BBB pg. 195 says:

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Indirect Illusion spells are resisted by Intelligence.

Caster successes on most spells are determined by a Sorcery(TN) [+ Spell Pool dice and so on] test.

Note the key word is MORE successes, meaning for Indirect Illusion no net successes are required.

Intelligence vs force.

hah. hadn't noticed that, kanada. thanks. that'll make one of my current runs a lot easier--for me, the GM. heh.

Which means a Force 1 Trid Phantasm with 7 successes will automatically fool anyone with Int-6 or less. The lesson? Get your illusions on the cheap (Force 1 or 2), but back them up with more dice than your target/victim can afford and you'll come out a winner every time.

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Still looking for karma to burn? Get a Force-1 sustaining focus for that Trid Phantasm and you'll never regret it. Cast TP to make you invisible, activate the focus, rest long enough to recover from any drain you might have taken, and Bob's yer uncle. Can also be used to duplicate the effects of Physical Mask, Vehicle Mask, Silence, Hot Potato, etc.

Since Trid Phantasm is so wonderful, as you describe it Spookymonster, I wouldn't describe it that way in my campaign. I would give it a different description, one that doesn't have the powers you describe but still follows what the book says. My description would have the spell less powerful than your description has it, but would still meet what I interpret the spell's description in the book to mean.

For example, I would let it create illusionary sounds but wouldn't have it remove sounds. Therefore it can't be used as Silence. If you want to use Trid Phantasm so that you won't be heard, make an illusion of something so loud (e.g. roaring dragon or diesel locomotive) that no one can hear you over that other noise.

For vision, I wouldn't have it remove things from your field of vision (the job of Invisibility), but I would allow a Trid Phantasm illusion to block someone's view of me. I could create the appearance of a wall 1/2 meter in front of the real wall, and my team could hide behind the fake wall. But no one should sneeze. I could create the illusion of a refrigerator rolling through the door, and carefully walk through the door inside the illusion, but I couldn't make myself invisible to walk through the door.

In my description, the spell's position wouldn't be perfectly synchronized to a moving target. Since the "refrigerator" isn't synchronized to me when I walk, I have to make it large enough that I don't accidentally get an elbow or knee outside the illusion. With a lot of concentration in moving the illusion, I'd have a chance (requires quickness test, perhaps) of walking inside an illusion of a "fat fat person walking", but it wouldn't be comparable to what Physical Mask could do. And neither Physical Mask nor Trid Phantasm would let a Troll appear to be a Dwarf.

My description and your description of Trid Phantasm both do not contradict the description in the book, and both are valid interpretations. But in my campaign, I'd use my description. I do not want Trid Phantasm to be as effective as you describe.

More importantly, most people who are invis still try to be stealthy (subconscious: in case the spell isn't actually working ). There's no rules saying that stealth doesn't work on the Astral Plane, so that mage walking by still needs to spend a simple action (Ie: have a reason to notice you and making a dedicated effort) and roll a higher open-ended test roll in Perception than your Stealth.

So, chances are pretty good that your invis works against 90% of the 1%, assuming you have a couple of dice to roll in stealth.

As for the drain, although I agree that 2D/3D are EASY to resist fully (6 successes with a Trauma Dampener), I don't agree with using them to substitute for silence or hotpotatoe (though mask spells are possible).

Sphynx

I've had a player use trid phantasm to convince a camera over a door that the door remained in place. it was a static scene before hand, so he watched it for a few minutes, commiting it to memory, then cast the spell, including specifically the places where there wasn't anything to see. This was to stop the camera seeing the door open when he went through it. BUT he cast invisibility on himself and maintained it with a sustaining focus first to make sure because he was concentrating so hard on the illusion (which he had no focus for) he didn't want to screw up and have bits of him poking out the illusion which the camera would then see - he was also concentrating specifically on the door area. I raised his target number accordingly because it was such a complex thing to project. I considered this a viable use of the spell with appropriate modifiers applied.

But I wouldn't say it could be used to do physical mask with any convincingness (the character is inside his illusion and so cannot 'see' it properly himself to keep the detail going - hence it being so tough for the character in the above example), or invisibility itself. Or you could allow it, but raise the target number so high that it isn't worth it because people will resist it. Not a problem on cameras, of course, but against living targets it would be very chancy indeed.

My take, anyway.

If only this thread had happened yesterday. I was getting all pissed because illusion spells were so hard to sustain and mask and stayed that way for hours till I realized that only mages had a chance to resist if I throw enough dice, and they can just perceive to beat many of them anyway.

However it is probably usefull to cast indirect illusions at force 3 or 4 anyway (depending on the drain), since your target is 4 no matter what the drain will still be low and you will do better against the odd high int or magical charachter who is using some, but not all thier spell defense on you. It is pretty easy to get four sucesses vs 4 as a starting charachter, but pretty hard to be sure of 6+.

Then you get to the whole crazy problem of spell defence vs indirect illusions. Can the resisting mage use spell defense to resist an illusion spell they do not suspect is an illusion? Seems like they should only be able to use int, or should be required to specify in advance how many of thier spell defense dice they want to use against illusions.

So, just to make sure I've got this clear:

The observer rolls Willpower (for directed mana illusions) or Intelligence (for all other illusions) versus the spell's Force. If they roll more successes than the mage did on the initial casting test, they see through the illusion; otherwise, they're suckered.

Right?

Also, I think that there's no "staging down" the penaties from Confusion/Chaos spells. They either inflict their full effect (+1 on all TNs per caster success) or nothing at all, if the victim gets enough successes. Is this correct?

This is true of all illusions, as stated under the Illusion Spell description. All Illusion spells are either fully resisted or have full-effect.

Sphynx