Fast casting vs other mages.. better to be second?

(Well, now you've made up for it. :wink: )

And I think the elegant solution is both obvious and not against the rules - that "going first" doesn't preclude fast-casting later in the same round.

(Phew!) :laughing:

Well, you can "degage"(sp?) (evade/elude/disengage) a block.

A fast-cast is not necessarily analogous to a block or parry - it's analogous to a magical flinch. What that flinch does, whether defensive (perhaps a block/parry) or offensive (a quick stop-thrust) or something else is up to the caster.

First, let's disabuse some folk of the wrong model of how fast-casting works.

In Ars, "1 combat round" is an undefined amount of time. There is an approximation ("about 6 seconds"), but that's not a rigid Olympic-timekeeping-quality amount. And each round is then abstractly broken into initiative phases - these are not even "fractions" of the round, but undefined "your turn" and "her turn" and "their turn". Initiative determines "who goes first" - and fastcasting doesn't change that. The fast-caster is always reacting, never "jumping back in front" of the action.

Let's say Mage A rolls a "7" and Mage B rolls a "5". Mage A acts on 7 - Mage B can try to fastcast, but that will never occur faster than the initiative of the "surprising event" being reacted to.


In our example, Mage A goes first, and he casts a spell, or swings his mighty quarterstaff down on Mage B's head - or maybe he's unconscious and the "surprising event" consists of him falling out the 3rd story window down toward Mage B - all same same. Mage A's action has occurred on Initiative 7.

Now, Mage B can fast-cast as a reaction to that event. The event is already happening - the PoF has been cast, the quarterstaff swung, the body falling - can't retro it back to not-happening. What can be done is to react to stop that effect from landing (or otherwise avoid it), or (as suggested above) get in a quick retributive strike before Mage B suffers the inevitable effects. (Maybe Mage B has a ward vs. flame, or a Ward vs wood, or a Ward vs corpus - nothing says the fast-cast has to be defensive (even if the rules "imply" that).

So now we assume Mage B makes their Fast-cast roll*, beating a difficulty of Mage A's initiative. Mage B's spell is spontaneously cast* as the first spell/attack/body takes effect (unless multiple spells are being fastcast/etc.) This can be construed as a new "surprising event" - nothing that I can find in the RAW says that once you take a turn or cast a spell you can't then Fast-Cast in response to a new "surprising event".

(* more on all this dice-rolling later, so hold that thought...*)

The advantage Mage A has is that his fast-cast spell is against an easier difficulty factor, since Mage B rolled lower initiative than Mage B. Keeping in mind the last paragraph, if Mage B blocks the spell - that's not all that surprising, no fast-cast for Mage A. If Mage B sends a spell toward Mage A, that is surprising - and Mage A can try to fast-cast to avoid that attack, same as Mage B did Mage A's attack "before" Mage B could even act. Fair is fair.

More, if Mage B misses that fast-cast roll (quite possible!), they are done casting spells for that round! They can do something else on their initiative, but not cast a spell. (Some SG's require that all combatants declare their intended actions before determining initiative for the round - makes things feel more like "combat" and less like a chess game.) And if they do something "surprising", then Mage A has the option to... fastcast, as a response to that. (And unlike Mage B, Mage A doesn't care if they lose their ability to cast spells for the rest of that round - they've taken their action!)

And all this fastcasting is "with SG approval" - I hope few SG's would allow a mage to claim "surprise" that his target did/didn't die from the first spell, or "I'm surprised that I'm still standing, so I'll now fastcast...". That's not in the nature of FC'ing. (I would even suggest that it has to be SG-invited if not SG-approved, never assumed by the Player as an option they always have.) This gets back to what "an initiative round" is - a fast-cast is not a "half-action" or a "surprise attack" or a "quick action", it's a way to allow a mage to be magical when they really need to be. If they don't have anything legit to react to, initiative and actions - and spellcasting - proceed as normal.

(If magi in your Saga are always trying to FC every combat round until they fail their roll, sending off random spells at whim, think about what I've said above!)

I'm not even sure there is a "technically" needed here - that's how the rules read, and it makes sense. (Or, at least, the opposite interpretation makes far less sense.)

