Arrowflight‘s magic system is…
Well, it reminds me of something.
I attempt to create a Wall of Earth spell from the Elementalist “Wall” template. To make it a literal wall, I have to add at least an Armor Value of 1. That adds 1 to the base difficulty of 2. But that’s only an AV of 1 — no tougher than heavy cloth. If I want my wall to be as hard as, say, plate mail, I’ll need an AV of 9. Each level of AV increases the difficulty by 1, so now I’m at a difficulty of 11 — that’s not going to work. So, I add a requirement for a two-handed motion (rather than the default single hand motion) for -2 difficulty, a short incantation (rather than the default single word) for another -2 difficulty, and a rare focus item — let’s say, the heart of an earth elemental — for a -3 difficulty. Now my spell has a difficulty of 4?
Dunno. It is a LOT like the spell-creation system I designed for Hocus Pocus, Mumbo Jumbo. Dunno.
Maybe that’s what I get for writing stuff like that out and then posting it for free.