The core book says that astral perception is done by assensing, which is a sort of psychic sense. Tradtitionally in Shadowrun, this has meant that illusion spells like invisibility did not affect astral perception. They might decieve your vision, but since you don't use your vision on the astral, it doesn't matter.

But all the book says about spells on the astral plane is that only mana spells work on the astral. What does this mean for mana based illusion spells? Do they still work? Sure, invisibility affects your vision, but it's not like it targets your eyes, or even the vision center of your brain. It targets your "mind," erasing the mage's visual presence from it. Or does it? If it did, then you wouldn't be able to "see" the mage with ultrasound... right?

I would say "I sure hope the magic rulebook clears this up," but it's already been published and it's no help

Even although invisibility makes the target vanish from the physical sight of anybody else, a person with astral perception will still see the guy because of the aura of the spell, and the aura of the person.

In the end, don't think too hard about the invisibility spell (mana- and physical version).

But what about Agony? Does that still work? An astral form can still feel pain, right? Or is that not the case?

And if that wasn't enough to cook your noodle, how about "Bugs?" Bugs is a spell that includes visual, aural, taste, smell, AND touch illusions. If invisibility doesn't work on the astral, then you'd expect that the visual part of 'bugs' doesn't work either. Same with stealth -- you don't hear on the astral, so something that makes fake sounds won't affect an astral form. But if agony works, then the touch illusion of Bugs would work too...

I believe illusion spells work, but are obviously illusion spells, so invisibility won't work, entertainment will.

However, a manipulation spell that made you ignore the target (an SEP field) would still work.

The main thing is the description of the relevant illusion spell. Invisibility is a single-sense spell-in this case, sight. It can work perfectly and you're still detectable by your squeaky shoes, the fact that you haven't bathed in a week, bumping into people, or your aura (to astral perception). This is clearly delineated in the spell.

That said, it's explicitly given that you can cast mana-based illusions on the Astral:

Given that it is very easy to "see through" an illusion on the astral, realistic illusions-say, the illusion of a mana barrier or astral construct-would only really fool an apprentice; it might fool the really gullible mundane that wanders into an astral shallow, however. Obvious illusions can get some more play, either for entertainment or, say, to clearly illustrate a building layout to an astrally projecting comrade. Offensive spells like Confusion and Agony work perfectly fine against astral targets-realizing that it's an illusion doesn't help when you feel like you're in an astral blender.

The unfortunate consequence of this is that using magic to deceive people who can astrally perceive is mostly an exercise in futility.

Good catch on p.201! They like to keep us guessing about where a particular rule or clarification will be found...

So this means that if you fail to resist an invis spell, you just need to make an assensing test to see through the invisibility illusion? It talks about recognizing things as illusions, but just because you know invis is an illusion doesn't mean that the person becomes visible. It seems like, despite the fact that you'd know someone was there, you wouldn't have line of sight on their aura to target them with a spell. But you could probably attack them in astral combat, since even though you can't see them the aura of their invis spell tells you where they are.

Invis only works on sight, not astral perception, so glancing astral gives you LoS to the invised intruder. If you aren't naturally dual natured, there may be a penalty for trying to shoot a person with only having their aura to sight with, but that may only be in SR3 and is open to debate (or brutal GM ruling) on what counts as a purely mundane task.

Barring careful planning and special circumstances, it can be. A good way to go about it is to scout out the local astral plane and situate your illusion to take advantage of the Astral Visibility Modifiers (p.114), or else create your own (Mana Static spell, I choose you).

A particularly potent magician, or a team of less-accomplished spellslingers, or even an average magician with some prior planning and anchoring foci, can really get an advantage by combining spells for greater effect. Spells like Bugs, Confusion, and Orgasm are disabling enough on its own, but also can make Assensing Tests more difficult-combine it with a Double Image of yourself and there's a 50% chance your astral enemy won't hit you with a spell even if he gets it off. Assensing Tests are based on Intuition, so a Decrease Intuition spell will signficantly impair their ability to pierce the Mask spell disguising your aura (good for getting past dumb watcher spirits).

AH, that's awesome ....

I second the motion. I am so stealing that idea.

=i)