  • Has a potential to - this is far from guaranteed! (And here we are getting back to the notion of "assuming Mage B makes all the rolls" to fast-cast...)

First, the mage has to beat Mage A's initiative, and that roll has already proven to be higher once (so odds are it's a decent roll - not always, but more often than not.) For these tenuous additional spells, each takes a cumulative -6 to that difficulty roll - that's more than an average d-roll, so that's a serious knock. Take a LOT of Finesse to make up for that.

And then the spell has to be Spontaneously Cast at -10 to the Casting Total - and only the rare archmage could cast such as non-fatiguing and thus guarantee that roll. (And with 2 extra botch dice, it's not something done lightly!)

And Mage A can always try to counter any "surprising event" these new spells may create with a FC roll of their own - and against an easier ease factor.

To me, this creates more of a feel of intensely fast parry-riposte spell dueling than any "paradox of time" - each mage is seeing what is happening and countering it (or praying/hoping to), until one fails. And then, if the other can make yet another roll with the added-6('s) of penalty, they keep going.

The procedure that I would use, which I think is consistent with the RAW (and happily seems to be consistent with Cuchulainshound's response), is as follows (which is long):

Magus A has an Initiative Total of 7.
Magus B has an Initiative Total of 3.

Magus A tries to BoAF magus B.
Magus B tries to preempt this by teleporting away as a Fast-cast. Magus B has to make a Fast Cast Speed roll against an Ease Factor of 7 (which was A's Initiative Total).
Magus B makes the Fast Cast roll.

Now, Magus A notices that Magus B is trying to Fast-Cast something. So, he decides to Fast Cast a response to this (say a Rego Corpus effect to paralyse Magus B --- so he has to cast without gestures). Magus A has to make a Fast Cast Speed roll to see if he can do this. The Ease Factor is 3 (Magus B's Initiative Total).

Now, Magus B wants to Fast Cast in response to this, by using Perdo Terram to open up a pit underneath Magus A. He has to make a Fast Cast Speed roll, against an Ease Factor of 7 (A's Initiative Total), but has a -6 penalty to the roll because it is his second Fast Cast. Magus B fails this roll and can no longer make any further spell casting rolls. So Magus B, can't make any more Fast Casts attempts and he loses his normal spell opportunity at Initiative 3; however, he can choose to still cast this Fast Cast Spell (Perdo Terram) at the end of the round if he wants to.

Magus A declines to make any more Fast Cast attempts (at this stage).

Now we step back through all the pending effects.

First we roll for Magus A's Rego Corpus effect. He fails the Casting Roll, so the effect does not occur.
Next we roll for Magus B's teleport effect. He makes the Casting Roll, so the effect does occur.
Now, Magus A can now complete the Casting Roll for the BoAF. He chooses not to do so as the target is no longer present.

Summary: it is complicated, but it is better to win Initiative; because it means that your opponent has a higher Ease Factor target for his Fast Cast Speed rolls than you do. So, all things being equal, he will have a harder job of preempting you.

Perhaps that's a bad example - one cannot fastcast without gestures. Or, actually, that's a perfect example for what I'm suggesting...

But this would not be perfectly in keeping with my model - in my version, any fast-cast is in response to something that has "already happened" (even if lightning quick in response!), and so Mage B would already be gone.

One responds to the spell effect, not to the beginning of the casting. That's where winning initiative (the original initiative) has its advantage.

Some of your other cause-and-effect examples are similar. Fast-casting is not like Magic Cards where one card stops another from being played and so is discarded. It is in response to a card having been played - that first card is already on the table, and all you can do is try to negate it with a card of your own, which also gets played - and then can be negated in turn. The cards are played, the spells are cast - this avoids paradoxes of time and action, where a spell is allowed to be cast before another spell, but initiative was already lost, so how can it be before?, etc etc.

So, a mage can't fast-cast to stop someone from casting. That spell was "first" in Initiative (or in Fast-casting initiative, to stay consistent), and all they can do in response is deal with the spell (or target the caster if they don't care about the spell!).

