Blood magic uses blood to power talents, spells and rituals, blood charms and various other types of magical effects. A characteristic that defines blood magic is that it requires some form of sacrifice by those using it.
There are different schools of though surrounding the use of blood magic. Some believe that it should only be used in its traditional form, as a means to make oaths binding. Others believe that it comes from the Horrors and those that use it are corrupt. Still others believe that the end justifies the means and employ it to combat the Horrors.
Because of the connotations that the term ‘blood magic’ holds, practitioners tend to refer to it instead as “life magic”, and reserve the term “blood magic” for reference to uses of death magic.
Blood magic developed in Thera, from the act of swearing an oath and sealing it with blood. In its original form it was a mundane but symbolic gesture. Over time, the repeated use of blood in these oaths instilled the act with a pattern and it became a form of magic unto itself. As the practice of blood oaths spread, people began exploring different uses for blood in magic. Consequently it came to pervade every aspect of magic.
Spells and Talents
When used to power spells and talents, blood magic generally manifests in the form of Strain. In some cases, it may also cause wounds or permanent damage.
Charms and Armour
The wearer of a blood charm or certain types of living armour invests a small amount of their own life-force within the item to power its magic. The wearer takes a small amount of damage that cannot be healed until the item is removed.
Rituals may require certain blood from a certain type of creature in order for the ritual to be effective. Creatures here includes Name-givers.
By voluntarily taking Strain or wounds, an character can temporarily raise their capabilities to perform impossible feats.
Swearing a blood oath typically last a year and a day or until broken. Examples include the Blood Peace, Blood Promise and Blood Sworn oaths. Breaking a blood oath causes permanent wounds and scars.
Sacrifice magic consumes an the life force of the individual using it in order to empower a prodigious act. Examples of this type of blood magic include the Dying Act, Dying Curse, Dying Legacy and Dying Oath. As it will be an character’s final act, they are not undertaken lightly.
An adept may swear a special type of blood oath to a loyal un-Named spirit or creature. The magic provides benefits to both parties, and lasts until the oath is broken or one party dies.
Death magic uses a third party to supply the sacrifice necessary to power its effects, generally an unwilling victim. Death magic is outlawed across Barsaive, though the Therans are reputed to employ this form of blood magic on slaves.