Mystara Dimensions (WotI)
by Håvard
Some people asked me where the Dimension of Nightmares fit into my planar maps. This is how I see it.
Note: This diagram uses the WotI definition of Dimensions. The Frank Mentzer interpretation of dimensions is very different.
Another bit of controversy in this diagram is that I included the Great Wheel. This is indeed the Planescape multiverse or the AD&D Multiverse as it was called before that. This is where you find the Forgotten Realms, Dragonlance, Greyhawk and the other worlds.
Is this just a fan interpretation? Well, several BECMI sources actually refer to the AD&D Multiverse. The D&D Rules Cyclopedia talks about "Reality Shifts", where Mystara can be brought into the AD&D Multiverse. Long before that Frank Mentzer and Gary Gygax wrote AC4 the Book of Marvelous Magic included "Alternate World Gates", one leading to the AD&D Universe. Others lead to other TSR Game lines at the time like Dawn Patrol, Gamma World and Gang Busters. I actually think these last three could be the same Dimension at different moments in the timeline. Perhaps it is even just LaTerre/The Dimension of Myth.
The Dimension of Myth can also be accessed via Yggdrasil, so it could be linked fairly closely to Mystara's cosmology.
The one Dimension I did not include is the Dimension of the Galactic Federation. Although WotI does talk of the world of the FSS Beagle as from a different reality, they never use the word Dimension and it is not included in the writeup of Dimensions in Codex I of that boxed set. Personally I much prefer the Galactic Federation, just like Old Alphatia as different parts of Mystara's Galaxy. This is very much in line with how that Galaxy was described in the Gold Box.