Rookie questions - pt 1 - repeat casting / beefing up spells

Hello there - I'm new to this forum and new also to Ars Magica.

I've been running a campaign since late last year, and have some player questions that I'd like support in answering. I've mentioned my rulings, but would welcome your feedback.

The first group is on repeat or multi-casting certain spells, or on beefing them up.

Q1. - Can you cast spells like Preternatural Growth (AM5 - p131) twice on the same target, to obtain +2 Size?

My ruling was no - it only has the potency to work successfully once.

Q2. - Can I research Preternatural Growth at a higher level, to obtain a greater than +1 Size increase? If so, how many more spell levels would be required to get to +2?

My ruling was no. Although I could see the logic of the question, there was no clear guidance in the MuCo guidelines. Also, in my campaign, I was concerned about the mages turning a favoured companion into a tank via various such spells, and getting him to do all the mundane fighting - a concept I found a bit dull.

Q3. - Can I repeatedly cast a Creo Animal spell round after round, to summon many animals of the same type (e.g. Wolves - to them command to fight)?

My ruling was yes, but my caveat was that if the Mage successfully summoned 50 wolves, it would be dull to roll dice for them all in a combat situation so a special ruling was needed. I therefore said that it would be permitted for story purposes when a 'mass combat' occurred (e.g. vs. 50 pirates) and the wolves could be summoned and we would just tell the story of the fight. Alternatively, I advised that I would frig any small scale fight so that the Mage didn't have time to prepare 50 wolves well in advance of the fight; if the Mage wanted to spend 50 combat rounds actually during a combat summoning one wolf after the other, that would be fine, as it would be similar to casting Pilum of Fire one round after the other.

Q4. - Can I obtain Mastering in Wizard's Sidestep in order to Multi-cast it? If so and I have e.g. 4 copies of the spell running, do we change the description to 'once the image has been hit 4 times, you have a +9 bonus to defence?

My ruling was no - both because I couldn't get clear rules guidance and again because I felt it was a bit dull.

Comments most welcome!


Q1. I'd agree with you on the no here, it's because such spells usually base the effect off your essential nature, that is, your natural size. Basically the highest one will be the one in effect, but if that lapses and the duration of one of the lowers is still in progress, then you'll only shrink down to that size. (I think there's an example documenting this somewhere in the books, not a clue where)

Q2. I'd say yes here, why not? Basically, all you're doing is adding a modifier to up the size of the effect, though you'll have to decide how much a +1 magnitude should add in size.. as it gets a little vague.
Technically, +1 size mag in ars spells equates to a x10 increase in mass, which in animal/human size (they're on a seperate scale, confusingly), equates to a +3 size. Problem is, that adding +3 size is quite powerful, as you say.. so it might be an idea to say that each magnitude adds only +2 or +1 size to the baseline spell. Up your saga really though, pick whichever matches your power level, there are plenty of spells which could theoretically turn toads into giant versions, or people into giants, so maybe the +3 would fit for you after all.

Q3. Yup, you can.. it's no different from just casting a group version of the same spell, except it'll take you a lot longer. I'd be wary of telling the group about fixing it so they can't prepare for fights though.. .. most magi need to prepare and buff up for fights if they want to stand a chance at survival, they seem quite all powerful, but it's surprisingly hard to fast cast spont a 'stop sword skewering me' spell, especially if there's more than one. Besides, preparing for a fight is only sensible if they have the chance.. wouldn't you?

Q4. Well, technically you can multicast them and have several stacked up.. there's no reason why you can't, if someone dispels a single one, you'll still have the others, so it's another level of protection basically.
However, I don't think it really provides the benefit you seem to be giving it. Basically, what I see as happening in it is, the image is displaced, and then once they've hit it, they know it's a fake.. so they can just start hacking away in the localised area hoping to hit you, which equates to a +9 defense (it's not quite as good as invisibility, as they can see the movements of the image, and use it to at least tell which directions and such you're moving, thus narrowing down your location). Stacking the spell won't help that any, they'll still likely try the same tactic after hitting it once.

My thoughts anyway

Note that the tenfold increase in mass yielded by one magnitude is a tenfold increase in target mass, not in final results - you can affect ten times as many people and/or animals, not make them grow ten times larger.

The Mysteries for Ars Magica 4th Edition (p.144) provides a guideline for shapeshifting spells that change size: "Increasing or decreasing one point of Size beyond a spell's norrmal range adds 5 levels to the spell". It also specifically includes a spell that turns the user into a +6 size giant. Many of the spell guidelines have remained the same or at least similar between the two editions, so I think it's not unreasonable to "port" this to 5th edition unchanged.