CrIm Formulaic Spells - How Specific?


One player is in the process of creating a master of illusions and the topic of formulaic CrIm spells came up, as one might expect it would. We have not been able to come up with any sort of agreement about how such spells work, so off to the forums I went.

Poking around I found the thread,Reforming Spell Guidelines for ArM6?, which has a discussion of formulaic illusion spells. My take away from that topic is "troupe's discretion" since the rules seem a little vague on the matter. My current thinking is that extra magnitudes result in much more flexible spells and for highly specific spells a 1 magnitude reduction is in order. And fine tuning the effect of the spell (e.g. the colour of the shirt) is a finesse roll. The issue is, of course, what's the baseline.

If you would indulge me, some feedback from more experienced Ars Magica practitioners on the following spell concepts would be appreciated. Note that all these spells can be cast spontaneously; I am using them merely as a point of discussion.

  1. A spell to create an illusion of a bodyguard -- Can the same spell create 2 bodyguards? 3? Instead of appearing to guard someone, could the spell be used to create the illusion of someone playing chess?

  2. A spell that shows two people walking -- can the same spell show two lovers walking hand in hand or two guards walking and appearing observant or a rich person and his/her spouse out for a stroll? How about two people running away?

  3. A spell to create a cat -- could this spell also create a dog or pig or mink? What about a bird? Or a toad?

  4. A spell to create the sound of footsteps - Can the spell create the sound of footsteps on any surface (stone, wood, snow)? Can the spell make the footsteps sound like they are approaching or receding? Can the spell make the sound of variable number of footsteps or just a specific number?

  5. A spell to create clothing - Can it create anything from hosiery to a doublet?


I'm probably going to sound like a broken record, but Finesse is your friend. I think that you, as the SG need to establish target ease factors for illusions. The spell will always create the original thing it was designed to do, but if you wish to vary the thing created, it's time for Finesse. Creating a duplicate of a person that passes for a person, including the voice and smell (because back then people did smell, whether due to perfumes, BO or both) as well as the look is going to require a really high EF, IMO.

  1. Creating an illusion of a bodyguard is a level 25 effect in canon: Phantasm of the Human Form. Creating two would involve multiple castings and/or a T:Group target, which would create 10. They would all be identical, I think it's left unsaid, but worth noting that the individual created is the same every time, although I might make allowances for different clothing, armor, but the face looks the same. In order to vary that, you have to make a finesse roll of some suitable difficulty. I think it is also important to indicate which senses are affected in the description of the spell, Phantasm of the Human Form does not do it. I think it's sight and sound. The +1 intricacy is for making intelligible speech, so you could direct it to say something, but, of course, you have to hear it, and there would be lag.

2)Given that Phantasm of the Human Form allows some direct, unspoken commands, I don't see why it can't do what you ask. Handling multiple illusions, and feeding them commands at once might require some sort of concentration command, or you have to do them sequentially.

  1. Phantasmal Animal, how "believable" the animal is should probably be based on a finesse roll of some sort. I would allow one standard design as part of the spell, and other animals need the finesse roll.

  2. The guideline is create an "image" that affects a single sense, so you can create disembodied sounds, or you can add them to your spell, it's just important to note that the design of the spell should include the senses affected. I would say the degree that one could imitate those sounds would be a finesse roll. You're continually shaping your magic to the environment.

  3. Yes. Again, the spell is designed to create some image in particular, but you need Finesse to alter it. Clothing is also a really complex image if it is actually worn. I imagine that there would be clipping similar to what I've seen in moddable video games. Elbows and knees might break through the illusionary clothing, depending on the recipient's actions. This is somewhat easy to fix for the magus, if he's wearing it, but becomes more difficult for others. Or something.

One house rule we have in my campaing could be useful.

We introduced a new mastery "Flexible shape". This allow the magus to give the shape he wants to a spell normally bound by simple shapes (like a wall, a cube or a circle). This will require of course a Finesse roll to achieve the desired shape. It is still limited by the spell range of course.

As Jonathan. I would also remind you that if there is a variant with T:Group, you do not need to have 10 copies. It is up to 10.
Bumping magnitude for extra complexity, distinctive characteristics, semi-independant behaviour is recommanded. It still need to be a group, so you cannot use the same spell to generate three grogs fighting a troll with three cheerleaders by the side.

For complex scene, you should consider Room so characters seem to interact with the environment.

