Hi, my name is James and welcome to Code/Switch. I didn’t mean to write a Halloween article, I really didn’t, but the topics just too spoopy to not categorize it as such. Today I want to talk about Hemollurgy, more specifically this meme I’ve seen floated around the various RPG groups.

While that sounds fun and cool if you’re an insane person, it also sounds… wrong. People don’t have as much blood as we’d like to imagine, with blood being about 7% of body weight. Worldwide, the average adult male is 137 pounds or 62kg, so that gives the average male 9.59 pounds (4.35kg) of blood. Bloods average density is 1,060kg/M³, giving our 62kg man 4.1 liters of blood, just shy of a gallon. While that sounds like a lot the actual iron content of it is relatively small, with as much as a third of total iron not found in the blood at all, but in muscles and other structures. The iron found in blood is mostly concentrated in hemoglobin, with smaller amounts found in other structures like transferrins and enzymes.

Using our model here, the hemoglobin of our victim holds 2.58g of iron, assuming this is roughly 2/3^rd of the iron in the body, we estimate this person has ~3.8g of iron in their body, a normal baseline. (Seriously, I would show you the math but I had to figure out the molecular weight of hemoglobin and the weight of elemental iron with the assumption that most hemoglobins have 4 molecules of iron in them. Not only was it complicated, it was boring too!)

So now that you’ve drained this man of blood you break down the biologic components of his blood and isolate 2.6g of iron. You hold in your hand a lump of iron that weighs about as much as 2 paperclips. That wasn’t the hardest way to go about getting this material or anything, but whatever, now you want to make a testament to your battle prowess by fashioning the grossest longsword  of all time. The Core Rulebook says a longsword weighs 4 pounds. You go to your infernal armsmith with the blood of over 350 men and… get half a sword. There are roughly 453.6g in a pound, for a 4 pound sword you’d need 1,814g of iron. Sadly the blood of each vanquished foe only yields just shy of 2.6g, which will make you have to almost double your kill and exsanguinate count to 698 foes. 698 is a heck of a lot more than 359.

This isn’t necessarily made better by killing what seem like heartier creatures. Cows and pigs have similar hemoglobin levels when healthy as humans, but humans carry more total iron in their blood as hemoglobin. Because of this, I can’t with any speculative authority assume that orcs, hobgoblins or giants have a higher percentage of iron flowing through their veins. Just as a rule of thumb, the bigger the creature, the more blood, and the more blood, the more iron that can be harvested. Well, that is unless the creature has blue or clear blood. Please, just instead, take their weapons and melt them into some other trophy, one that’s reasonable!

Happy Halloween Everyone!