[whswhs]

I would suggest that the dreamworld is comparable to the astral realm, Yetzirah, in GURPS Cabal.

One of my conceits about the three realms was that each was governed primarily by a different magical law and a different type of signs. The law for the material plane is Contagion, which operates by things coming in contact with each other; this goes with indices, or signs of things that cause them, as smoke is a sign of fire. The law for the astral plane is Similarity, which operates by things resembling each other; this goes with icons, or signs of things that resemble them, as a photograph is a sign of its subject. The law for the mythic plane is Names, which operates by things being identical to their names; this goes with symbols, or conventional signs.

It occurred to me that each of these could be associated with a metric. The metric for causality is the familiar one of geometric interval and lightlike lines. The metric for symbols is the number of changes needed to turn one symbol string into another—almost a binary metric, or at any rate a digital one (there was an article or forum post a long time ago that defined characterizations for the decans in terms of a 3x3x2x2 structure, which I took as a metric for the mythic plane). But the metric for resemblance is one of things that look alike being close together. So if you can morph an image of A into an image of B you can navigate from A to B. This would be rather like the way Amberites walk through Shadow, actually. I think that makes sense for dreams, where one thing can change into another.

Bill Stoddard