Inspired by What happens if I try to grapple an illusory duplicate from the Mirror Image spell?, what happens if I successfully grapple the wizard, rather than targeting one of the duplicates? Is the wizard's spell negated because I'm grappling him?
Mirror image states:
Three illusory duplicates of yourself appear in your space. Until the spell ends, the duplicates move with you and mimic your actions, shifting position so it's impossible to track which image is real.
The illusory duplicates are of yourself, not others, so couldn't my allies just target the one I'm holding?
Best Answer
No
The mirror image rules still apply because the spell is still active. The 'fluff' or narrative of description of why is up to the DM.
The only ways to bypass are if you aren't making an attack roll or if it is dispelled /suppressed.
Narrative example
To help give some substance to this, a possible description I would use is:
Table Reasons not to allow it
I'd also heavily consider what it would mean to allow grappling to negate the spell effect. If it's a player casting it, they've just used up a 2nd level slot to do so (which could be very impactful depending on the level of the caster). It's less of an issue for later, but resources are resources.
It also starts to open up potential other issues for why do some things work against it and others not.
Letting the spell do its job is both within the rules and makes good sense.