(Edit - as an afterthought, if a SG finds all this potential for multiple casting too confusing, they might want to rule that any fastcast in response to another fastcast triggers the cumulative -6 penalty. This would prevent 4 magi from each fastcasting at no penalty around in one huge conga-line. If you're going to react to something that is already reacting to something, you'd better be fast!)

So, it stops the other person from Fast Casting, if it goes off first.

But casting takes time.

So, I don't see why you can't react to the beginning of the casting instead of the end? Sure, you are less certain about precisely what you are reacting to, but that is only problematic in the sense that your Fast Cast response might not be particularly appropriate if you guess wrong about what your opponent is doing.

I know (and I'm not saying my model is perfect) - but if it goes first, then we're back to paradoxes of initiative and advantage.

Yes, but an undefined amount of time.

And if one can go last in initiative, and still (in theory) cast a half-dozen fast-cast spells, and not start this process "before" anyone else... how much time does it take? Not very much, I'm thinking...

The FastCast section talks solely about responding to the spell itself and the spell level. I'm assuming that a mage has only just enough time to see the gestures - at which time the spell is effectively already on its way - and Mage B can then just barely react with their fast-cast effect before that first spell hits.

It's not that I can't see your view of how it might work - I can, all too easily. It's that I don't think(?) that FC'ing was ever intended to stop the casting, but the spell itself. Otherwise, fastcast could just kill the mage with the higher initiative before the spell is ever cast - and we're back to "What was the point of winning initiative, again?" That's why all the paragraphs talk about determining the T/F of the spell, and comparing the level of the FC to that of the other spell, etc. - and never for a moment contemplates that the FC will just cut the other caster off before the spell is completed (the otherwise obvious and preferable ploy!) Why would one ever bother with determining T/F/etc. when you can just preempt the caster directly? If the rules don't address it, don't even hint at it, and go on at some length about the spell itself rather than the casting, I'm guessing it's just not an option.

That, and it completely avoids the paradox of the OP.


Now that seems wrong. Both Ease Factor should be 7. The reason should be obvious if you think it through.

Or should the second be (7+6)? Mage A already acted on 7 - should this be that much more difficult? :confused: <not convinced, just thinking out loud>

(edit - fixed typo - thx T)

Ease Factor - you mean (7+6 = 13), and no I don't think it should be that much harder.

If I was to create a mechanism for fast-casting, I would consider that the action occurs at Time 7 in this case (the Initiative Total) and that you need to beat that time by 3 to fast-cast a response (Time 10 = EF 10), to react to that fast-cast you'd need the same difference (Time 13 = EF 13).

Of course, it is more cinematically pleasing not to penalize the initial fast-cast, so going {Time 7} -> {fast-cast EF 7} -> {counter-fast-cast EF 10} would be nicer I think. Note that in both cases, if you counter-counter you get the expected +6 for 2nd fast-cast.

Note that Concentration seems to imply you cannot fast-cast while casting another spell, which could mean that counter-fast-casting a spell at a fast-cast directed at your {action: cast a spell} would abort it.

Just use LoM optional rules that I find really interesting for this because they get rid of the oddly defined fastcast by the core rule book.

You roll initiative.

Fastcasting is an interruption to any action; you can interrupt yourself. TO succeed you must overcome an ease factor called "action priority total" rolled by your opponent. If you do, he can interrupts your interruption, using "action priority total" of your fast casting.
Any further fastcast besides the first are at -6 penalty initiative.

if A wons the initiative by luck, B is likely to take it back with a fastcast.
If A is the faster magus of the tribunal, nobody can steal him initiative unless he botches. A magus who is designed for this purpose has like a constant base of 30 ininitiative: he is not often beaten in initiative.

Maybe because I'm used to Magic the gathering where using the pile is quite common did I have no problem with that rule.

After doing some thinking, I wanted to come back to this - I hadn't said it just to be politik, I meant it, and at the time wasn't even sure why I shared that feeling, why it did make a type of sense, where it came from and then why it still wasn't approp w/ AM. And I figured it out.

