Metamagic and simultaneous spell concentration

My current character was designed using influences from Ranulf in MoH. Figuring out how to use metamagic turned up lots of confusion.

The concentration rules in ArM5, p.82 are unclear on whether casting two non-fast-cast spells in a round is actually possible with a high concentration roll.

Previous threads have already addressed the issue:
with a popular conclusion being that the rules' unstated original intent was to have any combo of a standard spell and a MuVi metamagic spell have to be cast in two successive rounds, the casting of the first being automatically "extended" to be released at roughly the same time as the second, because two non fast-cast are simply not cast in a single round and the p.82 concentration table's "Continuing situation" refers only to activities to be attempted while maintaining a Concentration spell.
The MuVI Guidelines (ArM5 p. 159) state that metamagic spells are an exception to the concentration difficulties, their target being 9 rather than 15, making no mention of the 2 spells' relative timing.

Now comes the MoH book, with new spells not covered by these discussions.
Consider Ranulf's Boreal Flames & Patient Spell (MoH p.111 and p.113). Basically, since Boreal Flames is NOT MuVi, it has to succeed a 15+ concentration if cast with Pilum of Fire, but the Patient Spell holds it until a second round changing the Concentration requirements to two rolls of 9+: Once to cast simultaneously Boreal FLames and Patient Spell (I assume that is what is meant by "in conjunction"), and one to keep concentrating on Patient Spell while casting Pilum of Fire.

Thus, MoH implies:

  1. That casting two spells in the same round is possible, even two spells when none of them is an actual Mu Vi metamagic. This begs to follow up with: can you cast two unrelated spells in the same round? Can you take any spell and "design it for combo casting"? If not, what makes a spell legal for combo casting if a Mu(Pe)Ig is alright?

  2. That a metamagic spell is supposed to be cast in the same round as the spell it modifies.

  3. That to extend the casting of a spell over a second round is not a routine free choice, it requires the Patient Spell or equivalent

  4. That the "casting another spell" line in the ArM5 p.82 table DOES refer to two spells cast simultaneously, bringing into doubt what the whole section of the table actually means. (Answering a single yes/no question requires COncentration 12... in the same round as casting a spell? LoM indicates a ten-word sentence as a free action...) The accompanying paragraphs really are unclear as well: what activities are impossible to do while casting? Does the (3 X wound penalty) concentration penalty apply only on the damaging round (in addition to the 15 target?) or for as long as the injury remains?

  5. That maintaining the Patient Spell while casting PoF is a 9+ concentration feat "because the spell is designed for this use", while the Arm5 p.82 table makes this target 12 or 15, depending on how you read it. Should they have clarified that only metamagic MuVi CAN benefit from the "designed for this use" principle? Because Boreal Flames is also clearly designed specifically for use with PoF and doesn't have the benefit...

How do you people understand these issues? How should we read the infamous Concentration table AND its accompanying paragraphs?

I just wish people would stop taking MoH as 'canon' - too many bugs in there, too many house rules.
But I've stated this before.

I agree that MoH has a lot of issues -- I do not think the "quality control" was very tight on its contents. However, it does have the largest collection of spells and enchantments in Ars Magica 5th edition; so it's only natural that a lot of people refer to it. And in the absence of errata, its contents are "canonical", in the sense that they should be assumed as the default starting point to which troupes add their own house rules.

+1. Good sample stuff there and lots of inspiration. Spells should be tsted against the core book before they are directly imported to the game, but apart from that they are quite OK for us. And it is RAW/canon, even if it has issues.


I did not know that was a widely held position on MoH.

So if I understand the three of you well, you would not use MoH content to interpret unclear passages of the core rulebook. Alright, let's work that way. That doesn't make those passages any clearer!

A) How many rounds does it take one (1) magus at a minimum, to cast a PoF and, say, Wizard's boost? 1 or 2?
B) If the answer to A is 2, does it take any special spell, mastery ability or minor virtue to "hold" the first spell for release with the second?
C) If the answer to A is 1, then the Metamagic concentration reduction to 9, is reduced from a 15 "regular" rule... Does this imply you could basically cast ANY two spells in one round?
D) How hard is it to say a few words on the same round you cast a spell? Maintain concentration on a spell?
E) Does the 3X wound penalty apply on the first round of an injury? On all subsequent rounds?
F) Are the p. 82 "continuing situations" to be understood as the unclear "there are things that are impossible to do while casting"? That would apparently contradict the fact that "damaged this round" does have an ease factor for casting a spell...

It takes 2 rounds if the magus wants to cast both spells himself.

