A planar stack is a collection of tightly grouped planes, usually holding strong connections to each other.
A planar stack consists of a series of planes, clumped together, sometimes in a stack (like in Alaria). While the laws of nature, magic, and physics differ from one stack to the next, their overarching structure are generally the same. As one travels from the cosmos to a planar stack, to a plane, the number of dimensions steadily decrease.
Major Planar Stacks
The cosmos contains several major planar stacks, of which Alaria is the primary focus of this almanac. Other major stacks include Epyphiozath and Instruxofinum.
Other Known Stacks
Beyond the major stacks, there are other known planar stacks that have been visited or observed: Glyssen, Klokas, Narglon, and Lanthornia, the neighbour whose eruption rained Aether and Lanthornium down onto Alaria.