[Rindis]

At this point, I'm breaking off to nail down what I think a magic system needs to have a generally D&D feel, and figure out what that needs:

1) Spells need to be reliable. In D&D, when you cast a spell, short of getting interrupted mid-way through, it works. Spells as powers, and therefore GURPS Sorcery does this very well.

2) Spells should have non-standard limits or restrictions on them. One of ways magic can feel magic is if there's a hint of the unknowable, or illogical about them, and a lot of the emblematic D&D spells have this. Spending some effort on spell/ability building helps with this.

3) Mages should be unarmored. Unfortunately, Sorcery doesn't support this, and the suggestions in Thaumatology don't help. My current thought is to increase spell fatigue expenditure by encumbrance level, or something similar. (Assuming this isn't just considered a setting switch, how big a modifier on Sorcerous Empowerment would this be?)

4) Spellbooks. I don't see any need to replicate the resource management system of D&D spell slots, but there should still be a reason for mages to need to lug these around, with loosing them becoming a problem, and an enemy mage's book(s) being important loot. (Also, the creator of Forgotten Realms loves them, so loosing spellbook utility would detract from the intended flavor.)

In an earlier version of these thoughts, my idea is that the spellbook was a reference for refreshing one's memory of exactly what to do, and a precompiled reference for changes needed as star positions and the like change. A mage should then recheck his book every day, but could attempt spellcasting without it at an increasing penalty to skill.

Any thoughts on spellbooks? The last paragraph doesn't work with Sorcery, but I still like the general explanation, if that ends up being salvageable.