What forms of damage affect an Unseen Servant?

Question

Related to this question, what forms of damage affect an Unseen Servant?

1. Physical types: bludgeoning, piercing, slashing.
2. Magical forms of the physical types.
3. The other types, some of which are always magical, while others can be magical or mundane in nature:

Acid, Fire, Cold, Poison, Necrotic, Radiant, Lightning, Psychic, Thunder and Force.

4. Falling damage (a special type of bludgeoning, related to this question).

My musings:

• As a "mindless" entity, it makes sense a Servant cannot take psychic damage.
• Acid, Fire, Cold, Lightning, and physical damage hinge on whether the Servant has a "body" or not (see the first link).
• Poison seems like a no, as the Servant certainly doesn't breathe and has no means of absorbing the poison.
• Necrotic and Radiant are harder to define, as those damage types are themselves open to interpretation.
• Thunder seems like a no, as it has no hard body to damage with vibrations and doesn't appear capable of hearing anything.
• Force seems like a yes.
• Fall damage is highly dependent on the answer to the second link.
• Since a Servant cannot move through objects like spectral creatures, it seems unlikely a magical weapon would be any different than a regular weapon.

Answer 1

The spell description does not indicate any resistances nor any immunities. It takes up some space and is made of force. All it needs to do is take one HP of damage and it drops to 0. How to target it would be situation dependent.

Therefore, all forms of damage cause damage to an Unseen Servant. The only form that is arguably not applicable is psychic damage, as the Unseen Servant is mindless, and no stat is offered for intelligence.

If it were within the blast radius of a fireball, game over.

Insofar as Cold damage is concerned, feeling cold isn't the issue. Cold damage being a damage type means that cold can damage it in terms of game mechanics. (Cold makes metal and glass more brittle ... and when we get to "does a mindless entity feel" we once again find that the rules are silent).

Bludgeoning, Piercing, Slashing. Acid, Fire, Cold, Poison, Necrotic, Radiant, Lightning, Psychic, Thunder and Force.

At least 12 of the 13 apply to it. Whether or not Psychic damage affects the Unseen Servant is a DM ruling.

Answer 2

No immunities are mentioned in the spell description. However, the Unseen Servant is neither an object or a creature, but instead a shapeless force.

As such, it is immune to most spells, including:

Fireball

Each creature in a 20-foot radius Sphere centered on that point must make a Dexterity saving throw. A target takes 8d6 fire damage on a failed save, or half as much damage on a successful one.

The fire spreads around corners. It ignites flammable objects in the area that aren't being worn or carried.

Firebolt

You hurl a mote of fire at a creature or object within range.

Magic Missile

You create three glowing darts of magical force. Each dart hits a creature of your choice that you can see within range.

Because the Unseen Servant is neither a creature nor an object, it is unaffected by those spells.

Answer 3

Any form of damage affects an Unseen Servant. The question is how do you target it?

This is a surprisingly difficult question to answer RAW.

First, the spell "creates an invisible, mindless, shapeless, Medium force". The spell does not say anything about damage resistances or immunities. Therefore it has no damage resistances or immunities.

Compare with wall of force:

An invisible wall of force springs into existence at a point you choose within range. […] It is immune to all damage and can't be dispelled by dispel magic. A disintegrate spell destroys the wall instantly, however.

Since unseen servant doesn't say it is immune (or resistant) to any damage types, it is not immune (or resistant) to any damage types.

The unseen servant has an Armor Class (10) and hit points (1). This strongly implies that it can be targeted by an attack and take damage, else why provide this information? So, how do we target it? PH p. 193-4:

Whether you're striking with a melee weapon, firing a weapon at range, or making an attack roll as part of a spell, an attack has a simple structure.

1. Choose a target. Pick a target within your attack's range: a creature, an object, or a location.

As pointed out in a comment, Jeremy Crawford tweeted that the unseen servant is not a creature or object. The full tweet thread is worth quoting:

Jeremy Crawford @JeremyECrawford An unseen servant is "an invisible, mindless, shapeless force" (from the spell). It's not a creature. #DnD

Dr. Denica Bozhinova @atealein · Dec 19, 2017 Replying to @JeremyECrawford If it is not a creature, nor an object but a "force" why the specifics of the AC and hit points.. since most effects in the game damage creatures or objects only?

Jeremy Crawford @JeremyECrawford · Dec 19, 2017 It’s exceptional. Spells are tricksy that way.

Josue Pineiro @JoshPineiro1 · Aug 22, 2018 Replying to @JeremyECrawford Thanks for the clarification!

Per the Player's Handbook, attacks can target a creature, object, or location. Crawford says the force created by unseen servant is not a creature or object. I am pretty sure it is not a location. If we follow this logic through, the force cannot be targeted by an attack.

If this seems ridiculous to you, you're not the only one. I have to assume that @JoshPineiro1's "Thanks for the clarification!" at the end of the tweet thread is intended as sarcasm.

On the other hand, if you look at the history of the spell you find the following from AD&D:

It has no attacks, and cannot be targeted by attacks itself. It can be magically dispelled, or, if caught in an area spell, is eradicated if it takes 6 points of damage.

And this from D&D 3.5 d20 SRD:

It cannot be killed, but it dissipates if it takes 6 points of damage from area attacks. (It gets no saves against attacks.)

So at least in earlier editions, the unseen servant could not be targeted by attacks.

Therefore, the DM has a choice:

1. Decide that the force is not a creature, object, or location, and therefore cannot be targeted by any attack, which is consistent with previous editions.
2. Decide that since the force has an Armor Class, it can be targeted by an attack. In this case, I would not treat spells differently than physical attacks, as I do not think the fact that fire bolt says you must fire it "at a creature or object within range" means anything other than you must use the normal rules for targeting an attack. Either physical and spell attacks can both hit it, or neither physical nor spell attacks can hit it.

But I am 100% certain that if you can target it, you can damage it.

Answer 4

Area of Effect Spells/attacks might be the only things to affect it

The PHB states on page 284 that it creates:

[...] an invisible, mindless, shapeless force[...]

This is important. Invisibility would imply that no one can normally see it. The mindless is just that it is not intelligent. HOWEVER, the shapeless part is where it kicks in. It has the fact that it has no shape, so it would be similar to someone using 'the force' to move or do things. The lack of shape would imply that it has no tangible form, and cannot be targeted by attacks, which would exclude it from most spells. But as I said before, attacks that target a general area would not necessarily have this limitation, as it requires a save from those in the area that it affects, rather than having to target, in essence, an untargetable creature. The reason it cannot be targeted is quite simple: It has no shape. the word shapeless is defined as having no shape, so you can't target a cloud, or a humanoid body, or a creature form of some sort.

Answer 5

Unseen Servant is not affected by any form of physical attack. It is 100% force with no physical form, so there's nothing there to see, touch or attack. It is a very old spell that dates back to the beginning of D&D. If it had been designed to take damage it would have hit points and an AC, which it doesn't.

Unseen Servant can be Dispelled, or taken down by other magic-nullifying effects, but that's about it.