What would be a appropriately balanced Blood Magic System?

[GunslingerRadiant]

I want to create a civilization where the users of the magic burn away their own blood to power magic. The only blood you are able to use is you own. Any thoughts?

[TheSurvivorofDeath]

Okay does the blood have to be inside of you? Because that makes it harder. However, if you can use any blood as long as it’s your own, you can just store your blood into a stockpile until you need it. Then you can make effects with far more power than you would with your own blood volume, and can even avoid negative effects from depleted blood. It’s an interesting idea.

[TheWanderer he/him]

I suppose it would depend in part on a few factors.

1. How widespread is this ability? Does everyone of this region have it, or is it something that they acquire, say via some kind of ritual?

2. What abilities does the burning of one's own blood provide? Destruction, healing, or some form of conjuration via manipulating the blood's form?

3. What beliefs do the culture have about this power based upon the prior factors.

For instance, assuming that one only gains blood magic through some kind of ritual, and that blood magic allows someone to heal another of their wounds. I could easily see it becoming some kind of holy magic in which those practitioners are viewed as saint like entities. 

If however the magic something that people are born with and it provides some sort of combat effect. Say for instance the blood can solid as a weapon and gain traits such as being corrosive. I could see it becoming somewhat taboo, or perhaps a favored power for assassins. As the more wounds they take in theory the more power they have. 

As a random aside, if you want blood to potentially be used simply as a kind of magical battery. I would then say it could depend upon how other regions in your world utilize magic. Say for instance in other places you need magically charged crystals to cast spells. These blood mages could in theory be seen as having a closer connection to magic via their ability to seemingly utilize it at will without such crystals. 

If so, they might at one time have been the dominant force in the world, albeit somewhat limited by the blood within their body. However, if say your world has advanced to a point such crystals could be mined easily. They may now be in decline, as the ease of use may have fostered a kind of negligence in exploration of better ways to utilize their power.

I do hope this helps and I want to thank you for the thought experiment.

[GunslingerRadiant]

Here is the current outline:
 

Bloodcaller

Set primarily on The Crimson, massive island on the center of one of 3 continents. It is ruled by the Worldking, a master of Bloodcalling, a dark art that was considered taboo for thousands of years, until he Mastered it, using it to start the Crimson Guild and dominating the people with his elite group of Bloodcallers called the Crimson Knights. They are a combination of assassins, cavaliers, and foot soldiers. They can burn away their own blood to increase their strength, speed, durability, senses, and a number of other things. This magic can be used for other things, like traditional spells: fireballs, flight, weapon enchanting, illusions, summoning objects, and creating animated beings. This is however, only the start. But, we can go into that later.

 

Setting: The Crimson had been blessed with massive natural defenses, and incredible agriculture ability. This however required an incredible amount of Bloodcalling, and turned all non-human Flora and Fauna a dark red, which gave the mega island its name. It has sizable cliffs that can't be climbed by an ordinary man. It has a field quadrant, a forest quadrant, a mountain quadrant, and a desert quadrant. At the center of it all is Bloodcrest, a massive capital city, spanning hundreds of square miles. It takes 3 days to get from end to end on foot.

 

Magic: Users can burn away blood that they are touching to power several different types of spells. They are directed by thought, but have a byproduct rune that can be sensed by Bloodcallers nearby. The spells either

1. Burn away a larger amount of blood

2. Burn away a specific number of milliliters of blood a minute

The spells are basically limited by the user's knowledge and imagination.

[Through the Living Shadow he/him]

It doesn’t matter how powerful the magic is, as long as it is cool (pretty freaking awesome man), and there is something else to counter it.

[Lord Stormer]

Well, since you've said that you can only use your blood, so I would assume everyone has a unique type of blood, thus throwing off the possibility of transfusion, except if one desires an excruciating death. That way, it wouldn't take much time for civilization to realize how potent it is to transfer your own blood to your enemies, either by injection or by a custom ability.

Otherwise, it would also pose a VERY intriguing tribal divide if the inhabitants of your planet have rather human like classification of blood types. Some blood types are reciprocally transfusible (A to B, B to A), but some are not (C to D, not D to C). You should explore about that.

Edited September 27, 2024 by Lord Stormer