Does the Confusion Spell Affect Ghosts that are Possessing a Character?

Question

Let me lay out the scenario: I'm running a D&D 5e session where the party enters a haunted castle and begins snooping around. They encounter four ghosts and one of the PCs gets possessed by a ghost. After a few rounds of combat, the Druid decides to cast Confusion on an area that the possessed PC is in. I know the following things:

1. Ghost possession rules state that the Ghost cannot be targeted by attacks or spells unless the attack or spell turns undead.

2. Confusion "targets" an area, not individual creatures (based on my understanding of what "target" means) so the possessing Ghost isn't targeted but in the area of effect.

3. Ghosts are not immune to Confusion because although they are immune to being charmed, Confusion does not state in its description that creatures immune to being charmed are immune to the spell.

4. If the spell were a fireball or lightning bolt or a different AoE spell, the ghost would be unaffected and the spell would simply harm the vessel.

The party argued that this would mean that the ghost can be affected, especially since the ghost is acting as the PC's mind. Since they were in a tough spot, I decided to allow it this time, but I told them I'd reach a decision about that sort of thing after doing some research.

Here is my question: Would a ghost possessing a PC be affected by a Confusion spell? My instinct is to think that the Confusion spell hits the PC instead of the ghost and since the PC is incapacitated, the spell basically has no effect.

Answer 1

The Ghost is unaffected by the Confusion spell. While there is no strong statement that all creatures affected by a spell are "targets" of the spell, I did find this on page 205 of the PHB:

Many spells specify that a target can make a saving throw to avoid some or all of a spell's effects. The spell specifies the ability that the target use for the save and what happens on a success or failure.

This seems to imply that the targets of a spell are any creatures affected by it, although it's obviously not as clear as we could hope. Another example, on page 196:

If a spell or other effect deals damage to more than one target at the same time, roll the damage once for all of them. For example, when a wizard casts fireball or a cleric casts flame strike, the spell's damage is rolled once for all creatures caught in the blast.

As backup for this, we have the Ghost's Possession ability on page 147 of the Monster Manual:

The ghost can't be targeted by any attack, spell, or other effect, except ones that turn undead[...].

Turn Undead is an AOE ability, not a targeted one. If the Ghost was still meant to be affected by AOE spells and abilities, the caveat for Turn Undead would not be necessary.

And finally, if AOE spells did affect a Ghost in the midst of possessing someone, the Ghost would be affected by every Fireball or Lightning Bolt that hit the possessed creature. In your fourth point, you asserted that this obviously wasn't the case, which I agree with. There's no reason why Confusion would work differently than every other AOE spell.

Answer 2

You're right, your players were wrong. See Miniman's answer. I've revised accordingly.

What we have for "target":

A typical spell requires you to pick one or more targets to be affected by the spell's magic. A spell's description tells you whether the spell targets, creatures, objects or a point of origin for an area of effect (described below).

Areas of effect are defined thusly:

Spells such as burning hands and cone of cold cover an area, allowing them to affect multiple creatures at once.

Miniman found the references which clarify the meaning of "target" to include all things affected by the spell:

Many spells specify that a target can make a saving throw...

and

If a spell or other effect deals damage to more than one target...

And the Ghost's possession ability reads (in part):

The ghost can't be targeted by any attack, spell, or other effect, except ones that turn undead...

Thus the Ghost's inability to be a target means that it's unaffected by the spell. It would be clearer if the possessing Ghost were unaffected by spells that don't turn undead, but hey, we work with what we have.

Answer 3

One small caveat.

The ghost would be unaffected, but the PC would.

Notes on Possession: "One humanoid that the ghost can see within 5 ft. of it must succeed on a DC 13 Charisma saving throw or be possessed by the ghost; the ghost then disappears, and the target is Incapacitated and loses control of its body. The ghost now controls the body but doesn't deprive the target of awareness. "

Confusion lasts for 1 minute. If the ghost were to uninhabit the creature suddenly, and the player maintained concentration (willfully) it would still be confused when it was removed, presuming it survived the process. It'd make its initial saving throw against confusion when cast, possibly resulting in an automatic failure due to it being incapacitated, and then would most likely resume the confusion effect once the ghost was gone from its form.

So it would do something and not entirely negate the spell's purpose.

I'm not sure how the ruling of "awareness" would matter during confusion. It's possible that the moment the ghost was released the pc would resolve a confusion affect on its first free turn.