
They would then negotiate for this ability in exchange for their blood and soul. To begin using the blood magic system, a spellcaster would need to contact a sufficiently powerful outsider. A spellcaster who does not have enough hitpoints to cast the spell, but has at least 0 hit points, may put themselves into the negatives (or even die) as a result of casting the spell. As long as they are above 0 hit points, they are able to cast spells. Spellcasters who practice blood magic do not use spells per day, but rather use their own hitpoints to cast spells. Blood magic is an ancient and forbidden art, taught to mortals who have formed a Blood Pact with a powerful outsider. The blood magic system presented here allows casters to cast more than they would normally be able to, at the cost of their own life force.
