So I was thinking about healing magi and it occurred to me that a really handy spell to have would be something that would ward you from disease, or at least increase your chance to resist it. Yes, a magus could certainly cure a disease once he had it, but that costs vis, which we will assume he doesn't want to spend. He could also dramatically increase his chance to recover from a disease without spending vis. But that means he has to catch the disease first, with all of the detriments that entails. What I want to know is whether there are any prophylactic magical precautions he can take to avoid catching the disease in the first place.
Now, Corpus gives a bonus to resist disease, so that's a good start. We'll assume that the magus has a decent Corpus, which definitely reduces his chance of catching disease. But like i said, avoiding the disease in the first place is the best option.
A&A gives a guideline for a CrCo effect that gives a bonus to disease Recovery rolls. But, of course, by that point you've got the disease. I'm looking for some kind of effect that could be set in place before the magus was exposed to the disease that would allow him to better resist the disease in the first place (e.g., when going to treat some people suffering from the plague). Four possibilities come to mind.
The first, most generous, possibility is that bonuses to disease Recovery rolls also give a bonus to disease resistance rolls. That makes it easy. Just make a spell that gives a bonus to disease Recovery rolls and you're set. Of course, this is not mentioned in the disease rules in A&A right where it would be if it was to be true. So perhaps this is a non-starter.
The second possibility is to posit a similar CrCo guideline for giving bonuses to disease resistance rolls as there is for disease Recovery rolls. So you'd have base CrCo 1 for a +1, CrCo 2 for a +3, CrCo 3 for a +6, etc. That makes sense, but has no support in the rules anywhere.
The third possibility is to assume a ReCo warding effect, effectively warding against disease humors. Clearly you'd have to have it scale with the severity of the disease so that your spell could only ward against a particular severity of disease or less. And, of course, I have no idea where to peg the base value for warding against a minor injury. But it follows the general idea of wards. Alas, this possibility also has no basis in the rules and has to be extrapolated.
Finally, the fourth possibility is that it just can't be done. I can accept that as the answer if that's the consensus of respondents. But it seems to me that magic in ArM5 already does a whole lot more improbable things than warding against disease.
I can't help but notice that you can modify the disease Recovery check up to +18 (as well as adding your Corpus bonus). Given that the most severe disease is a severity 15, that means that you can pretty much guarantee recovery from even the most severe disease absent a botch on the Recovery roll. Surely finding a way to ward against the disease in the first place should be within the realm of possibility.
So, what does the groupmind think about this?