Planes, Worlds and Planar Travel - Midkemia Online Online Help

12.2 Planes, Worlds and Planar Travel

While it is theorized that there are numerous planes of existence in the
Midkemian universe, it has never been a proven fact. However, the
discovery of Rifts during the Riftwar has led to an awareness that many
worlds exist in the universe - far beyond the reach of any means of
conventional travel.

With Rifts, travel between these distant worlds is possible (and even
travel within the same world). However, with the destruction of the
Great Rift at the end of the Riftwar, no permanent Rifts are currently
in existence on Midkemia -- and thus travel to other worlds, including
Kelewan, has been rendered impossible.