If a spell has material components that are normally consumed, would casting that spell on an invalid target still cause them to be consumed?

Question

This question piqued my curiosity and prompted me to wonder about this issue: "Can True Resurrection be used to raise a creature whose body is still intact, but not within the range of touch?"

(Another older related question: "What happens when a caster targets an object that looks like a creature with a spell that targets only creatures?")

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The issue of what happens when you cast a spell on an invalid target was initially unanswered by the PHB or DMG. Xanathar's Guide to Everything eventually provided an optional rule to address this question (p. 86, under "Invalid Spell Targets"):

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.

(The answer to the question "Does a wand lose a charge if it attempts to target an invalid target?" suggests that just as a spell slot would be expended if cast using a spell slot, a charge would be expended if casting from a wand (or other magic item that used charges to cast spells).)

However, this still leaves something unclear:

What happens to material components that would normally be consumed, if the spell target is invalid? Are they still consumed?

For example, take a look at true resurrection, as in the case of the question that inspired this one:

You touch a creature that has been dead for no longer than 200 years and that died for any reason except old age. If the creature's soul is free and willing, the creature is restored to life with all its hit points.

The spell's material components are:

(a sprinkle of holy water and diamonds worth at least 25,000 gp, which the spell consumes)

What if the creature has been dead for over 200 years, or it died of old age? What if its soul is not free or willing? Would the 25,000 gp worth of diamonds still be consumed?

The question applies to any spell with consumed components, whether they are costly or not.

Answer 1

Yes. The materials were/are consumed.

The spell has been cast. Whether or not it had a successful effect does not matter. Only that the spell had been cast in its entirety.

Answer 2

Yes, the components are consumed.

Consider when you Ready a spell. Per the description:

When you ready a spell, you cast it as normal but hold its energy, which you release with your reaction when the trigger occurs. To be readied, a spell must have a casting time of 1 action, and holding onto the spell’s magic requires concentration. If your concentration is broken, the spell dissipates without taking effect.

Casting the spell and "releasing the energy", or making the magic happen, are two separate acts. So if the spell slot has been expended, the spell has been cast. It is only after that, unless otherwise documented, that affect can or cannot occur.

A more concrete example would be something like legend lore, which has a 10 minute casting time. During which you need to burn 250gp worth of incense. If you are interrupted during that time, the incense would not unburn itself.

Answer 3

Yes, the components are consumed

This question is similar to this one, in that the spell is without effect after its casting has been completed.

It is stated that components are consumed by a spell once that spell is cast, as is the spell slot used to cast the spell. This is regardless of whether or not the spell has any effect on its target, which is what the ruling in XGtE is meant to clarify.

Therefore, unless there is something that specifies that the spell slot is returned, the material components should be consumed as well once the casting is completed.

However,

A ruling made by Perkins in a very similar situation during a game of Acquisition Inc. goes contrary to this. During the game, Omin Dran attempted to cast Raise Dead (requiring a diamond worth 500 gp) on both of his sisters, who unbeknownst to him had their souls captured by Acererak. He cast the spell and it failed, and Perkins specified that the diamond used in the casting was not consumed, but instead grew "dark". This game, it should be said, was not known for following the rules too closely, and I'm uncertain if it can truly be used as a reference.