Multicasting and Concentration rolls

Over in the ArM6 Thread Direwolf75 and I started a discussion about multi-casting that I think merits a new thread.

I have taken a careful look at the ArM5 rules and the errata. It is far from clear whether any Concentration roll is required, or not, when multi-casting a mastered spell (using the Multiple Casting special ability, of course). The mechanics on page 87 and the errata that amend them don't mention anything about Concentration, so it might seem obvious that there's no Concentration roll required.

However, if you look at the text under Concentration on page 82 it's a bit less clear. The language is a little vague, saying you have to make Concentration rolls if you're distracted. Casting one spell while maintaining another is an example of a distraction.

On the Concentration Table on page 82 is an interesting entry: "Casting another spell" (Ease Factor 15). Now pretty clearly you have to make a Concentration roll if you're casting two spells at once.

The magic question (pun intended) is when you are considered to be casting two spells at once. The language on page 87 under multiple casting says "Each spell must be rolled for separately," which to me pretty strongly implies that mutliple casting counts as casting two spells at once. So, IMS, you have to make that EF 15 Concentration roll when you multi-cast.

I also know from these forums that other players don't require a Concentration roll for multiple casting. What I don't think is that both of us can be interpreting the intent of the rule correctly. So, two questions:

  • What is the argument for not requiring the Concentration roll (does it still hold up after you've seen the "Casting Another Spell" entry on the Concentration Tabel)
  • Regardless of the RAW, which is the more fun and workable way to approach multiple casting?

Oh and one more thing. Is there any circumstance other than multiple casting where a magus can cast two or more spells at the same time? I believe it's possible if one of the spells is fast-cast, but I'm not aware of any way to cast two formulaic spells at the same time, except through multiple casting.

When you multicast are you considered to be casting in parallel or sequentially?

If you are parallel-casting then I'd expect a concentration roll to be needed.

If you are casting sequentially then you might only require concentration-rolls if the spells have a concentration-duration.

I know the die rolls are done sequentially, but if you are required to target and specify all parameters for all of the spells before touching any dice then the spells may well be done in parallel,

I had seen that and had no clear argument either way. The way the rules are stated, they can make sense either way.


Hmmm... You certainly ask some good questions.

As you said, it can get very hard to succeed very quickly, and then the XP spent on getting the Mastery becomes severely devalued unless you also spend alot of XP in Concentration. My reading was always that getting the multicast mastery was the way to avoid the Concentration roll.

Someone suggested disallowing multicast against a single target, with that added i think im fairly happy to stick to no Conc roll.

Fast cast mastery?
Anyway i see i need to reread the relevant sections before i say more about it. :mrgreen:

This is certainly something in need of clarification. Is there anything in particular anywhere that says you CANT cast 2 formulaic spells(without fastcast or multicast) at the same time? Thats where i´ve used the Conc roll.

Since I'm the FAQ maintainer, once we get to a consensus (or a list of sensible alternatives) I will put this in the FAQ.

Well, there's this:

p. 174 "It takes approximately one combat round to cast a spell, unless it is fast-cast. Thus, a magus cannot cast more than one normal spell, or a fast-cast and a normal spell, in the same round. A very fast magus may be able to cast more than one fast-cast spell..."

So that is pretty clear (more so than I expected to find when I started looking).

Hmm... Well i´ve certainly not stuck to that. :mrgreen:

Anyway, thats a rather, no strike that, its a VERY odd text... If a formualic is supposed to take up a whole round, but you can still squeeze a fast cast in with it, that SHOULD mean that if you ONLY used fast cast spells, it should be quite possible to get several off.
And before the quoted text there´s the part about how fast cast is only a "response to another action"... Why should it be impossible to fast cast a spell anytime?
Still, doing a fast cast while doing a formulaic would be my reading of the original intention of the rules. I think...
Oh and if you have a Qik +5 magi, how many fast casts COULD she get off at the same time as a formulaic, and if she does cast like that, should the Conc roll be the same for each or increasing in difficulty, or a higher difficulty based on all fast casts together from the start?

I have a feeling i might HAVE read the above quote before and simply ignored it, and based on the Conc roll table allowed casting 2 formulaic together(requiring a Conc roll but not penalised otherwise) and mostly not penalised fast casts further than they are already(so if you cast several fast cast spells(only), each get the standard penalty but as they´re cast sequentially none needs the Conc roll).
(with Qik +6 as the limit on the number of fastcasts in a round doing nothing else, or half that together with a formulaic, and with each beyond the first raising the penalty to casting total by 2)

I think you really need to reread the whole section on fast casting, p.83, it makes more sense than the short summary on p. 174.

The first words are "a maga may choose to cast a Spontaneous Spell extremely quickly, as a response to an attack or other surprising event" (and the fast casting spell mastery of a formulaic spell allows the maga to cast that spell in the same way), so I would say that the intent is that a fast-cast spell takes no time at all. You just squeeze one (or more) off before (or even after) your normal action, whatever that may be.

The original intention, I think, is simply to counter a spell as it is being cast (the section goes into some detail about how that works and what is needed), but the text also mention reacting to mundane attacks. I see no reason why you couldn't try to fast-cast even if you are not responding to anything, to attack several opponents in the same round perhaps, but obviously if you are not pressed for time there is no reason to try.

