Realmatic Theory refers to the structure of the Cosmere. There are three realms: Physical, Spiritual, and Cognitive.
“I have come to see that each power has three aspects: a physical one, which can be seen in the creations made by Ruin and Preservation; a spiritual one in the unseen energy that permeates all of the world; and a cognitive one in the minds which controlled that energy.”
“All things exist in three Realms, Gaotona. Physical, Cognitive, Spiritual. The Physical is what we feel, what is before us. The Cognitive is how an object is viewed and how it views itself. The Spiritual Realm contains an object’s soul— its essence— as well as the ways it is connected to the things and people around it.”
 Physical Realm
All of Brandon's published works take place almost exclusively in the Physical Realm. Of the three realms, it is the most readily understood, as it behaves in much the same way as our universe does.
 Spiritual Realm
All that is currently known about the Spiritual Realm is that it is the site of the afterlife in the Cosmere (at least for people from Scadrial, and likely for the rest of the Cosmere as well), and that when they are not in use, Shardblades are stored there. It can also be supposed that the Dor and BioChroma are related to the Spiritual Realm.
 Cognitive Realm
Extremely little is known about the Cognitive Realm. Brandon tends to be rather close-lipped on the subject.
|Shards||Cultivation · Devotion · Dominion · Endowment · Honor · Odium · Preservation · Ruin · Bavadin's Shard · Survival Shard|
|Shardworlds||Nalthis · Roshar · Sel · Scadrial · Taldain · Yolen|
|Terms||Adonalsium · Sliver · Splinter · Realmatic Theory · Intent · Focus · Investiture · Shardpool · Spiritweb|
|Other||Hoid · Seventeenth Shard · Chronology · Shattering · Worldhopping|