This all started with one of those things I've just never even thought about- I read, I think for the very first time, the line on pg 113 that reads:
Disbelief: The character may instead make a Sense Motive (Wis) check to save against the effect.
While I think this definitely has a cool flavor, it means that certain types of characters (player and not) are almost outright immune to Illusion spells (at the current moment there is one illusion spell- Confounding Images- that could target someone unwilling and isn't disbelief) and granted that mostly includes just the Illusory Image spells, but they're pretty iconic and I suppose they're pretty broad (which might be why it exists- just as a balancing factor).
More than anything it caught me off-guard and I'd wager I'm not the only one who's missed it, but when I was considering the in-game use of such a rule (and whether or not I was going to keep it, really) I realized there isn't any mention of what exactly makes an illusion's save go off (actually, rules for saves assume you can use common sense to figure out when you have to make a save, which is completely appropriate because I didn't even realize the rules were missing until I looked for them just now).
So while there may or may not be an official position on how Illusionary Images trigger saves I was
wondering, how do you guys run Illusions? Does the save trigger upon interacting with them (like in D&D), upon seeing them (which would likely make sense with Sense Motive), or something else? Come to think of it, there's mention that Illusions lack texture- can they be touched at all and if not do you grant bonuses to saves for that (or even make the save automatically succeed)?
I'm not trying to poke holes in the concept but it was something I had almost glossed over with assumption, just figuring I'd be running it like I always have, but now I'm interested, like I said not just in any official opinion but also in how other GMs run it (or would run it).
Edit: D: Emissaries care not for your foolish Illusions!
Edit again: What I'm thinking I might run with myself (as far as the Sense Motive thing) would be to use Sense Motive opposing the Spellcasting result to make it more like a forgery, trying to see through the caster's craftsmanship of the illusion, hmm.