Blood magic (or blood sorcery) refers to magic performed by the Kindred, fueled by the mystical power of vitae. Disciplines are powers which stem from the nature of vampirism, or in the case of the stranger Disciplines, the exotic natures of their creators. By contrast, blood sorcery seeks to achieve almost any effect imaginable by focusing the magical power of blood through an act of will. Any Cainite can learn to become stronger, track their prey by supernatural means, or tap into the bestial side of their nature, but blood sorcerers can summon fire, control the weather, and do things which are unnatural even by vampiric standards.
The most famous practitioners of blood sorcery are Clan Tremere, originally a group of mages who became vampires and created their own form of blood magic, Thaumaturgy, from their knowledge of Hermetic magic. Their unique powers were called on many times by the Camarilla, securing the clan's position within the sect. Blood sorcery is far older than the Tremere, however, and has been practiced in many forms throughout Cainite history. In ages past, Dur-An-Ki was the most prominent type of blood sorcery; it, and many other older styles, have survived into the modern nights.
Unlike standard Disciplines, varieties of Blood Magic form discrete Paths which can be studied simultaneously. However, one cannot take one's secondary Path of a particular variety of Blood Magic higher than one's primary Path. Moreover, one cannot engage a tertiary Path until one has mastered one's primary Path. Once one has mastered a primary and secondary Path, one can study as many tertiary paths without limitation as one would like.
With every level of blood sorcery purchased a character gets a free Ritual of the same level of the sorcery path they have purchased. The ritual is of the same casting style as the path purchased. One cannot get a necromancy ritual for purchasing Assimite sorcery or vise versa. To learn multiple methods of casting a ritual one must purchase the ritual multiple times.
Created by exhaustive research and extensive experimentation, Thaumaturgy utilises the principles of Hermetic magic used by House Tremere when it was still a cabal of mages, adapted to be fuelled by the inherent magical power of Vitae rather than the Quintessence known to mortal mages. While it is certainly powerful and versatile, it is organised very differently to the Spheres; thaumaturgy is largely unknown to mages, and universally distrusted and reviled by those who do know of it.
Necromancy is a form of blood magic that deals exclusively with the world of the dead: wraiths and the Shadowlands. Just as there are different styles of conventional blood sorcery, there are a variety of Necromancy practices. It is primarily practised by the Giovanni clan and the Samedi, Harbingers of Skulls and Nagaraja bloodlines. The blood magic style itself could be said to be an evolution and fusion of the Cappadocian's earlier discipline of Mortis and the Giovanni's trademark "Nigrimancy".
- there is a degraded form of Necromancy, posessible by non-kindred called Abyss Mysticism It and its rituals have the same limits as necromancy. Those who learn necromancy at in clan costs also get Abyss Mysticism at in-clan costs.
Dur-An-Ki ("Master of Heaven and Earth") or Assamite Sorcery is a form of blood sorcery practiced by Kindred of the Middle East and Africa, particularly the sorcerers of the Assamite clan and the Shango legacy of the Laibon. It is a very old form of magic, drawing from a huge variety of mortal religious traditions, and pre-dating Thaumaturgy, which it resembles in many ways.
Setite Sorcery is the name used by Kindred of other clans for the blood sorcery practised by the Followers of Set. "Setite Sorcery" is a term usually used in ignorance; Setite spells are closely guarded secrets and few outside the clan know of them in any detail. The term is never used within the clan. Most Kindred who have experience of Setite magic will have encountered Akhu, but in truth Setites practice at least four different forms of heavily religious blood sorcery. The trappings, traditions and beliefs vary between the branches and bloodlines of the clan.
Koldunic Sorcery or Koldunism is a form of Cainite Blood Magic practiced by the Tzimisce. It is similar to Thaumaturgy in idea but very different in practice. Major differences include Koldunic Sorcery requiring the service of the living earth rather than memorized rotes and rituals, Koldunism tending to be much more subtle than Thaumaturgy, and Koldunism requiring not so much an extension of will as being a master of the very material a Fiend wishes to manipulate.