Magic

Much like gravity, day cycles, and even doorways, Sigil has its own natural laws regarding how magic functions and behaves.

Magic in Sigil

Arcane

Every arcane spell is part of a school of magic. These schools organize spells by the process of casting and the effect of the spells. As such, each school is a brief summation of what a spell does. In Sigil, Arcane magic is generally unaffected by The Lady, though planeshifting and teleportation magic from and to Sigil, not within, are both banned and punishable by whatever way The Lady deems fit.

Divine

Most CagersA native or resident of Sigil. can be safely categorized as agnostic. It's not that they don't believe in the existence of deities–such would be a difficult thing to deny in a universe filled with divine magic, Angels and Fiends. Rather, they don't quite believe that the Powers are the be-all end-all as the PrimesA native of the Prime Material Plane, where most people start before ending up in Sigil. tend to believe.

While there is only one entity in Sigil that could be described as a deity–The Lady, herself–that does not mean that all beings with powers bestowed by a deity have those powers immediately cut off. If a Cager wishes to keep those powers, they need an instrument of focus to draw their powers from. Usually, this is a holy symbol of some kind worn on their person, but can also be a statue located in their home. Often, this is called a “divine tether”.

Primal

Druids and other children of nature revere it above all, gaining their spells and magical powers from the Prime Material Plane, itself. They don't necessarily draw from any deity or other entity, and only must commune with nature to gain their power. Unfortunately, Sigil is as unnatural as unnatural can be–there are no natural resources in Sigil, nor any direct connection to the Prime Material Plane. Thus, anyone who primarily uses Primal Magic before entering Sigil may not use it while inside.

Many druids have found a way around this by committing themselves to worship a deity of nature, and draw their powers through a divine tether. In that case, their powers would be granted by said deity, and would be considered Divine.

Magic in the Outlands

Unlike Sigil, the Outlands are not a good place for any magic-wielder to flourish. The closer someone gets to the Spire, the more magic be inaccessible until you reach the base of the Spire, in which no magic can be cast. This applies to all types of magic. It is said that deities used to meet at the very base of the Spire to confer, solve disputes, and revisit their power-balancing divine agreements every now and then, as it is a neutral ground for all.