What happens when you use a projected image to cast a teleportation spell on another creature?

Question

The spell Project Image creates a shadowy duplicate that the caster can use to deliver spells.

If you desire, any spell you cast whose range is touch or greater can originate from the projected image instead of from you. The projected image can't cast any spells on itself except for illusion spells. The spells affect other targets normally, despite originating from the projected image.

If the caster loses line of effect by teleportation, then the spell ends.

If you use dimension door, teleport, plane shift, or a similar spell that breaks your line of effect, even momentarily, the spell ends.

What happens if, using the shadowy duplicate as the spell's origin, you cast a teleportation spell that targets other creatures? Does the Project Image effect end immediately, thereby preventing the teleportation effect from happening? Or does the teleportation effect happen first, and then the image goes away?

Example:

Bob the barbarian is in melee combat, and in trouble. Alice the wizard is a safe distance away, and she sends her shadowy duplicate over to him. On Alice's next turn, she casts Dimension Door from the projected image, in attempt to touch Bob and bring him to Alice's location.

Does the projected image immediately disappear, leaving Bob stranded in the front lines? Or, does the image disappear once the Dimension Door has taken effect, i.e., once Bob has been teleported to Alice's location?

Answer 1

The image can't cast dimension door.

One of the lines of project image that you've listed says "The projected image can't cast any spells on itself except for illusion spells." Dimension door has a Target of "you and touched objects or other touched willing creatures". Ergo, since dimension door has a Target of "you", and isn't an illusion spell, Alice can't cast it through her image.

Since dimension door always teleports the caster as well as possibly teleporting another target, the correct way to interpret the admittedly-ambiguous phrasing "you and touched objects or other touched willing creatures" is "You. Additionally, touched objects or creatures." There is no way to cast dimension door in a way that doesn't affect "you", so it will always have a target of "you", and thus be un-castable by a projected image.

Answer 2

As you stated,

The projected image can't cast any spells on itself except for illusion spells.

DuckTapeAl points out that Dimension Door is not an illusion spell, and so, because the target is "you and touched objects or other touched willing creatures", it cannot be cast by the projected image upon itself.

Note: I'm interpreting this as casting Dimension Door on "(you) + (creatures and/or objects) that you touch".

Additionally, "intangible" means "not touchable", and so logically it also cannot touch other things, meaning it would be unable to touch Bob to cast the spell on him. Alice herself is however far away, and certainly can't touch Bob either.

---

Regarding Line-of-effect, If you found a spell that allows teleportation without requiring touch, I would interpret it as such (assuming that the Image is also being moved):

So long as the teleportation is instantaneous, and line-of-effect remains at both the start and destination, it can be considered unbroken.

If the teleportation is not-quite-instant (or longer), as long as line-of-effect remains for the entire path of the teleportation (a straight line from start to destination), it can be considered unbroken.

If the line-of-effect is broken for some reason, then it must occur after the teleportation initiated, and so the Projected Image would be lost "in transit". Despite the Image being the source of the casting, the actual power is being provided by Alice, and so Bob should probably arrive safely, even if the Image disappears en-route.

Answer 3

You need special spells for this

As other answers have mentioned, you can't use dimension door for this, because it self-targets (and, if it somehow doesn't self-target, then there's no LoE issue). You can still do this, though, you just need Shadow Walk or similar spells that let you teleport via illusion magic instead.

The spell ends after the teleportation is initiated

We know that the teleportation has to at least start before the spell ends, because losing Line of Effect is what makes the spell end. Spells don't end just because their caster no longer exists, but be aware that they might behave differently due to your duplicate ceasing to be immediately after they come into effect. For example, if you use Shadow Walk to save your buddy, he has a 50% to wander off into the Plane of Shadow on account of your clone left.