Gah. I think I've just decided to move invis. and imp. inivs. from indirect illusion spells to manipulation spells and call it a house rule. That's the way my groups have always played them anyway, judging by the discussion above. Any thoughts?

It would only be Improved Invisibility, then. A Manipulation spell that only affects living beings but not cameras doesn't make a lot of sense. The Drain Code probably needs to be recalculated as well.

Major Physical Change (base Serious drain)
Physical Spell (+1 Power)
Sustained Spell (+1 Power)

That's +2(S).

I agree. I've always thought improved invisibility was more of a manipulation spell.

Everything can be seen as a manipulation spell. Regular invisibility would be a control manipulation (similar to influencing someone into believing that you don't exist).

Indeed. The effects of most spells can be obtained through different classes of spells. But it's usually much more efficient (in terms of TN and drain) to accomplish a desired effect by using one class over another.

Holly Hell, What have I started. I thought this would be a quick question but it propted 5 pages of responces in a 12 hour time frame.

So have we decided yet? LOL.

The only reason this has come up is that the mage cast improved invisabiity on himself. The troll wants to shoot the fire sprinkelers to cause a distraction. I just needed to know if this would show the mage or not.

Anyways, thanks for all the thoughts in this thread. I guess it just comes down to a house rule at this point.

It always does.

Assuming any observers failed to resist the spell, at most the sprinkling water might cause any observers to make a Perception check to notice something unusual. The Mage would still be invisible, even if the Perception check succeeds, but if successful, the observers would be aware of something and could target the Mage with a +8 TN.

Done and sold, thanks. I will use that.

And then there was this argument about a dwarf...If an invisable person picks up an item, does the item (or dwarf) become invisable or is it floting in the air?

On that, I would rule that the Dwarf would be visible, but if he were put in a backpack worn by the invisible character, he would disappear.

headed back 'tward the earlier posts....

Yes, ultrasound can put images directly to the eyes, but as can be seen with cameras, II (and, I believe, invisibility) creates a image (after a fasion). Ultrasound picks up sound not images, so it is not fooled whether or not the user paid essence for it.

Invisibility and other sight-based illusions don't affect ultrasound vision. The ultrasound vision rules in M&M say that straight out, and invisibility is provided as the example.

You get a +4 TN for actions directed at someone you can see only via ultrasound, presumably because its resolution is poorer than regular vision.

Sound-based illusions do affect ultrasound vision.

I don't think this supports the "it's all in your head" theory.

Well, except for the whole "affects the mind of viewers" bit, eh?

Note the word "also." Not "this spell is completely different as a Physical spell." It means that it -- pay attention now -- ALSO can affect technological sensors IN ADDITION to affecting the minds of its targets. Amazing!

What it most certainly doesn't say is "this spell alters the subject of the spell so that they become physically invisible." If it did, there wouldn't be any Spell Resistance Test at all because the spell never affects anyone except the subject. Astonishing!

But I think it is fair to say that this spell does not alter the minds of the observers, only the light receptors. If it was minds, cameras would be immune (regardless of the physical/mana category).

And I know what the fluff says, but it's not the first time common sense had to step up to the plate. Eh?

No it alters the minds. It says "the mind of the viewer". It's an illuision.

It's the camera I'm having trouble with. Help me out here. Mind of the camera? What mind? How?

It also affects cameras. The spell reaches out and erases the data from the film or whatever else it needs to do to erase the image in addition to its regular ability. How does it work exactly? Who the frell knows? It's magic.

The only camera that it cannot touch is the one with the astral film.

Then why doesn't it work on ultrasound vision?

Or even an ultrasound camera type thing?

Because, despite the pseudo-visual feedback it gives, it's inherently a sound-based sense. Invisibility only affects sight.

And therefore it is easier to rationalize the effects of invisibility by saying it effects the photo-receptors (eyes and lens) instead of merely considering the mind. If it was truly a mind effect, the image produced by ultrasound would be altered since it is perceived by the mind and and by videotape as a visual image regardless of the sensing medium.

Whatever. Explain it however you need to in your game. Be default, it's a magical spell that creates an illusion in your mind of the scene you're seeing, but altered so that the subject isn't there.

In regards to the ultrasound vision thing, heres my take.

Imagine that you have combination of an ultrasound emitter, an ultrasound detector, and processor that converts the data recieved by the detector into an image file, all of which exists as an independent, external device. The improved invisibility spell does not fool this device, since it is not using visual detection, and so it succeeds in recording the sonic patterns and transcoding them into the image. Imagine, further, that rather than saving the image as a file, you have a radio transmitter attached to the external ultrasound processor, and it beamed the transcoded information back to a display screen a half-mile away in real time. You would be able to see the image it produced, because it was an image compiled from data that was not affected by the invisibility spell.

Now, imagine that this whole contraption AND the display screen are small enough to fit inside your eye, and that, since it's in your eye, you can replace the radio transmitter with a tiny fiberoptic cable linking the processor to the display screen. Oh yeah, thats what the Ultrasonic vision eye modification is!

If you agree that you would be able to see the image produced by the external device on that display screen (and you most definitely should), then you shouldnt have any problems with the idea of being able to see the exact same image produced in the exact same way by the cybernetic version. The processor in this case is the part that would be affected by the spell, but since the processor is recieving sonic information, it is not fooled.

Just to murk up the waters some more, there's also that section in the Illusion category description that specifically mentions that they can 'manipulate energy', despite the fact that they don't fall under the catch-all Manipulation category.

[edit]
BBB, p. 195:
"Indirect illusion spells manipulate energy to create an illusionary image or sound or other sense-based effect, fooling the senses."

See Da9iel, we can still have endless wars over Improved Invisibility. Agreeing on how to handle the rules doesn't stop the conflict, just changes it to same one that's been battled dozens of times in the past until one side gets bored or forgets their password.