[...Yeah, against her expectations, Rita's getting a slightly sinking feeling that this could end up backfiring. Clarke's just a little too overenthusiastic...even if Rita would still prefer the other girl have some protection against magic than none at all, too.

...It's still jarring just how quickly she went from looking at it in abject horror to diligently tying the lacing. It takes Rita a moment to blink and consider the question.]

Huh? Oh, well... It's not that simple, since it still depends on the power of the spell and the mage casting it, too. For someone like me... [Nevermind that she can't actually use any magic presently.] I'd estimate it would give you...maybe fifteen percent protection, as long as it wasn't one of my more powerful spells. It's still not really something you can put a number on, though.