Perhaps I'm not reading the book carefully enough, but I'm not clear on why Perdo Imaginem does not remove the target's shadow.
There seem to be three options:
The target and the target's shadow are two different things. A separate Perdo Imaginem effect would be able to remove the target's shadow.
A shadow is cast by the sun (or the moon). Or, more properly, the species of the sun are blocked by the target of the spell, casting a shadow. Effecting the species of the sun is outside the boundaries of Hermetic Magic, because of the Limit of the Lunar sphere. So an invisible target would not cast a shadow indoors under a standard invisibility effect.
There is another thing I'm not thinking of.
Any thoughts? (Clearly I have an Imaginem specialist in my story )
It does not remove the shadow because the designers of the spell thought that this would look cool.
So it is option 3.
There is nothing in the rules that justify it. Feel free to determine that the shadow disappears as well. But it is a low level spell, so you might want to make it "less than perfect", with small drawbacks like this one. Invisibility is one of those areas where debate is never settled. There is even a whole section in HoH: societates that deals with invisibility and tries to nerf it artificially for combat purposes (IMO) because it is too powerful according to the guidelines.
Personal take has been to redo the Imaginem baselines, the stated levels not "destroying" the ability to affect one or more senses, but reducing it roughly 50%, +1 magnitude to improve it up to 80-95% which means a sight affecting spell would make you very nearly invisible, what i like to call "preddy-invisibility"(Predator movies and games) and finally with +2 its a total effect.
Shadows remaining unless +1 magnitude to severely reduce it or +2 magnitudes to remove it completely.
This places a "perfect invisibility" spell up at level 40, which balances quite alright i think, while still allowing semi-invisibility as low as level 20, something that is still superbly useful if for example its nighttime or otherwise very dark.
AND more importantly it allows SOMETHING in between the total extremes of visible and invisible.
I'll simply suggest that there are other readings of the rules on this subject. 8)
#1 is the closest. But it is true that there are multiple interpretations, and (most) all are supported by (some part of) the RAW.
It's the same reasoning that allows PeIm to remove "touch" from a person's fist, but the person punched in the nose still hurts and bleeds and lands on their butt. Never felt the fist itself, but they feel the effect. (And, yes, that's a bit of a brain-twist, but it's magic, it doesn't have to "make sense" to the average person. If it was easy, ~everone~ could do it!)
It's possible (depending on your interpretation) that a PeIm spell affecting "group" would cover it, as they are two different "species" that you are trying to obscure. Or it might require a MuIm spell, since you are not "removing" the entirety of what is seen in the shadow, but merely "brightening it up". That might require an Ignem requisite, if you approach it as an associated issue of "light/shadow" and not purely "species".
(Can't be #2, or various PeIg "Shadow/Darkness" spells would not be possible.)
(And game balance is not removed from the final equation. An invisible sociopath with a dagger is powerful, but any "fun" is a matter of differing opinion, especially in the long term. But that's why each Troupe can interpret such things differently, to suit.)
Nothing in the rules, but plenty in the setting. PeIm removes an object's capacity to produce species. It does not remove the object's ability to inhibit rays of light, or produce a reflection, neither of which have anything to do with species produced by the object.
So it is not a result of "looking cool", it is a feature of the game's paradigm. (Yes, I did use the P-word!)
Regarding shadows in general, I would say that it is very hard to affect them with Hermetic magic. A shadow is not a thing, it the absence of a thing (light). Without light, there are no species (which travel through the medium of light). A shadow is therefore a natural lack of species.
You can create more shadows by destroying more light, or remove them by creating more light from a different direction, but you can't make them look like something else, or move them; any more than you could move the image of an invisible person.
Your saga may differ - you've probably got the idea by now that I have a "hard" view of medieval physics in my saga. This is perhaps to be expected, considering whose name is after Matt Ryan's on the cover of Art & Academe!
So, something that is not there to be seen (produces no visual species) produces non-species (POSITIVE non species) in the form of shadows?
The truth is that this spell has produced a shadow since 3rd editionat least (bnooks at home, but it has since 3rd at least) and the ammount of pedantic paradigm physics were quite low at the time. So, I keep my opinion that the "shadow does not disappear" is because of it looking cool, not because the spell demands it at all.
There is no "production of non-species". A shadow on the ground is a failure of that patch of ground to produce species, because there is no light to excite or transmit those species. The reason that there is no light is because of the object in the way. The fact that that object is itself not radiating species is not relevant. It's wierd, but it's consistent.
A window (let's assume an anachronistic perfect, flawless pane of glass for the moment) does not produce a shadow. However, it is different - it is transparent to light. Perdo Imaginem does not directly impart the property of being transparant - that would be a Muto Corpus spell. The fact that people can see through an invisible person is because they don't radiate any species when light hits them. So the species of whatever is behind the person strikes the eye of the viewer. For most purposes, invisibility and transparency are the same, but not when talking shadows or reflections.