The rules are clear that the MuVi spell must be cast first: close to the end of the guidelines, it says "It is not possible, for reasons that Hermetic theorist do not well understand, to use Muto Vim to affect another spell after it has been cast."

So I would say that the MuVi spell must have D:Conc to allow you to affect the second spell being cast, which can only be D:Mom or D:Conc. The D:Conc of the MuVi spell allows you to actively direct it to affect the other spell as it is being cast, which would not be possible with a greater duration (which is "fire and forget").

Things are much easier if you are using MuVi to affect another magus' spell, as you can coordinate to cast the spell simultaneously. Longer durations are then possible.

Not possible is you are currently casting the spell using any Words. Otherwise, I'd go with ArM5 p.82, in the insert under Continuing Situation -- "Answering a simple easy yes/no question", which is Ease Factor 12. With MuVi spells, which are described as easier in the guidelines, I'd go with Ease Factor 6.

Yes, if it occurs before the spell has been completed (based on initiative).

Talking is not possible while casting with Words. Or drinking.

I have been known to say "2, 1 if (and only if) the MuVi-spell is fast cast (which will usually require fast casting.
NB! This is a house rule!

This has been debated. I know of no absolute answer. If the MuVi-spell is fast cast, there should be no problem.

If you want to do anything else while casting a spell, concentration check.
Maintaining concentration on a spell is covered in the rule book (NB! non-concentratio spells are "fire and forget", they do not need to be maintained).
Saying a few words I'd put around 9

Hmm, I don't agree on this one. I'd say that a Muto Vim spell with D:Mom can be used to affect the casting of a formulaic if begun immediately after the Muto Vim spell. There is ample evidence in Arm5 (see e.g. Crest of the Earth Wave or Gift of Frog's Legs) that D:Mom can last up to a round or so, which should be enough to cover an action taken during the next round. I think there is something along these lines written in MoH, but may be wrong.

Made explicit in the errata (please scroll down to Muto Vim Guidelines).

Considering the errata (which I forgot to check, my bad):

Still, I think RAW is clear that only one standard spell can be cast in a round (see ArM5 p.174 under Magic). You cannot fast-cast your MuVi, since doing so either prohibits you from completing the casting of your target spell (if cast before), or is completed after (meaning you cannot change it, as per MuVi guidelines).

And since you need to have your MuVi last for as long as you cast your target spell (takes a round, which is longer than Mom), then you need to cast it before, with D:Conc (and a successful Int + Concentration roll of 9+), in order to be able to target your next spell.

You could, in theory, also cast your MuVi spell with D:Mom, and immediately fast-cast (through mastery) your target formulaic spell. The two would then occur in the same round.

Note that this is a severe interpretation of D:Mom as being shorter than a round.

A slightly less severe interpretation would allow the MuVi spell to endure until the next round, allowing immediate casting of the target spell. Still, this is still happening in 2 rounds if only a single magus is doing both spells.

Much as I'd love to agree with you, D: Momentary is mentioned explcitly in the errata as sufficient (well, it was earlier today, and assuming it hasn't changed...)

Actually, the errata is not quite that definitive on that. It says "This means that a Muto Vim spell must have a duration at least as long as the casting of the target spell, but need not last for as long as the spell itself. For normally-cast formulaic spells, a Momentary Duration is sufficient, but if the casting time is longer for any reason, the Muto Vim spell must also have a longer Duration; Sun is sufficient for any practical Ritual."

That may be interpreted as the Muto Vim being cast at the same time as its target spell (i.e. 2 magi are involved). If you are casting 2 spells, one after the other, the first's Momentary duration may not last long enough to cover the casting of the second one.

As I wrote, this is a severe interpretation of the Mom duration, and I would certainly be open to the less severe interpretation that allows consecutive casting with D:Mom.

Emphasis mine.

How much more explicit do you want it?

Did you actually read what I wrote after that? :unamused:

Momentary duration is fine if there are 2 casters, no problem.

Momentary duration may or may not be sufficient if there is only 1 caster and the spells are being cast in succession. The errata can be interpreted in either direction. I'm leaning in the direction that it is sufficient, but it could be interpreted that it isn't.

Note that all the examples given in the MuVi section are Duration: mom - including Wizard's Communion, which is specifically designed to be used with groups of people who are casting the same spell (ie, rituals). Of course, it also says that it does not perfectly fit the guidelines of Hermetic theory - but I usually read that to mean the actual wacky effects of Wizard's Communion, rather than the duration.

I've always interpreted it that they are cast in the same round (due to the "both spells must take the same time to cast" idea)- and that in terms of game balance, the required concentration check was enough to keep it from being too much of a game-breaker.