In another, early Fantasy RP Game, one that many of us may be very familiar with and perhaps started in, a spell can indeed be interrupted and thus "lost". There are specific rules for how that can happen. The "spellcaster" is defined as casting the (typical) spell throughout the entire combat round - they have to be a'shuckin' and a'jivin' for quite a while, and any attack or unexpected interruption can have that effect. And for many of us, that is the image of "casting a spell" that we carry with us into other games.

But there are no such rules in AM. A grapple, an attack with a weapon, an angry mob - if the mage is not already restrained/grappled, the spell is not "stopped". There is no mention of how one might do that in the Magic section, nor in the Combat section, nor anywhere.* There is no stated or implied "length of time" that a spell takes to cast - snap, it's done, tyvm kkbb.** So fastcasting to "interrupt" another casting is introducing a brand new concept into the core rules (and should then be mirrored into normal physical combat, so someone standing next to a mage, or with a ranged weapon, might do likewise, if only accidentally - which simply cannot happen RAW).

(* The Concentration Table, p 82, describes penalties to a Conc roll to cast successfully - but nothing more, and that is, apparently, only if damaged before the caster's turn in Initiative. Nothing implies an "interruption" is possible.)
(** In fact, the fastcast rules imply that the time is much closer to "snap" than to anything else, or certainly can be!)

So, for someone new to RPG's who reads the AM rules only, having a spell "interrupted", by any means, is simply not something that they ever expect to be able to do or see done in the game. It is a concept that is, literally, alien to Ars Magica.

Now, if a SG or Troupe wants to adopt that "other RPG's" paradigm into AM, to import this "alien" concept from outside, that's fine, and perhaps a good thing - after all, there is a drama to stopping an evil wizard who is in the very middle of casting a spell. It's a diff model of how the world works, but not necessarily a bad one, and one that many veteran RP players are long familiar and comfortable with. Just be aware of what it is, and it is not RAW, not even a little bit. :wink:

Well, I was thinking of multiple magi, each in turn trying to fastcast to react to a fastcast before them and all before the next Initiative - that seems... odd. (And, yes, 7+6 - thx, fixed.)

"30"? From {Quickness + Stress Die}? Or is that a diff formula, one from LoM?

I'll have to look at lords of magic, because we're back to another pickle.

Lets say what you are saying is correct, about the lack of interruption, and it happens at the same time. Now here is the pickle, magus C.

Magus A init 6.
Magus B init 3.
Magus C init 8.

So as per above, but both A & C wanna try to kill B. B fast-casts beating an ease-factor of 8, so even by your interpretation (or RAW or what have you), he's not going before, Magus A, because he was fast-casting at the speed of Magus C.

So, again, the non-RAW problem here is Magus B is capable of fast casting and beating Magus A's spells handily, however, by RAW, he can only do so if there is a 3rd party present that allows him to have a higher fast cast difficulty?

I'm confused. That is exactly the way it gets handled in that other game (at least 3.0 & 3.5; can't say for 4) - a Concentration roll when damaged is dealt, etc. So it feels to me like the difference you're citing is basically the difference between "if the magus is damaged while he is casting" and "if you damage the magus while he is casting." Am I missing something?


While I like the comment about blocking a block, and I do think that is the basic intent, we still end up with a problem when we extend things. For example,

1a) You can avoid an attack with a Fast-Cast Wizard's Leap. If that is a gaze attack (Medusa), then you can avoid a gaze with a Fast-Cast Wizard's Leap. If you can avoid a gaze, then you can Fast-Cast against someone looking at you, not merely attacking you.

1b) You can avoid a spell to drop a wall around you with a Fast-Cast Wizard's Leap. The same applies if the wall is just created in front of you to block a doorway. At that point a spell to close and seal the door is basically the same. So you can Fast-Cast Wizard's Leap in reaction to the door being closed. If that's the case, why not to it being opened (which could be argued directly anyway)?

  1. You can Fast-Cast a jet of water to stop a dragon's breath. What if that dragon always breathes fire? Then you can react to it breathing with a jet of water. Could that jet of water not potentially cause damage? Doesn't that mean you can Fast-Cast an attack in response to another's breath?

So although I like the blocking a block comment, due to the nature of Fast-Casting not simply being blocking, we run into trouble. I don't think we can find a good cut-off. I think we're safer saying you can Fast-Cast in reaction to anything, but make sure we interpret that Fast-Casting in a reasonable way. (I'm out of time right now.)


