Illusion Clarifications

[zuljita]

We had an intense discussion tonight about Illusion spells and I'd like some clarification. In a scenario where Fiona the knight is standing in the gap between Sapphire the wizard and a horde of ravening Demons from Beyond the Stars:

1) Perfect Illusion: if a perfect illusion is cast over Fiona to look like a wall, can Fiona see out? If yes, and Fiona stabs the demons, what limitations do they suffer when they retaliate?

2) Can Sapphire cast a "one way" wall perfect illusion so that Sumha the Barbarian and Colarmel the Knight-Priest can use their halberds to attack things on the far side of the wall? (Sapphire's player suggests things like a bright light, or a one way mirror.

3) Can Sapphire anchor said perfect illusory wall on Fiona using Illusion Disguise despite the fact that the wall isn't humanoid in size or shape? Does modifying the illusion to become a disguise give Fiona the ability to see through it if she couldn't in 1)?

4) Could a tapestry illusion be made that shows in real time what's on the other side of the illusion using Independence or initiative.

[mlangsdorf]

My assumption on illusions is that they are effectively 3-D, insubstantial, matte paintings. It makes them fairly powerful but gives them fairly intuitive limits: anything that George Lucas couldn't do with a matte painting, an illusion can't do either (unless the spell says otherwise!)

Originally Posted by zuljita

1) Perfect Illusion: if a perfect illusion is cast over Fiona to look like a wall, can Fiona see out?

No. She's inside the illusion, and can't see through it or been seen while she's in it.

Originally Posted by zuljita

2) Can Sapphire cast a "one way" wall perfect illusion so that Sumha the Barbarian and Colarmel the Knight-Priest can use their halberds to attack things on the far side of the wall? (Sapphire's player suggests things like a bright light, or a one way mirror.

Illusions aren't Light & Darkness (which cover Invisibility) or Knowledge (spells like Earth Vision). An illusion can obviously have different images on different sides, but that kind of pass through effect would require the illusionist to essentially be painting the image of what's happening on the far side of the illusion. So if the wizard can see what's on the other side of the illusion, he can project that on the near side of the illusion. Doing so is going to distort the perspective quite a bit, so I'd treat everyone using the illusion for targeting things on the other side as though they had One-Eye.

Also, stabbing a sword through a Perfect Illusion damages it, so the DfBtS will realize it's an illusion (Spells p 41).

Originally Posted by zuljita

3) Can Sapphire anchor said perfect illusory wall on Fiona using Illusion Disguise despite the fact that the wall isn't humanoid in size or shape? Does modifying the illusion to become a disguise give Fiona the ability to see through it if she couldn't in 1)?

Yes, and yes. I would probably give people a bonus to notice that the wall is an illusion, but this seems valid to me.

Originally Posted by zuljita

4) Could a tapestry illusion be made that shows in real time what's on the other side of the illusion using Independence or initiative.

Initiative with a minimum IQ of 4+ seems like it would have senses, so it could "see" out of one direction and alter itself to show what it sees with the other. It's essentially making Sense rolls all the time, so a higher IQ is going to result in a clearer image: if you want to be sure that the monsters on the other side of the illusion are exploding Doomchildren and not weapon destroying Rustchildren, then your wizard may want to up the IQ of the illusion to 12+,

[Dalin]

Originally Posted by mlangsdorf

Illusions aren't Light & Darkness (which cover Invisibility) or Knowledge (spells like Earth Vision). An illusion can obviously have different images on different sides, but that kind of pass through effect would require the illusionist to essentially be painting the image of what's happening on the far side of the illusion.

I like this way of thinking about it. I assume holes in the illusion would be permitted? With favorable lighting conditions, an illusionist could add one or more peepholes to a wall which would do the trick. Or create a stone trellis or grill with small holes. This would make the dark side nearly invisible, but the brighter side would be easy to perceive.

I haven't run a game with a PC illusionist in many years. I recall it raising lots of thorny questions.

[mlangsdorf]

You can create an illusion of a castle wall with arrow slits, so a wall with peepholes would work, too. And illusions can have gaps in their area, so the peepholes would be actual gaps in the illusion, not projected images of the other side of the illusion.

I think I would go with arrow slits myself: people expect to be attacked from arrow slits, and don't start looking sketchy at the wall when an arrow or spear comes out of arrow slit. Missed attacks from either side might damage the illusionary wall, which dispels simple illusions and disrupts perfect illusions, but a wall with arrow slits is a good way to provide cover for the friendly side.