Momentary can last up to a round after the casting, so that is sufficient to allow casting the MuVi spell one round followed by the other spell the next. This would not violate the 1 spell/round rate (excepting Fast Casting stuff). I don't know how casting two spells in one round would be consistent with the rest of spell casting (without Fast Casting stuff).


I'm sorry, I was trying to be polite and not ask if you'd even read the errata you'd been linked to.

Yes, I read it. Yes, That's in many ways how I want it to work but it is not how the errata explains it.

It is a big enough book that everyone can find something that they do not like, there are a few things that bother me. I've read two or three times that there are folks who think it's poor as a whole (but I don't remember the authors it could have been Tellus saying the same thing several times). I've never seen anyone list their issues with it. Certainly it had as much play testing as any other book.

I can tell you with certainty that there are many passages in magi of Hermes that were specifically put in to make unclear passages in the rulebook clear.

page 174 of the rule book tells us, (issues with the conjunctions aside), that you can't cast two spells in the same round unless both are fast cast.

page 159 says you need to make an int+ concentration roll to cast a Mu Vi spell on your own spell. There is no mention or even text that appears to hint that such spells need to be cast in successive rounds with the caster "holding" the target spell while the muto vim spell was cast.

The concentration table on page 82 talks about casting another spell and, on a different line, it talks about maintaining another spell.

These three passages are contradictory. There really is at least one mistake in there.

I find it very unlikely that two rounds for muto vim spells was the original intention. If that is the model of how things work that you have in your head, then you don't write the muto vim section like it is written. (A counter argument that can be made is that the muto vim guideline text box is a slightly edited version of the fourth edition section. None the less, if you want to communicate the idea that it takes two rounds to cast a muto vim you don't leave it to context).

It seems much more likely from the muto vim guidelines that muto vim was intended to be an exception. I can easily imagine that MuVi spells were forgotten about when the text in the combat section was being written.

That leaves line on the concentration table

For the answer to be 2 you have to assume that the combat section is meant to be more descriptive of muto vim than the muto vim section.

People have taken it to mean that and there have been discussions on this board about it and in my games. I can only guess as to the author's intent. I can tell you that the line doesn't doesn't appear in the "distraction tables" of prior editions.

Boreal flames indicates specifically that you can not cast two spells in a round unless one of the spells was specifically designed to be cast with another spell, like the muto vim spells. As the author of boreal flames I can tell you that this is intentional. It gives meaning to the concentration table entry while showing that you cannot cast any two regular spells in the same round.

The concentration table on page 82 defines this.

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OK, I just re-read it. Not to nitpick, but it says that only one of the two has to be fast-cast.

So, if I understand you well, you do interpret all those lines from the lower half of that table to apply to casting a spell, not just to maintaining one? "Casting another spell" could be in addition to maintaining the first one, your emphasis on ANOTHER does not necessarily mean that we are discussing the same action with two spells, only that two spells are involved... Unless this is a subtlety of English I am wrong about? Can you say: 'I'm eating an apple and keeping another one for later"?

Hmm, interesting. So if I understand your intent as an author:
1- Casting two regular spells--- impossible at any concentration
2- Casting one regular spell and one "designed for conjunction": Con 15
3- Casting one regular spell and one Mu Vi "designed for conjunction": Con 9

So what are the criteria to design a spell for conjunction? Does it increase spell level? Can a Magus add in that detail upon inventing any spell? Boreal Flames is targetting a fire, not a spell, so you cannot use "targetting a spell" as a criterion. Can such a spell then be used ONLY in conjunction, or can you retain the choice to use it independently (assuming its effect is useful, like a momentaneous perdo of some aspect of a form)?

Does it? Only if you take the lower half of the table to apply to both casting and maintaining spells. In that case, what lines in the table does this paragraph in the accompanying text refer to? :

That's the issue with the conjunctions (OK now that I've found the quote I see it isn't about conjunctions). There are two ways to read that passage:
"Thus, a magus cannot cast more than one normal spell, or a fast-cast and a normal spell, in the same round."
IMO you should read it
"Thus, a magus cannot cast
A more than one normal spell or
B a fast cast and a normal spell in the same round"
that is to say
"a magus cannot cast ... a fast-cast and a normal spell, in the same round."

But you can also read it
"Thus a magus cannot cast more than
A one normal spell or
B a fast cast and a normal spell in the same round"
that is to say " a magus cannot cast more than ... a fast-cast and a normal spell, in the same round."

There is another entry on the table for casting a spell and maintaining another spell.

that was my intent.

That's never been dealt with. I think that you should use "targeting the other spell that you cast that round" as a prerequisite to keep things reasonable.

I miss read your question.