Outside of the multiverse are the non-physical realms of ideas, or outer planes, such as the the Realm of Chaos or the Realm of Dreams. They are impossible to bodily enter, but can be studied and used to influence the physical planes through spellcraft. For example, elemental summoning magic pulls entities from the corresponding elemental Realms, while positive and negative energy spells draw their nature from the Realms of Light and Darkness. The Outer Realms are the least understood, but are often said to be home to the gods, the souls of the dead, and the source of magic itself.
Spells that allows for planar travel function differently in the Starsea. Those that allow travel between planes, such as plane shift, allow travel only into or out of the astral plane through the nearest astral channel. Those that create gates between planes, such as gate, create gates only to the astral plane along the nearest astral channel. Spells that rely on specific planes, such as etherealness or astral projection, do not function normally or at all.