I’ve been thinking about how to institute blood magic into my upcoming game. The theme is based loosely on the aesthetics of old pulp Sword and Sorcery stories, which of course means blood magic. Now, I could just chalk it up to flavor, but I want something that makes blood magic enticing and dangerous. Something that a PC caster would be tempted to dabble in (though knowing the soul-consuming risk).

(Art by Erol Otus)

First, I thought of an HP drain system. 1 point of damage (possibly bleed) per spell level. This is mildly unappealing because blood magic loses its danger as the caster rises in level. On one hand, I don’t want it to be a constant danger, but on the other it kind of makes sense (a spellcaster getting better at controlling the flow of the dark magic).

Related to this, some sort of a system to make blood magic a gamble instead of a tactical consideration. A Fortitude save with a DC equal to 10+Spell Level, or a caster level check with the same DC. On a success, the spell goes off without a hitch. On a failure, bleed damage (higher than the bleed from the HP drain system… 1d4 per spell level?). Fortitude makes sense, but wizards and other low-fort casters could easily fall behind farther than I want. Caster level checks are, I think, the way to go here.

This brings me to another consideration. Undead. Undead cannot suffer bleed damage, since bleed damage specifies a living creature. As a result, undead would not be able to use blood magic. This is troublesome, as a lich or vampire using blood magic is flavorful and, honestly, pretty cool. Also, in my setting, the characters are unlikely to ever directly encounter a powerful lich or spellcaster vampire, so combat spells are not a consideration.

Thus, another subsystem. Ritual blood magic. Using the Occult Ritual rules and tweaking them a bit, I’m sure I can make something for those undead blood mages (or regular blood mages). The backlash for blood magic could be along the lines of “This ritual requires the slaying of unwilling, helpless, nonevil creatures with at least X total hit dice.” For more powerful rituals, you could get more specific, like “This ritual requires the slaying of an unwilling, helpless cleric (or warpriest, or inquisitor, etc.) of a Good-aligned deity of at least X hit dice,” (Suddenly, when the players go to a temple for healing the only holy man (since most priests should be classes other than clerics, notably experts or adepts) capable of healing them was kidnapped by an evil cult for a blood sacrifice!) This doesn’t follow traditional backlash rules, but I’m looking to adapt a system into another, not work within the system. The exact effects of the ritual could vary, but could range from making a lich’s phylactery (or destroying one, if you want to give the players a moral quandary if they do obtain one) to opening a gate to the Abyss for a cult’s demonic patron to invade the material plane from.

Of course, some spells might require a significant sacrifice in addition to the above. Resurrection spells might require the self-sacrifice of the spellcaster or another willing to trade their life for another. Spells that call outsiders could require the sacrifice of small animals.

Going back to standard spellcasting, blood magic needs to have some sort of benefit. An increase in save DCs or effective caster level would be the simplest and least obtrusive. The difficulty would be figuring out the exact bonuses, which I attempt to do in the sample feat below.

All of these thoughts have mostly been to help get the cogs moving. I, personally, am going to use the second blood magic method and integrate the blood rituals. Using blood magic should be a feat, such as the one below, but it could also just be an option to learn.

Blood Magician (General)

You have learned to use the magic energies in blood to fuel your spells.

Prerequisites: Caster level 3rd

Effects: Whenever you cast a spell, make a caster level check with a DC equal to 10 + the spell level. If you succeed, you cast the spell as normal and either increase the save DC or caster level of the spell by +1 per every three caster levels you possess. If you fail the test, you suffer 1d4 bleed damage for every level of the spell you are attempting to cast. You still get the bonus to save DC or caster level. Unlike other damage taken while casting, you do not have to make a concentration check to avoid losing the spell. You also gain the ability to perform blood rituals.

Title is a reference to Blood Sacrifice by Visigoth