Necromancy is the practice of using magic spells to reanimate a corpse temporarily, usually to extract important information from the deceased. Similarly to goetia, the practice was banned by the Brotherhood of Sorcerers.
In The Witcher 3: Wild Hunt[]
Geralt can ask both Triss and Yennefer to use necromancy in the course of his search for Ciri. Only one of the sorceresses is willing to oblige.