As for fast-casting more than once in the same round, well, if you really have the speed and skill, go ahead. You do need to beat your opponent's initiative with a Quickness+Finess stress die for the first, then beat it again with a -6 penalty to your roll for the second fast cast, and the third is at a -12 penalty... and then there is the -10 to the casting score, and the extra botch dice. I don't think you need to add Concentration rolls if the spells are of Momentary duration (unless of course the maga is also being distracted, a distinct possibility in combat), but any spell that is being maintained while you fast cast will call for concentration rolls. If it fails, the maintained spell fails, but the fast-cast spell should still work, if I read the Concentration rules correctly.

I have always thought that if you fast-cast you can squeeze in the fast-cast spell before or after your formulaic spell (even when it is not your turn in initiative, for example as a fast-cast defense), so if you want to do a fast-cast and a regular spell then you don't normally need a Concentration roll.

I say "[not] normally" because there is one example where you definitely have to cast two spells at the same time: if you want to cast Muto Vim to modify another spell as it is being cast.

Now that I look at the Muto Vim guidelines on page 159, I see it implies there that you can cast a Muto Vim spell and another spell at the same time, without necessarily fast-casting the Muto Vim! (It says the time you must fast-cast is when you're casting Muto Vim on an opponent's spell -- suggesting you need not fast-cast at other times!)

So, what I am starting to think is that there are a lot of unclarities and inconsistencies when it comes to casting multiple spells at once. Let me put forward some suggestions I think we can all agree on:

  • If you want to cast more than one formulaic spell in a round, if your SG is generous then you have to cast both spells at once and make the Concentration roll of 15. If your SG is not generous then you can only cast two formulaics in the same round if one of them is Muto Vim.
  • You can attempt to fast-cast as many spells as you want, whether or not you also cast a formulaic spell, but the fast-casting roll gets very hard very fast. When you fast-cast the spells are not cast at the same time, but in rapid succession, so you don't need to make a special Concentration roll (unless for some reason you want to fast-cast a Muto Vim on your own spell).
  • It's totally unclear whether you need to make a Concentration roll to multi-cast. Nowhere does it say that you have to. The text implies in places that each copy of a spell is a separate spell but you cannot really take that to the bank given how inconsistent the rules appear elsewhere (such as in the Muto Vim guidelines).
  • If the Concentration roll is required, then the Ease Factor of 15 is punitively high. Some people may think that would ruin the Multiple Casting special ability, and other people may say "yes, that's the whole point." :smiling_imp:

After thinking this over and tracking down the rules references, I am actually starting to lean toward the side of not requiring the Concentration roll for multi-casting. The reason is that the rules are pretty unclear and inconsistent on this subject, so it would be a mistake to read too much into what they seem to imply. It's hard enough to figure out what they actually say.

Yeah, I think from p. 83 it's clear you can try to cast as many fast-cast spells as you want in a single round. Good luck with that. :wink:

Totally agree with that. If multiple casting involves Concentration rolls, then I don't see the point anymore of choosing Multiple Casting as a spell Mastery. What is the added value ?

Depending on
a) are you casting both spells
b) are you casting a MuVi spell on another spell

In case a), you have to make a Int + Conc roll of 9+ (see Guidelines), so Concentration is somehow involved.

In case b), no such roll is needed.


David clarified this a while ago. Without fast-casting it takes two rounds to cast a MuVi-altered spell, one for the MuVi spell and one for the spell being altered. If I remember correctly, the MuVi spell is cast first, affecting the spell that starts appearing immediately afterward. So, while the book is unclear, David has stated that the two spells are not actually cast at the same time.

Now I'll just have to figure out where he wrote that...


This is pretty odd to me... and counterintuitive.

I would have thought the spells were cast at the same time, or eventually the MuVi one after the spell is it supposed to affect, not the opposite.

And if it has to happen in two rounds, why the hell is a Int + Conc roll needed (if you are casting both spells) ?


IIRC, that's because you're "holding on" to the first spell while casting the second, but my memory may very well be wrong.

I will leave the realm of AM and propose photocopies as an analogy to spells. Printer warms up, postscript is sent, converted to bitmap, fused to paper.

Words, gestures, ceremonial, ritual are vectorial descriptions that help define the image you are trying to release. The more efforts you put into it, the better defined your image will be. Not enough concentration and you cannot build the image.

Fast Cast mastery means you can intuitively cast this spell without having to draw it. Same as a piece of postscript kept in printer memory or a rubber stamp.

Multiple Casting mastery means you keep the image alive long enough to instantiate it twice or more. Same as when you print 2 copies or use carbon paper.

I haven't played in a high-powered combat-oriented saga so I may lack experience here. Considering how easy it is for the SG to overcome a one-trick pony I don't see a need to penalize further casting. And if I was to penalize it I'd go with -5 penetration per extra copy.

Well... I have to say I started out thinking that it shouldn't. But I can see it applied to both Fast-Casting and Multiple Casting, and perhaps even MuVi. I'll have to think more on this.

This really seems (to me) to contradict RAW, so I'd really like a source please?

The MuVi guidelines specifically include a Concentration roll of 9+ to cast simultaneously with the target spell,

I'm looking. For now, consider: where does it say that the spells get faster if you use MuVi spells? Two spells, two rounds. That's RAW. You can spend longer casting spells; that certainly shows up in a few places. So I guess you could consider it two simultaneous spells over two rounds.

Anyway, I'll keep looking for the reference.


So far I've only found David's quote on the boards that the intent was not to be able to cast a fast-cast and a normal spell in the same round. I'm still looking, but the archives are a pain for searching. I'm basically searching through somewhat manually. :frowning:


Meaning no need for concentration roll for casting 2 spells at the same time ever?