Yes, you're missing the difference between damage "in the same round, before the spell is cast" (which is how the AM rules read) and "during the casting of the spell", a concept which doesn't exist in Ars*. I think you're (understandably) projecting the understood model of spellcasting from "that other game" onto Ars. Remember what's on-topic here - the question of whether one can FastCast to "interrupt" the casting of a spell, or not. In Ars, characters either attack before or after another - never "during".

(* Your "a Concentration roll when damaged is dealt, etc" doesn't exist in Ars (for casting spells) - it's rolled after the damage is deal, and only if the mage tries to cast a spell that round. Maintaining a spell w/ Dur:Concentration is a diff matter, and not relevant here.)

In that other game, spells take "1 round" to cast - that's the entire round* until the caster's initiative, so the caster is casting during the entire round up to that point, and so any attack in a previous phase interacts during that casting. Physical attacks can clearly occur while the casting is in progress, and there are rules and tactics that specifically involve that interaction.

(* or was back before the most recent incarnation. If I have the details wrong, forgive, but the principle diff still holds.)

In Ars, nothing says the caster has already begun casting during previous initiative phases, and nothing says that the casting continues after their Initiative phase. The Concentration table says "in the same round" - and (since Concentration rolls are not retro-actively failed on a later Initiative phase, after the caster's) that interaction can only be applicable if the damage/attack occurs before the caster's initiative, which is before he starts/finishes casting.

The spell is cast on initiative X - by the Rules, nothing needs start to happen before, and nothing continues to happen after. On X, it's started and completed. We've already established that Fastcasting cannot happen before or even simultaneously with that, so it must happen after. So, since a Fast Cast occurs after that initiative (but before the next) - the spell is already done, so the FC can interact with the spell itself, but not the casting of it.

Let's look at the issuen from a diff perspective. By rule, fastcasting must always be done with loud voice and bold gestures. If a mage has already been grappled or restrained (interfering with the gestures), then no fastcasting. But there is nothing in the rules that describes how a physical combatant can disrupt that as a "reaction" to the casting. Yet that is - or would be - an important part of combat, one worth at least a comment. So I have to conclude that it's not possible. And since the rules on FC'ing only address "spell vs. spell", similarly I think it's safe to conclude that fastcasting can't do it either.

It's something people are assuming is possible because it was possible in a game they played previously, not because the AM rules even remotely suggest it. :confused:

I'm not sure any of those are a problem. A mage can, if the SG allows it, fastcast to react to anything after it has happened. (The more I think about it, the more "surprise" is a painfully subjective standard, and so a badly flawed one to try to apply as a yardstick.) A wizard can react to a Medusa's gaze - but the gaze has already happened, and if the "reaction" doesn't defeat it somehow, it's statue time. Alternately, a wizard could equally react to a mundane's gaze - far less lethal, but still possibly a valid "event" to act as a trigger. A wiz can react to a door being opened - but can't prevent the door from being opened if that's the stimulus they're reacting to (altho' they could slam it shut again/etc.). The reaction can, in fact, be an attack rather than a defense - that's up to the wiz, but it doesn't stop the other attack/action from having occuring.

And, yes, taken to extremes, a wizard could fastcast in reaction to a spring breeze or a fluffy cloud on the far horizon or almost any stimulus - but that's a matter for players to self-regulate, or for the SG to rein in if they don't.

Ah, I see now. Thanks for the clarification. I do disagree a little. The damage would be in the round up to the casting, but the ArM5 rules don't specifically read that way for interruptions in general. They actually read closer to the latter. "A maga must concentrate in order to cast a spell. If she is distracted..." (p. 82) The problem, if I understand you correctly, is just what "during" or "while" mean in this context. On page 81 of ArM5 it says "It takes only a few seconds to cast a Formulaic spell," which is a bit vague. Presumably regular spontaneous magic is the same, though that doesn't seem to be stated. Ritual and Cermonial magic are pretty clear. For Fast Cast spells it's done "extremely quickly," which is again pretty vague. I think it's pretty clear you can attack someone while they're doing Ritual or Ceremonial magic. For the rest it's not so clear, though I think it can be shown mathematically that the rules do imply during.

