Okay, new rules question:
What happens if your high level Sorcerer decides to layer on 5
mirror image spells prior to combat?
"The same spell can sometimes produce varying effects if applied to the same recipient more than once. Usually the last spell in the series trumps the others. None of the previous spells are actually removed or dispelled, but their effects become irrelevant while the final spell in the series lasts."
It seems that the number of active images of the last spell cast would be active as long as the spell duration goes on. That part's easy. The next part is the tough one: is mirror image considered to end as soon as the last image is destroyed? If so, then as soon as Spell N's images are destroyed, Spell N-1 pops up and is active. If not, then the caster has to take a Std action to dismiss Spell N before Spell N-1 will pop up.
Play balance-wise the first option is pretty scary. Five layers will give you 25-40 images or so with opponents having to get rid of 5-8 each round just to get a clear shot at the target underneath.
The second option is slightly better than casting the new mirror-image on the spot, since Dismissing a spell doesn't provoke an AoO.
So since I can interpret the rules either way, I'd suggest going with option #2. It does mean there are some odd useless dweomers around the target, which might confuse an arcane-visioned viewer, but otherwise is simpler.
any other thoughts out there?