Oh sweet! A prompt for me to detail my Magic System!
Okay so I'm actively writing a book called Solstice (
https://www.scribblehub.com/series/379579/nanowrimo-solstice/, the first time I ever actually linked to my work on the fora), and in that book I have a neat little magic system that has influences from many distinct works. If I had to make a basic explanation of it, it'd basically go like this:
Magick is the manifestation of phenomena not otherwise possible by Natural Law. This includes pretty much anything you'd expect from a fantasy setting.
The energy used to perform Magick is called Æther. Those who can manipulate it are called Magi. Those who cannot are out of scope for the purposes of this advert.
By itself, Æther can produce force effects, solidify into objects (think spectral arms/armor, etc. You're basically hardening it into a solid), perform telekinesis, read and shield minds, and manifest your spirit as an atmospheric pressure on your opponent. Oh and it can also strengthen yourself as well. These effects are usually divided into
Body,
Mind, and
Spirit. Each Magus is typically talented in one of these three areas.
Magi can also Attune their Æther to one of the Classical Elements. A Magus gets at most one Element to be able to do this with, barring shenanigans, and they need not always perform the attunement. Fire-Attuned Æther produces Fire Magick; ditto for Air, Water, and Earth. Magick Attuned to an Element is far more costly than Unattuned Magick, but it auto-wins clashes with base Magick (so if you throw a fireball at me, and i defend with a wall of solid Æther then fuck me I'm getting burned.)
What Magi can
also do is Aspect their Æther to either Light or Darkness. This is actually far higher-level than simple Attunement, but the good news is Every Magus has an Aspect instead of there being "empty" Element-less Magi. Light is fast, sharp, and able to clash with Elements. Dark, on the other hand, is slow, but heavy and persistent, making it very good for shielding and brute force. Aspects and Elements are equivalent in "priority"; Light will clash with Fire, but override Æther.
The real fun comes in when you do both at once. This unlocks one of 16 Concepts, depending on which Element and which Aspect. With this, you can perform feats such as actual creation of matter, summoning demons, teleportation, healing, and creating gravity wells. Magick of this sort is Conceptual, and Concepts are a higher priority than both Aspects and Elements.
Before I continue, Here's something important - Men and Women cast differently: Men pull Æther from the environment, and run it through their Ætheric Vessel, which acts as an engine that drives the conversion of Æther to usable Magick. Women, on the other hand, store Æther in their bodies, and push it out through their Vessels into their bodies wherein they channel it into the desired effect.
Finally we have Spell Circles. Spell Circles are, well, Circles with geometric designs and runic text in them that basically act as complex formulae to auto-produce certain effects. While a Magus can theoretically do any Magick without a Circle, Circles have obvious utility when you no longer have to juggle factors in combat, and can often perform those specific effects better. Unfortunately, only men can really utilize Spell Circles, as drawing one permanently marks your Soul and changes how you do Magick. Men can overcome it with force of will, but women cannot; their Æther is intrinsically bound to that Circle. To make up for it, though, women are immune to a spell that seizes all Æther in an area and therefore denies men spellcasting.
Finally, there is one day of the eight-day week that no Magus is allowed to use Magick, ever. This day is called Enday, and takes place between Sunday and Monday. If you cast on an Enday, an eldritch abomination rips into the world and starts fucking up everything around and including you. They are immune to Magick, and really fucking terrifying, so this lesson gets hammered in the heads of magickal children pretty fucking fast.
That's about all I have right now on my system. It, like the book its in, is still being developed, but these are the main foundations.