Ambient Necromantic Energy

There are places in the world which are suffused with necromantic energy, allowing the dead to rise far more easily than in other places. This energy is purposeless and undirected, rarely arising from the actions of a single necromancer but more likely to be the result of events on a much larger scale.
In areas with ambient necromantic energy, the remains of living beings have a chance to spontaneously rise as undead. This may be permanent or temporary. In some cases, they will be animated every night and appear to be inert during the day. The longer a corpse remains in such an area, the greater its chance of becoming permanently animated. These areas are also more likely than others to have ghosts, particularly if they were created by a large number of deaths. Ghosts and more corporeal forms of undead cannot interact: skeletons and zombies cannot see ghosts or vice versa.

Manifestation

Ambient necromantic energy, like other forms of ambient magic, can be discovered through the use of a Detect Magic spell anywhere in the affected area. It cannot be detected by living sapients, or constructs, without the use of magic. Cats are capable of identifying such areas.

Localization

Areas which tend to be high in ambient necromantic energy are places where an unusually large number of people have died of causes other than old age, or where such people are buried. The more violent the deaths, the more necromantic energy they provide. The sites of particularly powerful necromancy spells can also share these traits. The Lost City of Kadar is suffused with necromantic energy as a result of the spell which turned its remaining population undead, and any corpse which is present in the city after dark will be animated for the night even if there is not enough energy available to animate it permanently.

Type

Metaphysical, Arcane