Twin Spell and Illusions

[JumboWheat01]

Simple question, could you use Twin Spell along side Minor Illusion, Silent Image or Major Image?

[Hellpyre]

No for all of those options - none of them target creatures, much less a single creature specifically.

[Segev]

You COULD use it for phantasmal force, though.

[JumboWheat01]

Fair enough. Never hurts to double check these things.

[Aimeryan]

Hmm, a more interesting question is, could you target a Twinned spell (say, Firebolt) at an illusion that appeared to be a creature? Twinned has such strict requirements (honestly, for the edition that labels itself as simple, Twinned is anything but) that if JC is to be believed it makes it so that a spell that is cast on a single creature can't be Twinned (Dragon's Breath) - so what happens when the target is not actually a creature but an illusion?

[jojosskul]

Hmm, a more interesting question is, could you target a Twinned spell (say, Firebolt) at an illusion that appeared to be a creature? Twinned has such strict requirements (honestly, for the edition that labels itself as simple, Twinned is anything but) that if JC is to be believed it makes it so that a spell that is cast on a single creature can't be Twinned (Dragon's Breath) - so what happens when the target is not actually a creature but an illusion?

Silent Image and Major image state: You create the image of an object, a creature, or some other visible phenomenon

Since it is an image of a creature, in my opinion targeting it works just like targeting a creature normally would. So in this case, twin would go off but then if it hits you now know it is an illusion.

Minor Illusion states you create the image of an object or a sound. So Twin would fizzle, but that wouldn't necessarilly break the illusion. You'd realize the thing you were targetting was a cleverly disguised statue of a gnome and not a real gnome, for example.

[Segev]

Silent Image and Major image state: You create the image of an object, a creature, or some other visible phenomenon

Since it is an image of a creature, in my opinion targeting it works just like targeting a creature normally would. So in this case, twin would go off but then if it hits you now know it is an illusion.

Minor Illusion states you create the image of an object or a sound. So Twin would fizzle, but that wouldn't necessarilly break the illusion. You'd realize the thing you were targetting was a cleverly disguised statue of a gnome and not a real gnome, for example.

The image of a creature (or, indeed, anything else) is an effect, not a target, of the spell.

[jojosskul]

The image of a creature (or, indeed, anything else) is an effect, not a target, of the spell.

On further though I'll concede that, but it can still be targeted. The target is just, by it's nature, invalid. I did some digging and there's a technically optional rule in Xanathar's that I think clears this up.

Pg 85 - 56

"If you cast a spell on someone or something that can’t be affected by the spell, nothing happens to that target, but if you used a spell slot to cast the spell, the slot is still expended. If the spell normally has no effect on a target that succeeds on a saving throw, the invalid target appears to have succeeded on its saving throw, even though it didn’t attempt one (giving no hint that the creature is in fact an invalid target). Otherwise, you perceive that the spell did nothing to the target."

Based on this, you'd use twin, one of your two targets would be an invalid target but the twin would still go off. The firebolt would go through the illusion and potentially hit the real target, and the sorcery point is still expended. If the spell was say, Toll the Dead, it would just seem like the second target had auto saved on their saving throw.

It's not something you'd have to use in your game since it's an "optional" rule, but I think it clears up a lot of the ambiguity.

But you're right, an image of something doesn't make it actually that thing, so it's an invalid target. I was wrong on that bit. But the chain of events using this rule would still have the spell occur.

[Hellpyre]

The image of a creature (or, indeed, anything else) is an effect, not a target, of the spell.

Just in case it was unclear, the post you quoted was talking about targetting the image with one part of a different spell to be twinned, not trying to twin the illusion.

[Segev]

Just in case it was unclear, the post you quoted was talking about targetting the image with one part of a different spell to be twinned, not trying to twin the illusion.

Oh! I did misunderstand, then. My apologies.