biggest of the transitive planes, this is a timeless, airless void that links all the planes. Travel is reasonably easy, but almost nobody lives here. The major landmark in the Astral Sea, other than the permanent gates to the individual planes themselves, are the Dead Gods - the petrified remains of deities that once were and now are not.
• The Shadowfell: Yeah, that's a better name that "the plane of shadows". This is a darkened mirror of the world, full of entropy and decay. Not a nice place to visit, and even less nice to live, it is a haunt of necromancers and the undead.
• Wonderland: As in "Alice in...". This is the replacement for the Feywild, and is a wild and nonsensical place, albeit one with its own twisted logic (and a logic that cannot be denied - the rules may not make sense, but those are the rules and you must respect their authoritah). Wonderland is the home of the Seelie and Unseelie Courts of the Fey, led by the White Queen and the Red Queen.
• The Land Beyond the Mirror: Beloved of seers and diviners, this is the realm that can be seen by those who stare too deeply into mirrors. Travel in the Lane Beyond the Mirror is dangerous, because it is a reflection of all those who venture there.
• The Great Web: Unique amongst the planes for being a creation of mortals, the Great Web is exactly what the name implies - a giant web of strands leading up, down, and sideways to any plane you choose to investigate. The main problem is that the Web is unmapped, and indeed defies all attempts to map it. The wise therefore venture there only after first plotting their journey. Though perhaps that is not the greatest problem - after all, does a web not imply spiders...?

It's worth noting that this structure does not allow any room for an Ethereal Plane. Instead, I'm going to take the view that being 'ethereal' is a condition that some creatures may possess, but that does not denote movement to any other plane.