Topic: Do invisible characters still cast have a shadow?

[mtpnj]

A discussion came up the other night as to if an invisible chracter would cast a shadow.  Spell law does not seem to give an answer on that.

[rdanhenry]

No.

[GrumpyOldFart]

I don't know what the rules say, but I would say no. So far as I understand it, Invisibility is a twist on a visual illusion, whose whole purpose is to reproduce the patterns of light on any given side of you that an observer would see from the other side if you had an absorptive/reflective/refractive index of zero.

So... how much of a shadow would be cast by something that doesn't change the path of light at all? That's how much of a shadow you should cast, if the spell is working properly.

Keep in mind that RM makes the distinction that essence illusions have nothing to do with what the observer believes, a visual illusion's effectiveness is based solely on how well the caster can tweak the properties of light within the spell's area of effect.

[markc]

There are a few topics like this in the archives that you may want to check out.


 In RM invisibility has a fringe effect during rain and IMHO in this case you would see some type of shadow. But normally no you would not see a shadow.
MDC

[Marc R]

The shadow of the fringe effect would be faint and shimmery, like when you have a radiator under a window, and you can see the heat shimmer in the box of light projected on the floor. . .it most certainly wouldn't be anything like a full out shadow, Of all the secondary effects of an invisible person, the one most likely to give them away is the foot prints on anything but a hard clear surface.

[arakish]

Does an invisible char cast a shadow?

Depends on the GM.  I have always ruled that they do cast shadows, but they are fringy, hazy, dull shadows.  And that only occurred in full sunlight.  In lesser light, I ruled that the shadow was not as visible.

My way is full sunlight = a shadow 35% transparency of shadow if were visible.  Less light = less shadow.

Furthermore, if the invisible person did not move, then it became very difficult even to spot the shadow.

rmfr

[Zat]

Does a pane of glass cast a shadow?
I suppose it does, but it's very subtle. Hence the fact that there is a penalty of -90 to perception in detecting invisiable creatures/people/items. Of course, one could rule that there is no shadow and other, subtle means of detection are present, e.g., The 'Predator effect' (see the Movies), foot prints, sounds etc. Whichever you choose, the result is the same; a -90 to detect the invisible creature unless of course you are clever and use some other, outside influence.

[GrumpyOldFart]

Does a pane of glass cast a shadow?

Yes it does. But how often does anyone see the shadow of a pane of glass with unchanged sunlight around it, rather than the deeper shadow of something opaque, like the wall the pane of glass is set in?

[Cory Magel]

Somewhat 'realistic' answer: I don't recall where I've read this over the years, but I believe there is a description that states the Invisibility spell is bending the light around the person/object, so it is not actually passing through them (i.e. no window shadow effect).  Simpler answer: It's magic, so no.  Simplest answer: Your the GM, do what you want.

Also keep in mind the Fringe effect occurs if something moves into an invisibility radius after the spell is cast.  In the case of rain, snow, etc you would see the entire effected area shimmer somewhat as a result (if it is the usual invisibility it would be in the shape of the individual most likely).  But this also applies to if you cast an invisibility sphere and then someone else tries to get inside of it as that person would have the shimmering outline then (or any other object that entered the radius).

[mtpnj]

Thanks all.  I was kinda thinking along the same lines as Arakish.  Now of course my players are thinking I am a big meany. (Their words are not as kind of course.) So everyone that did not agree with me and Ara sold me out.  LOL. Just kidding but I think I recall reading about the light bending thing along time ago also.  Been playing this game so long through so many incarnations hard to remember where.

Thanks for all the good comments.

[TAK]

Simpler answer: It's magic, so no.  Simplest answer: Your the GM, do what you want.

This would also be my answer.

[providence13]

I'm thinking that there should be a shadow, even if it's so faint that most don't notice.
A straw in water appears to bend or break because of refraction. We know that it's an illusion, but the physics are working perfectly so all we can do is compensate. Same with spear/bow fishing from a boat. You can't disbelieve the illusion to ignore the effect.

Open a can of gas/petrol on a hot day and the fumes cast a shadow, even if we can't see the vapor. We know gas is there, we can smell it (and hopefully the can is red), but looking directly at the nozzle, the vapor is invisible.

Refractive index is how light propagates through a medium. If air is 1 and water is 1.33 there will be some fringe effect when looking at the straw. The gasoline vapor has a shadow because it's refractive index is 1.0017. Just enough to be different if you're really paying attention.

Invisibility spells do have a fringe effect in RM. IMHO, this means that normal light and the invisibility field have different refractive indexes. Larger and faster fields have more noticeable fringe effects.
If the refractive index is different than air, then it's a different medium and might cast a shadow.
So even if the character doesn't, the field might..

[TAK]

Speaking of physics is all well and good, but this is magic, it doesn't play by the rules.

[jdale]

Speaking of physics is all well and good, but this is magic, it doesn't play by the rules.

And in fact it can't to get the results described. E.g. it doesn't matter whether light goes around or passes through without stopping, in either case a simple physics explanation would result in the invisible person also being blind. Which is not an effect of the spell.

Too much physics is a danger for magic. Don't worry about that nonsense. Sometimes actively denying physics will help you explain the world better. For example in my main game, the stars are not physical objects but landmarks in the dream realm which happen to be visible because of its proximity. This explains why you can use them for predicting the future, because movements in the dream realm reflect large scale trends in what people are dreaming about, which in term reflect things that are happening, planned, feared, or expected.

[larien]

If you're playing in Middle Earth or equivalent, an invisible character would cast a shadow; at least, Bilbo did when wearing the ring...

[providence13]

Speaking of physics is all well and good, but this is magic, it doesn't play by the rules.

I hear ya! For me, speaking of physics doesn't change the rules. I didn't propose any rule changes. I'm just trying to wrap my head around the how's and why's. The "magic" could also use a prism effect to enable vision by gathering so many scattered points that it rebuilds what you would normally see. Nothing changes, it's just how I choose to look at it.


IMHO, this also touches on RM illusions. Even if you know it's an illusion doesn't matter. It's still there.

Also, I appreciate the reminder about Bilbo and his shadow. He was also pretty sneaky to boot.

[Arioch]

A discussion came up the other night as to if an invisible chracter would cast a shadow.  Spell law does not seem to give an answer on that.

It does if it's cool for your group to think so.
Invisibility still gives all the advantages listed in spell law (cannot be seen, awareness maneuver needed to detect the invisible person/object,...), but the description of its effects in the fiction you create at the table can be whatever pleases you.

[rdanhenry]

If you're playing in Middle Earth or equivalent, an invisible character would cast a shadow; at least, Bilbo did when wearing the ring...

He could also attack or bump into things all he wanted without becoming visible. Obviously not the same type of invisibility at all.

[providence13]

As often, you are right rdanhenry.

But Invisibility from an artifact, (the most powerful artifact..?) which does seem to have at least empathy Intelligence, could have different rules.
Maybe something more powerful than 50th lvl True Invisibility.. I don't know MERP.

[Cory Magel]

True, the "One Ring" probably sits pretty high up on the magic item power level.