Now here's a question about Mirror Image and Magic Missile.
Magic Missile can only target a creature. A Mirror Image is a figment, not a creature.
Is someone casts Magic Missile, and the random roll to determine what is targetted indicates one of the images... shouldn't the Magic Missile fail for having no valid target?
The spell description says the images react normally to area spells, and any successful attack roll destroys one... but Magic Missile is not an area spell, and requires no attack roll.
I'd think if you split your four missiles, say, across four potential images, three of them would fizzle, and one (aimed at the true caster) would behave normally... and bounce off the Shield spell. But at least then your allies know which one to Smite until the caster's next action...
-Hyp.