I'll also say I'd have to look in LoM for more clarity on this one.

I ran out of time before, but I think I would tend to go in the same direction as you. I would generally say the spell to which you're reacting goes off before a Fast Cast defense, but the Fast Cast defense goes off before the first spell lands. This puts the Fast-Cast defense essentially at the time of a block or parry, after the attack has commenced but before it has finished arriving.

The point of my examples, though, I think was missed. If you can react to a breath, or a look, then you can certainly react to a word or the rotation of a head. Could you not then get the Fast-Cast spell out before the eyes are aimed in your direction by reacting while the head is still turning? Could you not react to the first bit of air used for the several words in a spell and thus get the Fast-Cast spell out before the enemy caster? Etc. Meanwhile, this defense could be something offensive, too. So this all seems to get a bit dicey.


No, if you read the rules, the Ease Factor for Fast Casting is the Initiative Total of whom you are reacting to. It doesn't matter that magus B is reacting out of sequence, his Initiative Total is still 3, so that is what magus A needs to beat.

This is (one reason) why it is a good idea to get a high Initiative Total. It makes it harder for other people to Fast Cast to interfere with what you are doing, even when what you are doing is Fast Casting yourself.

I would agree that is the usual state of affairs, but I see no reason why a magus can't (if he wants to) react to the beginning of a normal spell and decide to rush through a Fast Cast defence (or offence) prior to the original caster completing his spell. The Fast Cast spell is by definition "cast quickly". So, even if we don't really know precisely how long it takes to cast a spell normally we do know that a Fast Cast spell is quicker.

I agree. There should not be a definitive cut-off. It's too complicated and messy for that. I think it is better to let characters attempt to Fast Cast react to anything they like and adjudicate on a case-by-case basis whether something is possible. In actual play we do have a troupe and a storyguide available to make such judgement calls.

That may be RAW but it is still wrong. For instance, if mage C fast-cast in response to mage A, his EF will be 7. But if he fast-cast against a successful fast-casting mage B, his EF will be 3. Now the absurd part is that in both cases his spell is an answer to A but he can piggy-back on B to make it easy.

Now that I have a little more time, I think this is implicitly incorrect by the rules. A round takes roughly 6s, as stated a few times in the rules. Meanwhile casting a formulaic spell takes a few seconds. Let's let ti be the time taken for the ith magus's spell. For a spell to take at least 2s, really the minimum for "few," we get ti>=2s. Let's say we have ten magi (five pc's and 5 npc opponents) casting formulaic spells in the same round. For the above statement to be true we have t1+t2+...+t10<=6s. Using the minimum time we get 10s<=t1+t2+...+t10<=6s, meaning 10s<=6s, which is false. So at least some of these spells must happen during the casting of other spells.


If C is fast casting in response to A then his Ease Factor will be 7, which is A's Initiative Total. If C is fast casting in reponse to B then his Ease Factor will be 3 (as that was B's Inititative Total).

The only way that C can "piggy back" is by the player lying about what his character is doing (i.e. saying he is responding to B, when he really means that he is responding to A). If your problem is that players are lying to the troupe about what their characters are doing --- then no rules can help.

I won't try to deny that, but I also remember a disagreement about some other rules that I claimed were "clearly implied" but certain others refused to acknowledge since they were not explicit.

Yes, that one passage suggests that it (usually?) takes several seconds to cast a spell (paraphrasing here) - but that timing is then completely ignored in both the Magic and Combat sections, and it would/should have a significant impact in both - yet we don't see it anywhere we'd expect to. So if it's not important and not recognized... where does that leave us?

Perhaps with an open door to houseruling as we see fit - but that's all I've said all along - that it's nowhere in the RAW. One could cut and paste different unconnected and unsupported comments, comments that may be no more than throw-away "colour", into applicable (house)rules that radically alter what the rules give us (which is, perhaps, a bit on the lean side), but if the game itself didn't bother to, and it works* as written... :confused:

(* And it does work as written, it just doesn't invite spellcasting to be physically interrupted.)