What mechanics allow you to target an Unseen Servant?

Question

It appears that the spell unseen servant creates a shapeless force that is neither an object nor a creature. Because it does not fall into either of those categories, what mechanical options are there that can target and damage the unseen servant?

Answer 1

You target the location that it is in

Unseen servant is weird. Jeremy Crawford was asked directly, if it's not a creature or an object, then why does it have AC and HP? His answer was "it's exceptional" - as if that was an explanation!

So, how do you attack it if it is not a creature or an object? You attack the location that it is in. My answer here is actually a more explicit restatement of Guillaume F.'s answer to this question.

The rules for making an attack say:

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

Conclusion: we are permitted to attack locations.

The rules for attacking unseen attackers and targets say (emphasis mine):

When you attack a target that you can't see, you have disadvantage on the attack roll. This is true whether you're guessing the target's location or you're targeting a creature you can hear but not see. If the target isn't in the location you targeted, you automatically miss, but the DM typically just says that the attack missed, not whether you guessed the target's location correctly.

"If the target isn't in the location you targeted then you automatically miss." The implication here is that if the thing you would like to attack is in the location you targeted, then you can attack it (at disadvantage) even though it is not the target of your attack.

The verbal sleight of hand here is the key - mechanically, the target of your attack is the location - but if this location is correct, that permits you to attack your intended target, which was not itself the target of your attack. Thus, you don't need to be able to target the actual thing you want to attack, since you are permitted to attack it by targeting the location it is in. So long as it can be considered to be in a location, you don't have to target it directly.

In the case of an unseen servant, you are not permitted to make it the target of your attack since it is not a creature, object, or location. But crucially, the servant does exist at a point in space. If you can correctly guess its location, you can make that location the legal target of any attack that can target a location. And by targeting the location of the servant, you are permitted to attack it, even though it cannot be directly targeted by your attack.

Answer 2

By RAW target the caster and get them 60 feet away from the Unseen Servant. Pop!

Not many spells or items can target an Unseen Servant precisely for the reasons you stated, i.e. not a creature, not an item. However, the Antimagic Field spell might have an effect, in that the Unseen Servant could be considered magical. However, in the description of the spell it describes it as a "force". So, I think this will need to be a DM ruling rather than RAW.

It has an AC10 and 1 HP, so the suggestion is that it can be attacked, but possibly not targeted by any spells or abilities that mention specifically a "creature". It is indeed "tricksy" and will require a DM ruling here, too.

Related: Can an Unseen Servant be attacked?, and What forms of damage affect an Unseen Servant?

However, if you are unable to get to the Unseen Servant, you can target the caster instead. They will need to be no more than 60 feet from the Unseen Servant. As described in the spell, if it is "more than 60 feet away" from the caster, then the spell ends. So, physically moving the caster away from the Unseen Servant will end the spell and destroy it. Even if the caster commanded it to follow, it is likely going to be out of a 60-foot range pretty quickly as the Unseen Servant can only move up to 15 feet per turn. The PCs at our table often use grapple and Telekinesis quite creatively - this could be another instance.

Personally, I think the ultimate fun way to kill an Unseen Servant would be for a druid to wildshape into a Spider, chase it and bite it for a whopping 1 damage.

Answer 3

Up to the DM to decide

Unseen Servant's wording is notoriously vague and badly fitting into the other rules mechanics.

Precedent from other questions

Nevertheless, it is already established that you can attack Unseen Servant, with normal weapon attacks.

It might be up to the DM to judge if they allow a spell like fire bolt, that explicitly only targets a creature or object to attack the unseen servant. Since the language for attacks also only allows attacking a creature, object or location, and the consensus is that you can attack it, I would rule that since it has an AC, it can be attacked also by spells that attack creatures or objects.

It also can be damaged by area effects like a fireball, and as it only has 1 hp, this will end it. Again, fireball only says it damages creatures, and sets objects on fire. (One could also debate if torching the area with a fireball counts as targeting the servant, I'll say yes with a lowercase t for target, but in the end this is up the DM.)

In both these cases, Unseen Servant is hit by effects that hit objects or creatures, at least based on consensus of the community.

Evidence from the spell's text

The servant described as:

It has AC 10, 1 hit point

It is clear that the servant is intended to be easy to hit and to not withstand any damage. This would not make sense if attacks could not hit it or it could not take damage from effects.

Consequences of alternative readings

Having indestructible servants you can spam as ritual spells would likely be much more of a problem, especially with stupid monsters who do not realize they cannot harm a servant under a cloak, and in general using them as indestructible combat support.

Conclusion

Taking all these together, I think it makes most sense let it be damaged by anything that can damage a creature or object.

In our game, we handle it like that, and while I as the wizard would love me an indestructible servant, it makes sense for a level one spell and has not caused any problems.

Like in other cases where the rules text is ambigous or contradictory, in the end this is a judgement call by the DM how it works at their table.

PS

As Marq points out, there are also some spells which can explicitly target it, for example dispel magic, which can target a magical effect. Strictly speaking this is not "targeting and damaging" the servant, but it still would end it.