Re: WWR
Well, I think a general term all of us can agree, is that "magic" (or the supernatural) refers to things which happen / can be caused to happen, which don't have a scientific explanation as we understand physics, chemistry, biology, science to work.
a couple of thousand years ago magic explained lots of things, as our ancestors didn't understand science. Why did that lightning bolt hit my house? Wrath of the gods. Why do the seasons change? The daughter of spring is visiting her husband in the underworld, and her mother is sad.
from that, you can break it up into, well, magical science, where magic has rules it follows, some consistency.
This might be magic as nanotech, or as Psi powers. It might be magic as done in Jack Chalker's Well World series, where people and very advanced machines can rewrite the equations of reality.
Usually these include a limit on what can be done (which a lot of games have for balance) GURPS magic typifies this. I would think that even a well educated non-mage could understand the principles of magic
And more magical magic.
This is where even the practitioners don't fully understand it. It might not have internal consistency. Thinks work sometimes, and sometimes not.
Deadlands classic, more so than Savage DL has this, particularly with Hucksters. A huckster doesn't understand what he's doing, really, he's not doing it. He's browbeating a spirit into doing it.
DnD has this. You cast a spell, it works. You try again, it doesn't (because you only prepared it once). Smacks of the definition of insanity, trying the same thing twice and expecting different results; in this case the different results are going to happen
Some extreme post apoc settings might includes this. Stone age tribesman mashing buttons on a keyboard, knowing that sometimes it will open a door. Stopping at any red light, because once legend has it someone didn't stop, and a demon (traffic cop) took away the mighty hero never to be seen again. (locked in jail for jaywalking, starved to death) But the other guy stopped to drink water. So now, at every red light, you stop and drink water until it turns green.