Part of the reason for my months-long hiatus from blogging was that I finally read enough Harry Potter fanfic that I went from “I could do this” to “I have to do this.” If you’d like to see more of my writing, on a more regular basis, the first book of a Dresden Files/Harry Potter crossover is now getting posted twice a week on fanfiction.net. Dresden winds up going to Hogwarts after his mentor’s death, instead of a farm in the Ozarks. Shenanigans ensue.

The interesting thing about crossover fanfic is using one work’s worldbuilding to shore up the other’s, and this is potentially useful for designing games as well. My goal for the series was to make as much of the magic style from Dresden Files be true as possible without explicitly contradicting the worldbuilding in Harry Potter. Since the worldbuilding in Harry Potter is diaphanous enough to ride an elephant through in a lot of places, this had the interesting result of shoring up the whole into what feels to me like a much more reasonable structure. So this could probably be a good way to round out a setting you’re running a game in, if the supporting fiction is too thin: find a somewhat compatible property and use it for inspiration to round out your world.

Interestingly, in creating a hybrid magic system, I also came across a potential way to wrap my head around how the traditions work together with incompatible paradigms in Mage: the Ascension.

Without further ado…

This is the summary of how magic works as Justin taught it to me and I explained it to the kids who came to my enchanting tutorials. Hogwarts doesn’t explain most of this unless you take arithmancy, and even then, some of the theory is lost in the practice.

Magic is, quite simply, imposing your wishes on reality. Those with access to the gift can want something impossible to happen badly enough that it happens. When a wizard is young, this “accidental magic” is the only way he knows to enact his gift. When a wizard is old and powerful, he can, likewise, merely think magic into being. In the middle, wizards are taught complicated practices to organize this into spells that they’ll eventually try to abandon. The difference between the untrained child and the ancient master is control over these wishes. Accidental magic doesn’t do exactly what you expect to happen when you want it, but a master can create magic, when needed, every single time.

The first question you need to ask to understand how the process of magical training works is: why are most spells in Latin?

The reason is because it keeps the magic separated from your speech. If magic spells were in English (or whatever modern language you speak), you’d risk accidentally casting them in normal conversation. The pathways of your brain that control the instinct to create the magic get trained by the wording of the spell. Hogwarts professors probably don’t work hard enough to get kids out of the habit of referring to spells by their incantation rather than their English name. One day, some kid is going to talk about the fire-making charm as “incendio” and accidentally set a friend of fire.

As I understand it, every culture with magic similarly uses a language that’s not frequently used for conversation as their language of incantations. The Romans used ancient Greek, Aramaic, or Etruscan. Non-Western wizards use outdated forms of their own local languages.

Of course, you can’t just say the Latin word for something and consider that a spell. The use of a meaningful word in Latin is useful, but that’s because even if you don’t really speak it, it does have a meaning that you can latch onto. “Incendio” is a word that more or less means “I set on fire.” You could probably make the magic work with a different series of sounds, but it would be harder to remember.

The most important thing is that “incendio” is four syllables, and arithmantically adds up to a 5-4-4-6 structure (i is the 9th letter plus n is the 14th, which adds up to 23 which combines down to 5). There’s no way I could effectively summarize the exact practicals of how that number adding works or why 5-4-4-6 is a similar numerical array to related spells. You’re either just going to have to take my word for it or commit to five years of arithmancy class. Essentially, any word that was close enough to a 5-4-4-6 cadence could be used as the incantation for the fire-making spell. Why are some incantations really bad Latin? Because the more correct Latin didn’t fit the arithmancy.

There’s a ton of math in figuring out an incantation, and that’s just half of a spell. The other half comes in using your focus.

At the simplest level, the foci that I use for my magic (staff, blasting rod, etc.) are limited to particular types of spell. Spells that create or change motion are fundamentally similar in their arithmancy, so I was able to fit a bunch of them into my staff, and I have to differentiate between them by the different incantations. Also, turning the staff into different types of gestures improves the spell (but I can get a weaker version by just holding it and yelling). I’ve embedded a spell matrix into the staff, which is a three-dimensional (some say a four-dimensional) shape that also defines its parameters. The arithmancy of the incantation hooks into the arithmancy of the matrix to basically create a momentary bubble of possibility for the wizard’s thoughts to fill with the magic.

It’s all extremely technical, which is why any Hogwarts student that skips arithmancy and ancient runes has pretty much no idea how it works. They’re training engineers, not scientists. Most wizards never need to know how their tools work.

A wand is the most complicated piece of technology that wizards have come up with. If my staff is an abacus, a wand is a mainframe computer. Both can help you add numbers, but the computer can do so much more but is so much harder to understand. In a tiny, concealable form factor, wandmakers create a focus that can allow you to perform any spell, theoretically up to the maximum possible power possible.

The first drawback is the finesse issue. For whatever reason, I and a lot of other wizards have a really hard time using wands. It’s some combination of conceptual and down to sheer manual dexterity (I have really long arms and that messes up the precise spell gestures). There are probably a ton of great wizards who leave wand-focused schools thinking they’re bad at it, because they just can’t figure out the only technology those schools teach.

The second drawback is compatibility. While every focus has some degree of resonance with the aura of its user, wands are 100% locked into it. I picked the materials for my staff because they worked for me, but it’s still extremely effective in any wizard’s hands. A wand that’s a poor match, however, may barely work at all.

It comes down to the secret technology of how they fit all those spell matrices into one focus. My suspicion is that the wand bonds to the wizard to basically turn his whole body into a completion of the matrix. A poorly-matched wand means all your matrices are malformed before you even start casting.

The third drawback is the gestures. Most of the matrix for a spell is in my staff so I can get away with just pointing. But a wand has to fit every possible spell in, which means it can only carry the most common arithmantic elements of all spells, and algorithms for transforming wand motion into the rest of the spell matrix. Why do you have to swish-and-flick to levitate something with a wand when I just have to gesture with my staff? That precise motion is finishing the matrix for the spell, which I’ve already fully encoded into my staff. Wand users have to get very good at training their muscle memory.

Ultimately, advanced users tend to start getting into magic without words or foci. Without the words, you have to create the spell in your head without the mnemonic aid triggering your brain. Without the focus, you have to fully visualize the matrix. Without either, you’re basically relying on your imagination to fully generate an extremely complex mental construct with no aids other than your own brainpower. You quickly find that using words and tools to train your unconscious mind to do the heavy lifting makes a big difference.

And, when it comes down to it, all of this is training your brain. Arithmantic correspondences and spell matrixes aren’t real. Non-Western traditions use completely different methods of structuring their magic. Western wizards use the structures they do because they’ve been codified and imbued with meaning, so it’s something your brain can latch onto. I’ve heard some people suggest that part of it is also a “universal unconscious” thing: if enough people with the power to make their wishes reality think that the letter A is equal to 1, then that becomes true. I’ll leave that up to the Department of Mysteries to weigh in on. All I know is that every bit of it is a mental construct.

You are a wizard. Your thoughts and desires can make impossible things happen. Every bit of magical praxis you’ve been taught is simply about making it easier to do what you want and harder to have accidents. It all comes down to: if you wish hard enough, you can change the world. Magic is just a set of tools to help you make the best wishes you can.