For point 3: Phantasmal Animal (p144) allows to create any animal or beast up to the size of a pony. So unless a mage insist to invent a spell which will create only illusiory cat, there is quite some flexibility. It is still limited to what the mage knows or possibly can imagine.

Point 4: Any sounds you want. You can also play with MuIm so somebody walking on snow makes sounds like if he was walking on dry branches, or eggs... Pe Im can make somebody completely silent (which makes spell casting challenging...) and PeIm on touch sense will make very difficult to keep balance, hold objects and overall interact with your environment (no more sense of heat, cold, no sense of pressure applied, possibly no sense of pain as well.

Point 5: Same as the Phantasmal animal. For clothes relatively tight fighting, I will not require extra magnitude (it follows the body movement), but for items like cape, scarf, gown and other similar stuff adding an extra magnitude for intricacy and complex movement sounds right.

All in all, Finesse is a must-have for illusionist and Concentration is not bad either.

I would suggest looking at the published examples to see how much flexibility you can get out of a spell.

In this regard, I think the previous two posters are a bit too restrictive about how much flexibility to allow. In particular, I don't think that handling an illusionary sage's flowing robe is any more difficult than handling an illusionary damsel's flowing hair; or that a spell that creates an illusion of a man always creates the illusion of the same man (after all, a spell that creates the illusion of an animal can create the illusion of any animal. Yes, a spell to create an illusionary animal gives you much more flexibility than a spell to create a real animal; that's one perk of dealing with illusions.

Keep in mind, however, that if you have a lot of choices, making the right one can require a finesse roll. So, to create a really believable Duke Ducantus with a spell that can create the illusion of any man, you'll need a finesse roll, because you could have created a lot of different men, many of which are similar to Duke Ducantus but not quite identical in terms of this little detail or that. So, to answer your questions:

Refrain from lowering the magnitude of a spell in case of restrictions! It's a very dangerous route to take. For example, once you start doing that, people will start using spontaneous spells "restricted" to the current circumstances.

If cast two or three times, yes. And they can all look different.

Sure. You can create a person with arbitrary looks and undertaking an arbitrary activity (although making someone very beautiful, or closely resembling someone you know, will take a Finesse roll).

Yes to all; or two people fighting or dancing etc.

The spell provided in the corebook allows you to create any animal of your choosing, up to size+1, i.e. a pony. To create anything larger, you need to boost your magnitude (+1 magnitude for every +3 size, as usual -- so +2 magnitudes for a smallish (size +7) dragon.

Any sound, with two caveats. For a very complex effect, you'll need finesse. And, with T:Ind, you are limited to the amount of sound that a single human can create. So, you can't create the ominous rumble of a charging army without a sufficient boost in magnitude.

Yes. Once again, to replicate closely an existing design, or to make something particularly beautiful, you'll need finesse. But if you just want to appear as a wealthy merchant dressed in "generic" finery or a poor beggar dressed in rags, it's automatic.

So if I understand this correctly, you are saying I only need a single CrIm formulaic spell, Create Sound, and it can create any sound I want?

Ok. I'll need my brain to process this.

My view is that formulaic spells are rather specific, like a recipe; I can't use a chocolate cake recipe to make a lemon loaf, for example, even though the two are definitely cakes and share many ingredients (mmmm chocolate cake).

In my mental model, which I am not sure about and hence the post, the object created and the action performed by the object are fundamental to the formulaic spell. So a spell that creates two people walking could have the two people do any kind of walking. But fighting would be a completely different action and so not covered by the base formulaic spell. If a magus wanted to create a spell that allowed for any kind of movement, I would have expected to add a magnitude to the spell for "any movement".

Specific within limits. For example, if you have Covenants, look at The Phantom Blacksmith. Note that lots of different items could be made using this spell. Yet the spell is reasonably specific in that it turns a bunch of a specific type of metal into a finished, worked product.

Sometimes increases in magnitude for intricacy are included to allow for some more flexibility.

With one spell you can create e.g. any sound that a human being could produce, from walking to shouting to ... whatever.
With another spell you could create e.g. any sound than any animal could produce, from mooing to roaring to stamping to ... whatever.
With another spell you could create e.g. any sound that any fire could produce -- admittedly this is far less stuff than the other two but, hey.
With another spell you could create e.g. any sound that any plant could produce, from rustling leaves to the occasional crack of the wood.
And so on.

