can light pass thru illusionary wall?

[rom90125]

Setup: Assume illusionary wall is cast in a dark cavern to conceal the entrance to a side tunnel. At a later time, a PC wanders thru the cavern using a torch as her lightsource.

Q: Can creatures in the hidden tunnel, on the opposite side of the illusionary wall, see the light coming from the torch in the cavern? If so, is the light filtered in anyway as it passes thru the illusion?

Thanks.

 

[Patryn of Elvenshae]

It passes through, as light is basically an emanation. Emanations work until they have a blocked line of effect.

Illusionary walls do not block line of effect.

EDIT: Note that this assumes that the people hiding know the wall is illusory, and therefore can see through it.

If they are not aware that it is illusory (i.e., have not made their saves), then the light is probably not visible until the light source is rather close to the wall, at which point the wall itself will appear to glow.

 

[DarkMaster]

No, otherwise it wouldn't be an illusion.

An illusion is usually affecting your sight. If light was going through then there wouldn't be an illusion. Images are created by the light reflecting on object, captured by your eyes an processed by your brain.

 

[rom90125]

Patryn,

Thanks for the 411. Another question, based on your response. If the PC happens to be walking next to the illusionary wall, without knowing the wall is not real, will she 'see' light reflecting off the illusionary surface? Assuming the PC is that close to the illusion, without actively looking for it, would you grant a +1 or +2 circumstance bonus to the character's Spot check? I suspect even though the PC doesn't know the wall is an illusion, she would get some type of positive modifier to her Spot check to represent her proximity to the spell. And if she were to make her spot check, she would 'see' what appears to be a shadowy image of a tunnel on the surface of the wall. At this time she would roll her Will ST.

Can I get your thoughts on the aforementioned scenario?

 

[Mahali]

Patryn,

If the PC happens to be walking next to the illusionary wall, without knowing the wall is not real, will she 'see' light reflecting off the illusionary surface? Assuming the PC is that close to the illusion, without actively looking for it, would you grant a +1 or +2 circumstance bonus to the character's Spot check? I suspect even though the PC doesn't know the wall is an illusion, she would get some type of positive modifier to her Spot check to represent her proximity to the spell. And if she were to make her spot check, she would 'see' what appears to be a shadowy image of a tunnel on the surface of the wall. At this time she would roll her Will ST.

Can I get your thoughts on the aforementioned scenario?

Yes, just like you'd see your reflection in an illusionary mirror.
No bonuses to spot rolls. If there was it'd be in the skill: spot or spell description.

You get a will save when you interact with the illusion. Looking at it isn't interaction.

 

[rom90125]

Yes, just like you'd see your reflection in an illusionary mirror.
No bonuses to spot rolls. If there was it'd be in the skill: spot or spell description.

You get a will save when you interact with the illusion. Looking at it isn't interaction.

Fair enough. Thanks for clarifying this issue for me.

 

[cmanos]

I don't know the answer to this, but I'll ramble.

If light is allowed to pass through an illusionary wall and there is a creature standing on the other side of it, the light reflected from the creature would also pass through the wall. So the creature would be visible as an image as part of the wall...perhaps a painting on the wall, or an insubstantial creature.

 

[Patryn of Elvenshae]

Remember that you don't get saving throws vs. illusions until you "interact" with them - whatever *that* means.

Therefore, the person walking by with the torch (along with any others near them) might get a Spot check with a decently high DC (say, the save DC of the Wall?) to notice that it isn't reflecting light quite the same way as the stone around it, but that's a DM call.

More likely, until they actually interact with the wall, the PCs' minds will fill in the missing data, and the wall will look just the wall next to it - and the PC certainly won't see the tunnel behind the wall until they either step through the illusory wall or successfully disbelieve it, at which point it largely fades from view.

 

[Christian]

In 3.5, illusion(figment) spells can't generate light; therefore, they must reflect light, otherwise they would be invisible ...

 

[ThirdWizard]

Something just popped into my head.

Adam is on one side of the wall, and Bob on the other. Adam has a very bright light, and Bob has Darkvision. Walking up to the wall, Bob sees no light but then touches the wall and makes his will save. Suddenly the area Bob is in is highly illuminated! But, wait! Chas is with Bob, and Chas did not make a Will save. He's still in the dark!

Oh what tangled webs...