Now when I have re-read selected parts of it again, I feel it have a few things in common with T&T. If you attempt an action, the normal thing to do is to roll against your stats (modified for difficulty by multiplication). Looks a lot like T&T. Also, the magic system have this idea of Active Resistance where your Willpower is reduced from the skill level rolled to loosen the spell. Once again I think of T&T and the Kremm Resistance rules of 7th ed.
Those of you who have read what I've written on that subject before know that I'm not that fond of Kremm Resistance. For me it seem way to binary. Actually, DQ made me think that maybe there is a good way to actually use it, kind of like the Active Resistance.
One way of doing it would be to let it be specific action. You can resist the spell, but then you wont do anything else. Then you have a few ways to handle it.
I think there are three basic ways to do it. You have to compare the WIZ scores between the Caster and the Target, and then you can use that for either affecting the INT to cast the spell, affect the level of the INT SR or lastly to affect the WIZ cost.
For fans of 5th ed, where there is no INT SR to cast a spell (which some have complained about as a nerfing of the Wizard without realizing that the extra AP gained evens it out), I think the last option is the way to go. That is, if you want Kremm Resistance in your game.
For us who use 7th ed, I prefer the option of affecting the INT score. Trying to get a number in a sensible range to affect the level seems harder. So, I present this suggestion.
Reduce the INT rolled for casting the spell the amount the WIZ score of the target surpasses the caster's score.
e.g. Caster with INT 16 and WIZ 16 cast a spell on Target with WIZ 20, so the Caster rolls his INT SR with an effective INT of 12 (20-16).
That way rolling doubles might still penetrate the defences, and since it will have to be actively resisted it might not be an option for every time and place.
I don't want to go the way of rolling saves or resistances all the time, it just wouldn't be T&T. This way the changes to the regular rules are minimal, and the binary nature of the rules as written is avoided. I never liked the way magic became so "scientific" and sure when you had the "you can't go there" sign of a high WIZ opponent.
You feel the WIZ drain effect is missing? Well, I think that will happen anyway. Just watch that Wizard working over time casting spells and throwing WIZ around. Survive a few rounds, or be smart and tempt him to waste some and then punch him. Otherwise I'm sure there's some way to re-engineer that one in as well.
Let me know what you think.