(3.5) Spell with a silly name I have had in my head a while

[DracoDei]

This is partially based off a movie (Beatles movie?) where there were glasses that would let you see invisible alarm lasers... but nothing else. Not even the floor.
With a less silly name(EDIT: False Seeing could work for somewhat less silly, don't know if that would fly for a really serious game... maybe something like Bagor's Vision?) this could work even in a serious campaign.

Q-Ray Vision
Transmutation
Level: Sor/Wiz 3, Brd 3
Components: V, S, M, F
Casting Time: 1 standard action
Range: Touch
Target: 1 creature
Duration: Up to 1/round per level (decided at time of casting)
Saving Throw: Will Negates (Semi-Harmless)
Spell Resistance: Yes
The target becomes blind and deaf to all real things and all Patterns. This includes even via Blindsight and other such abilities as well as via any type of divination spell or effect. They are considered to fail their saving throws to disbelieve against all non-pattern illusion effects*. However they also retain enough clarity of thought to recognize that since all real things are undetectable to them that anything they are seeing must be an illusion even as they are subject to its full effects. They may communicate this information if they wish.
Note that this does not reveal creatures with multiple forms(since that is a transmutation effect, rather than an illusion effect), they are undetectable to the target.
*Any saving throw allowed against the real counterparts of a Shadow Evocation or similar spells they are subject to, or the special abilities of any Shadow Conjuration, Shades, or similar quasi-real creatures are rolled normally. The same applies for the fortitude save to not die when effected by Phantasmal Killer and similar saving throws.
Material component: A shot-glass worth of of distilled liquor with a copper-piece in it. The Liquor must be drunk by the caster, but the copper piece may remain behind (although swallowing it accidentally doesn't NECESSARILY ruin the spell, especially if you happen to have Silenced it).
Focus: Said copper-piece.

[PairO'Dice Lost]

Well, this is certainly a...unique way to detect illusions. Less annoying than true seeing, more fun for everyone at the table. No mechanical issues I can see; I like it.

[DracoDei]

Have added a bunch more boiler-plate. I hope that was a wise decision. Most substantive change is that the target now no longer auto-dies to Phantasmal Killer and it is clear that it reveals (or, technically, fails to obscure, Magic Aura).

[Owrtho]

Just a thought, but seeing as how they become blind, I'd expect some kind of penalty to balance checks, maybe climb checks, and reflex saves (at least with non illusions).

Owrtho

[Tar Palantir]

That's included in the penalties for being blind. (http://www.d20srd.org/srd/conditionSummary.htm#blinded)

[Worira]

I like this. You could probably drop the spell level to 2nd, especially if you change the range to personal to prevent using it as a blinding touch attack. Even with that, though, it requires a touch attack and allows a save and SR, so it would probably still be fine at 2nd.

[Debihuman]

Shouldn't the duration be 1 round/level (D)?

Debby

[DracoDei]

Worira:
I liked the idea of it being able to be used offensively as well, and also you might want to put the buff on a team-mate instead of yourself. Besides, True Seeing is touch range so it seems appropriate. I originally was going to do it at Personal and Level 2, but this seems moire fun. Although I might drop it down to 2nd and leave the range as touch if people agree that would work.

Debihuman:
Nope... definitely not dismissible.. that would take half the fun out of it! You have to decide how long you want it to last before you cast it.