Necromancy

Necromancy is a field of magic that is concerned with death. Necromancy can cause death, it can reverse death, and it can create the undead. Necromancy is not used openly in most societies, and it can be harmful to the planes as it drains the Astral Plane of Soul Matter. The creation of undead in particular is most dangerous.

At the end of the Age of Morakh, the wight Morthos used a wish to nullify necromancy and all of its effects. This was done to allow the Fourtold and their allies to battle Morakh without the interference of Zerk and his undead creations. This effectively banned necromancy in any of its uses, including restoring the dead to life.

In 6 M.D., a group of adventurers performed a ritual to re-establish necromancy. While successful, the ritual did not fully restore necromancy to its prior strength—it merely allowed the field to exist. This was enough for most minor forms of necromancy, but the undead were still unable to be created. This would have been a temporary condition, if it were not for the actions of the new god Kaladar, who devoted himself to preventing the undead for being created in any plane besides the Shadowfell (where Zerk's essence still lingered powerful enough that it could not be prevented).