The above involves CrIm. If you take existing sounds, you can change them according to the Muto Imaginem examples. A human can certainly be made to sound like anything "at least passably human". Can you make his footsteps sound like the clack-clack of shod hooves of a horse? Probably. Can you make a human's words sound like a hog's grunts? Maybe. It does require a bit of troupe's judgement.

There are indeed modifiers for complexity and intricacy: the book lists them. I wasn't saying that you would get all the effects above at base magnitude.

Since I learn best with examples, here is a proposed spell:

Walking Duo
CrIm 15
R:Voice D: Dia T: Group
This spell creates an image of two people who move according to the caster's wishes.
(Base 1, +2 voice, +2 group, +2 move as commanded)

So with this spell, I could create an image of any two people, who move within voice range, and the movement could be walking, fighting, basically anything that a human could do. I can control the appearance (gender, body, and wardrobe) of the two people. If I want the images to look like specific people I need a finesse roll.

Does that sound right?

Looking in Apprentices (pg 47) I found The Studious Doppleganger spell. That spell is quite specific in what it can do: image of caster on a stool appearing to study a book.

Should that spell simply be "Caster Doppleganger" and when the spell is cast the caster can decide what pose the doppleganger has?

More or less. Three minor issues.
First, and foremost, you forgot adding a magnitude for D: Diam.
Second, Phantasm of the Human Form, which is the closest equivalent, adds one more magnitude for a generic "intricacy". However, that's the same modifier that Phantasm of the Talking Head charges for intelligible speech (which Phantasm of the Human Form can also produce). So if your image is silent, maybe you can omit it. I guess it's a bit up to you.
Third, note that you can really make more than two people. I guess you could create any small group of people, up to a score size 0 adults (that's because a base Individual for a person has Siz +1, i.e. 2 Siz 0 people).

Even though the spell says 2 people, I can actually create a variable number of people (up to 20) using the same spell.

So, in summary:
While the text of this formulaic spell is fairly specific (two people walking), I can, at casting, create any number of people up to 20, each one with their own look, doing any kind of movement. I need a finesse check if I want the images to look like specific people. I have to keep the same human shape, I can't for example use the same spell to create 20 wolves running.

That's gonna take a while to wrap my head around since formulaic spells that are not imaginem seem to be more specific. In the thread I linked, Shape of the Woodland Prowler and Curse of Circe are pointed out as two spells that turn someone into an animal; instead of using the same spell to turn a person into any kind of animal. That's what I expected to apply to formulaic Imaginem spells but that does not appear to be correct.

Forgetting the duration magnitude is what I get for trying to write a spell from work. Since there is no sound, only sight, I did not add the extra magnitude for intricacy.

Yes and no.
You could develop a formulaic spell, with exactly the same magnitude and parameters, that allowed you to create a variable number of people (up to 10 of size +1, up to 20 of size 0, or up to 100 size -2 children). You could also develop a formulaic spell, with exactly the same magnitude and parameters, than only allows only two people -- in fact, that only allows two old bearded men.

So if your spell description says it creates a duo, it creates a duo and that's it -- it's just not been designed to push the limits of what can be achieved with that magnitude. Why would you want something like that? One common possibility is to take advantage of a Magical Focus: if you have a Focus in "illusions of pairs", you could take advantage of your focus when designing your "restricted" spell, which you couldn't do if you squeezed every ounce of flexibility from the design guidelines.

Yes, or anything "difficult". For example, if you want to have them dance in a pleasant way, or mimic the actions of expert blacksmiths if you don't really know much about blacksmithing.

I guess you could push the flexibility in some ways while reducing it in others, but the book does have separate spells for a fire, for an animal, for a human.

Indeed, from the examples we are given, illusions are more flexible than their "real" counterparts. I think that's fair, since from my experience illusionists are somewhat "weak" in terms of capabilities.

So my spell should be:

Moving People
CrIm 20
R:Voice D: Dia T: Group
This spell creates an illusion of up to 10 size +1 people who move according to the caster's wishes.
(Base 1, +2 voice, +1 Dia, +2 group, +2 move as commanded)

In the description, I'd specify that these are images (rather than illusion) that only affect the sense of sight. This is important (if somewhat redundant vs the Base) because it means someone close enough to the images can quickly realize that these are not real people.

It might also need an intricacy magnitude to be added, much like Phantasm of the Human Form. Otherwise their movements or appearance may also be so basic that they don't look real enough.

If not real enough how about completely synchronized? I think the intricacy magnitude is necessary just to create the illusion (SWIDT?) that they are moving under their own power, and not working with perfect synchronicity.