Realmatic Theory refers to the structure of the Cosmere. There are three Realms: Physical, Cognitive, and Spiritual.
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. ”I have come to see that each power has three aspects: a physical one, which can be seen in the creations made by
”Giving water to the tiny plant causes a chain reaction of sudden growth, energy, and Realmic transition. Certain people can control this reaction, using the water from their own bodies to forge a brief cognitive bond. They can draw Investiture (in very small amounts) directly from the Spiritual Realm, and use that to control the sand.
”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.
”All things exist in three realms, Dalinar. The Physical: what you are now. The Cognitive: what you see yourself as being. The Spiritual: the perfect you, the person beyond pain, and error, and uncertainty.
- Main article: Physical Realm
Of the three Realms, the Physical Realm is the most readily understood as it behaves in much the same way that our universe does. It is the natural world as we experience it with our senses, consisting of space and time and adhering to empirical scientific law. Most Cosmere works take place primarily in the Physical Realm.
- Main article: Cognitive Realm
The Cognitive Realm is the world of thought and perception. It is also referred to as the subastral, and is known locally on Roshar as Shadesmar, though at least some academics of Silverlight have taken to using the term to refer to the entire Realm. The nature and appearance of objects in this Realm are shaped by the views of people and even the objects themselves. The environment itself changes from one world to the next, often exhibiting features characteristic of that world. Investiture, including that within souls, glows visibly within the Cognitive Realm.
While time appears to flow normally, space is also warped by perception. Some aspect of the nature of the Realm allows one to walk to space, and the distance between worlds is significantly contracted, so that travelling from one world to the next by foot is possible. Indeed, Worldhoppers generally make use of this Realm to move between worlds. Travelling between the Physical and the Cognitive Realms may be accomplished at Perpendicularities.
- Main article: Spiritual Realm
Little is currently known about the Spiritual Realm, which contains the souls, or essences, of people, objects, and ideas. It is believed by some on Roshar that the Spiritual Realm is a place of absolute truth--where things exist in their pure forms. Connection plays a very important role in the Spiritual Realm, where space and time have little meaning. 
|Shards||Ambition · Autonomy · Cultivation · Devotion · Dominion · Endowment · Honor · Odium · Preservation · Ruin · Survival Shard|
|Planets||Ashyn · Braize · First of the Sun · Nalthis · Obrodai · Roshar · Scadrial · Sel · Taldain · Threnody · Vax · Yolen|
|Terms||Adonalsium · Sliver · Splinter · Realmatic Theory · Investiture · Connection · Identity · Fortune · Intention · Perpendicularity · Spiritweb|
|Worldhoppers||Hoid · Khriss · Nazh · Iyatil · Mraize · Vasher · Vivenna · Galladon · Demoux · Baon · Felt · Marsh · Nightblood|
|Other||Seventeenth Shard · Ire · Shattering · Letters · Silverlight|