In Lamentations of the Flame Princess the classic Mirror Image spell it is given an interesting twist:
"This spell grabs 1d4 duplicates of the caster from near-identical timelines to confuse foes and make it more difficult for the original caster to come to harm. Since all of the mirror images are the caster, in the same situation and fighting the same battle in their own timeline, they are indistinguishable in every way from the caster and mimic his every motion." (LotFP: Rules & Magic, p. 117)
In other D&D variants* Mirror Image is usually treated as an illusion spell. Which is fine, but for reasons of WEIRD, the LotFP version holds many possibilities, reaching behind the mere use of the spell.
Magic is supposed to be dangerous, and have serious consequences, right?
If the mirror images are real people (from a different timeline), forced to appear next to the caster by foul sorcery, then when they die or take damage in their stead, well, that's real death and damage. Not many Magic-Users realize this dark feature, that by using Mirror Image as a parlor trick or to get out of some mundane trouble, they are actually eradicate themselves from "1d4 timelines".
So, if a Magic-User in your game casts Mirror Image often, as a Referee (DM) you can certainly introduce some creepy weird elements. Have the "eradicated alternatives" haunt the Magic-User in his/her dreams, or just flicker in and out of existence in their field of vision.
And what if the alternative timeline self casts Mirror Image? Does the Magic-User from your game get siphoned into the alternative timeline for the duration of the spell?
These are also good ideas for a Mirror Image miscast table...
* At least to my knowledge, this variation is included only in LotFP. Correct me if I'm wrong.
|"Which version of myself should I kill today?"|