adzling, do you have a rule reference for #1? Specifically the "you don't see it" part.
I play it that you see the illusion but that you know it's an illusion. Call it a semi-transparent effect, so you see that the caster is supposed to look like Granny but you can tell that it's actually the Big Bad Wolf.
But, reviewing the rules, I don't see any text that supports either interpretation explicitly.
I too have ruled in the past that Illusions that are resisted are obviously fake, though still visible. Otherwise there is a whole class of spells that could potentially be useless and another that gets odd results if some people resist and others don't.
The Entertainment Spells are always obviously illusions, its creating a light-show for purely entertainment purposes. I'm actually not even sure what the point of resisting these spells is, but there isn't really the option to choose to fail. If people resisting these spells just flat-out didn't see it, it would be bad, and could potentially be even worse.
The Phantasm spells, and really any of the spells that creates a physical effect (Physical rather than Mana-based Illusions) create an actual visual effect. It isn't something only visible in the mind's eye, that's why Cameras and other technological items can see them. If resisting these spells made them completely unseen, you have a case of reverse invisibility. The person who succeeds at resisting the spell doesn't see "person standing right there" while everyone else does. From a meta-game perspective, we know what's going on, but think about it from the perspective of the characters. How would we know who is correct? That's why I use the "you see
through the illusion routine" you can see that it's there, but it is semi-transparent and obviously an illusion of some sort.
Otherwise we get the old D&D illusory floor trick. In D&D some of the more powerful illusions can have the full range of senses, including touch. Up to the point where if you fail to resist the illusion of a floor, you can walk on it, because it feels like a real floor to you. This means that a floor made by this illusion is a reverse-trap. Succeeding at the resistance means that you fall, Failing means you're safe. But in D&D, you can choose to fail checks, so the sign that says "Have faith, and let yourself go" can actually be followed and you can choose to fail the Will save to resist the floors existence.
