Reality is computable. Everything can be represented by math. But a lot of magic isn’t. It relies on weird intermediate steps, like the user “wills” something to happen. Steps that are equivalent to having a new limb, or in some cases an advanced neural interface.
I tried to figure out a magic system that doesn’t rely on any, well, magic. That is, any point where you can just say “the mage wills” or “the wizard pushes”. No irreducible steps.
Something closer to physics, but that still feels like magic. My big inspirations were smoothlife, which is a way of doing cellular automata smoothly, as a set of differential equations. At the other side of things is wireworld, which is cellular automata that’s very good for creating machines. And of course ra.
You can see an example of a wireworld computer here. It’s a pretty good analog for what a computer implemented in my magic system would look like.
At the moment, this is mostly just an overview. There’s not much about the how or the why, or what a world that had this magic system would look like. I tried to make something that would result in something close to Vancian magic, where you prepare spells ahead of time through concentrated effort. Keeping that from turning into an industrial revolution where wizards and machines simply turn out spells for mass consumption every day was tricky. As was figuring out some way to still allow for healing spells.
I think it’s a pretty self-consistent and reasonable cosmology. That is if you ignore social insects like bees. As one /r/magicbuilding commenter pointed out
The local K-T event didn’t have an asteroid strike on top of flowering plants and bees changing the landscape – it was just the bees and their honey-eating-seeker fireball spells. Social insects are good at developing finicky little physical routines based off of simple rulesets – they would be naturals and running active mana flows as part of hive maintenance.
Magic, a high level overview
Mana is a weightless, invisible, fluid. It forms an ocean over the lands. This ocean permeates pretty much everything. It may collect in valleys, it would be thinner at the top of mountains.
In order to weave a spell you compress and shape the mana using special tools. Woven mana is more “solid” then the backround mana of the earth, although it still doesn’t interact with physical reality at all. These weaves are locked to the earth. You can’t move them without more effort. Primitive cultures didn’t know how to move their spells, so what magic they did have was fixed to where they created. Generally just simple light spells.
Now days a magician wears a piece of lodestone. Generally a fist sized talismen. Active (charged) spell matrix paths will attach themselves to any lodestone they pass through. Mages will temporarilly activate part of their spell, in order to attach it to their personal lodestone.
A castle with walls made of lodestone would cause active spells to slip off of their masters lodestone. There are ways to move a spell weave without a lodestone, but they’re all active. Passing through lodestone will slow them down.
A spell weave by itself doesn’t do anything. You need to alter a part of the weave. Passing part of an active weave through volcanic obsidion will cause that part of the weave to be permanently altered. Now whenever that part of the weave is activated, it will heat up the enviroment.
There’s no definitive list of what substances alter spell weaves.
Mages and war
Mana regenerates over time, but you can drain a battlefield pretty quickly. One of the simplest spells simply drains surrounding mana until it runs out. You don’t need anything beyond the most basic of tools to make an area a virtual desert.
For this reason, mages tend to be pretty solitary. There are a number of ways you can get around this limitation however. You can transport natural mana in giant, immaterial, spell-woven cages. The problem is that the cages needs mana to continue to function. Those cages will drain their contents in a few days if there’s no backround mana at all. You also need to strongly anchor the cage, becouse it has a lot of “weight”. It will slip off a common lodestone.
The gods can gift you mana, and will occasionally give mortals mindbogglingly complicated spell weaves.
Magic and healing
Magic is no better then a surgeons knife when it comes to healing, it all depends on the skill of the surgeon. The gods are very skilled, and will gift mortals with very complicated spell weaves. Trying to reproduce a god’s spell-weave would be like trying to build a microchip when all you have is steam engines. At the very least you’d need a microscope that can see spell weaves.
Magic and bees/gods
This system has an obvious flaw. Mana is basically a source of free energy, and evolutionary processes would have acted on that. You’d see very complicated biochemical mana weaving. Which quickly upsets the entire power balance, as evolved mana weaves would be a hell of a lot more intricate then anything a human could create. Not counting things like pure mana entities and other over-powered creatures.
My solution to this was the gods. At some point in the past beings of mostly pure mana found themselves running out of what is a limited resource. So the fought, and eventually ascended, leaving earth largely barren of mana for millions of years. That allows for evolution to more or less take its normal course, and gives us a reason for gods.
Wherever water intersects a spell weave, it acts as a window into the world of mana. Immerse a spell in water and you can clearly see the whole of it. Naturally, when it’s raining you can see all of a mages prepared spells floating around them.
You can also craft lenses. Simply weave some mana into a vial of water. You can’t see very far through one of these lenses however. Beyond 3 feet there’s only darkness.
Magic an tribes
There are a huge number of materials that can affect a spell weave, in the same way as volcanic obsidian affects a spell weave. There are materials that turn a weave into a sort of “sensor”, activating a part of a weave when something is nearby. There are materials that alter a weave to it moves things in the physical world, or so that it moves itself.
There are a lot of different materials, and some tribes have a monopoly on them. For example, perhaps only one group can create lighting?