I've been trying to find information on this, but everyone always asks about grappling someone else who is using Mirror Image, or being grappled while using Mirror Image. I want to know how effective it would be to grapple while using Mirror Image.
So you cast Mirror Image, then you Grapple someone. Let's say you manage to shove them prone as well. My thoughts on this are that they would then have disadvantage on attacks against you, and even if they hit, you could potentially direct the attack to one of the images.
One thing I've seen people point out is that if the attacker can perceive with something other than sight, then Mirror Image has no effect, and if you're Grappling, then they are "touching" you, thereby perceiving with something other than sight, but that doesn't make sense to me. A grapple could just be grabbing someone's wrist. The Mirror Image could show four people grabbing your wrist, all moving around confusingly. Only one is actually touching you, but unless you close your eyes, you'd get confused and just start hitting.
The character I've built already has Enlarge/Reduce and Expertise in Athletics. Mirror Image has no concentration, so it can work alongside Enlarge/Reduce. I just might not be able to get War Caster, and I'm looking for ways to avoid being hit after grappling to avoid loosing Concentration.
