isles-of-maga/cosmology.md

Cosmology

There is only one world: the physical world that Agreus occupies. Demonia is not in another plane of existence. Rather, it is deep underground. Portals to Demonia physically teleport what passes through it, the same as other teleportation magic. Magic is also physical: it comes from a creature's life energy, for Magic-Users through their knowledge and for Clerics through their faith.

Alternate Timelines

Although there is only one world, it is possible to traverse alternate timelines using magic. However, it is difficult to do so and the impact of such travel on Maga has been minimal. Only Ultimatum, Demon Lord of the End Times, has full knowledge of how these alternate timelines work and refuses to let mortals use such powerful magic for petty reasons.

All except one timeline are "undoomed" timelines, while the information given here describes the doomed timeline. An undoomed timeline is one that Ultimatum eventually abandons in order to shift towards the doomed timeline. Therefore Ultimatum may be present or absent in an undoomed timeline during a particular campaign. The doomed timeline is the only one with the continued presence of Ultimatum.