Can the image from Mirror Image be a target of an attack or effect?

Question

The mirror image spell description says

Each time a creature targets you with an attack during the spell's duration, roll a d20 to determine whether the attack instead targets one of your duplicates.

It does not prohibit targeting the illusory duplicate themselves, especially for a non-hostile effect.

Two examples from features with a similar effect are:

The Goblin Boss (MM, p. 166) has the Redirect Attack reaction:

When a creature the goblin can see targets it with an attack, the goblin chooses another goblin within 5 feet of it. The two goblins swap places, and the chosen goblin becomes the target instead.

The Way of the Drunken Master monk's 6th-level Tipsy Sway feature also grants a benefit named Redirect Attack (XGtE, p. 34):

When a creature misses you with a melee attack roll, you can spend 1 ki point as a reaction to cause that attack to hit one creature of your choice, other than the attacker, that you can see within 5 feet of you.

Note that those are just examples. The point of the question is whether the duplicates can be targeted by such attacks or effects, either knowingly or unknowingly it's a duplicate.

Also note that most non-attack effects simply bypass mirror image by directly affecting the mirror image user. However, for other effects, this question asks about the more fundamental principle: whether the duplicates are actually targetable or not.

A point of consideration might be whether an effect that specifies a creature as its target is unable to target mirror image's duplicate - or whether any effect is simply unable to target the duplicate, and could only target the original target.

Answer 1

The duplicates aren't creatures

Per the mirror image spell description:

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.

Nothing in the spell description says the duplicates are creatures - they're just illusory copies of you.

...But attacks can always be redirected to them regardless

The description continues (emphasis mine):

Each time a creature targets you with an attack during the spell's duration, roll a d20 to determine whether the attack instead targets one of your duplicates.

If you have three duplicates, you must roll a 6 or higher to change the attack's target to a duplicate. With two duplicates, you must roll an 8 or higher. With one duplicate, you must roll an 11 or higher.

Anytime you're targeted by an attack while mirror image is active on you, the spell can redirect the attack to one of your duplicates. The spell makes no exceptions regarding whether the attack can only target creatures.

As the intro to the PHB/basic rules states:

Specific Beats General

This book contains rules, especially in parts 2 and 3, that govern how the game plays. That said, many racial traits, class features, spells, magic items, monster abilities, and other game elements break the general rules in some way, creating an exception to how the rest of the game works. Remember this: If a specific rule contradicts a general rule, the specific rule wins.

It's because "specific beats general" that any attack that targets you, even if it normally can only target a creature, can be redirected to a duplicate as well.

The duplicates can't be intentionally targeted, either

The illusory duplicates can't be intentionally targeted separately from you. As the first quoted pair of sentences state, it's impossible to track which image is real because they move with you and mimic your actions. Thus, anything that would attempt to target your duplicate would necessarily have to be trying to target you - which of the "duplicates" actually turns out to be you is determined randomly by rolling a d20.

Anything that's not an attack doesn't interact with the duplicates

A later part of the spell description says (emphasis mine):

A duplicate's AC equals 10 + your Dexterity modifier. If an attack hits a duplicate, the duplicate is destroyed. A duplicate can be destroyed only by an attack that hits it. It ignores all other damage and effects. The spell ends when all three duplicates are destroyed.

As the spell itself states, the illusory duplicates have no mechanical interaction with things that aren't attacks - whether it's a spell requiring a saving throw, a non-attack monster ability, a class feature, or something else. Unless it's an attack, it doesn't interact with the spell at all.

(Note: grapples/shoves are "special melee attacks", so they can be redirected to the duplicates - but since they don't have attack rolls, they can't "hit" the duplicate and simply fail if redirected to a duplicate.)

Answer 2

Depends on the effect, but probably no

Both Goblin Boss and Tipsy Sway requires a creature:

the goblin chooses another goblin

hit one creature of your choice

Illusory duplicates from the Mirror Image are not creatures, so, by the rules as written, you can't target them.

Illusions are magic effects, not creatures neither objects, so they can't be targeted by spells or features that require a creature or object as a target. However, they can be targeted by the Dispel Magic spell, since it specifically can target a magic effect.

Answer 3

The only things that target spell effects directly can target the mirror images.

E.g. dispel magic targets spell effects

Choose one creature, object, or magical effect within range