This was a relatively new field of study in the C13, but superior to whatever beliefs came before. For example, if a shadow was a thing - and thus species of darkness existed - then you would not be able to see through a shadowed area because those species would get in the way. If you looked through an open-ended tube, you would only see darkness. Because light can travel through shadow without provoking species, shadows themselves must be the absence of species.
To get back to the issue: Perdo Imaginem destroys your image. In the 5th edition this has been interpreted as destroying the species that comprise that image; which is a clever interpretation of how the magic works. It also has some nice touches, such as the persistence of shadows and reflections.
I beg to disagree:
There is nothing in the rest of the section about shadows, nor under the general description of Imaginem. I can't comment regarding 2nd or 3rd editions, but a general observation is that things are added with each edition, not taken away.
I agree/concede that the persistence of the reflection exists in previous editions, probably for the coolness factor. However, I believe that the persistence of shadows was probably specifically added in this edition to conform with the game's paradigm as to how Imaginem works.
Strange as it may sound, you could also use ReIg to produce true invisibility by bending light around the target. No shadow there either. It sounds anachronistic and modern, but IMO is perfectly consistent with Euclid's Optics, and the whole idea of species. Essentially, light is the medium through which (visual) species travel, so controlling light should manipulate the species.
Once I had a character concept for a wacky Flambeau researcher who was trying to come up with all kinds of weird applications for Ignem; needless to say, this was one of them. Never played him though.
Agreed. More efficient, but also possibly more difficult. There isn't currently a suitable guideline for changes like this under MuCo. I would probably rate it as equivalent to changing into an insubstantial object - you are not still recognisably human, but neither are you a solid inanimate object.
I might be persuaded by my players that the various guidelines for adding a Soak bonus are specific cases of (unstated) general guidelines of adding unnatural features. Thus the lvl 25 base is actually "give a body a wholly unnatural feature, such as a +5 Soak or perfect transparency", or somesuch.
Several books on Optics are due to be published later in this century (but post-1220). Following these, and some original research, the specific case of transparency might become easier still in my saga.
I believe there is, altho' there is nothing specifically in the rules about how shadows and PeIm interact. However, there is nothing specifically about many such things*, and no one has a problem extrapolating for those.
(* such InIg spells interacting with magical "light" rather than magical fire, etc. etc.)
Without presenting a formal syllogism*, the PeIm Guidelines state that they destroy images, nothing more. Removing the image of the object does not address the image of the shadow, which may extend quite a significant distance away. (Think of a figure on a castle wall, with it's shadow falling on the ground far below.)
Further, by most of the given definitions of "Individuals", whether generally or specifically under Imagonem ("an adult human being"), an object and its shadow are not by default a single target. At best, "Group" would be required - and only if you believe they can both be approached identically.
I don't think you need to resort to something as tenuous as "the setting" to support this interpretation effectively, tho' the synergy of the two combined is stronger still.
(* I could, but that would be dull, and we all know almost anything drawn from the rules is far from iron clad. Interpretations abound, and I won't just so someone can poke the predictable holes in it. My point is simply that there are elements in the rules that point to it, if possibly also in other directions.)
Interesting ideas. I was digging into the invisibility rules in Societates just last night. I am revising old items in preperation for posting, and I was wrestling with this myself. In the past, I always figured that the base level for invisibility contains some fatal flaw. Wasn't looking at the physics angle, just a game balance angel. Anyways, I always allowed for one magnitude higher to be Improved Invisibility, eliminating the shadow/reflection. But even if you have silent improved invisibility with no scent, I would still go by the chart on page 33 of Societates. The different improvements should be taken into account only when determining rank of detectability.
This thread has been here for nine and a half years and I don't recall seeing it before.
My take is that shadows are an ignem thing and the best way to get rid of them is with a creo ignem spell to fill in the dimness with just the right amount of light.
You could probably creo imaginem a better lit section of stuff over the top of the shadowed area, you might muto imaginem the shadow area so it looks a bit brighter and matches its surroundigs, you could even perdo ignem the area surrounding he shadow to be a little dimmer and match.
But you couldn't perdo imaginem the shadow because it isn't an image.
I rather like the idea of shadows being themselves particular species that are replaced by other species, after all "nothingness" is an "unphysical" concept (at least in my view of the world). This enables such a thing as actually casting spells on shadows as their own thing, or stepping into or out of shadows, travelling through shadows ( I love that trope). So maybe the answer is that there needs to be a new Form of Shadows/Void, which allows the elimination of shadow species with PeShadow.