Destroying Objects and Invisibility

[toranbazdrum]

The Invisibility Spell states that "the spells ends for a target that attacks or casts a spell" (PHB p254).

The Dungeon Master Guide, page 246/247 talks about Object Armor Class and Object Hit Points.

If an invisible player is trying to cut the noose of another player that was unfortunately strung up in the gallows, would it be considered an attack and therefore their invisibility spell ended?

TL/DR: Is trying to destroy an object considered an "attack" for mechanical purposes?

[Vogonjeltz]

The Invisibility Spell states that "the spells ends for a target that attacks or casts a spell" (PHB p254).

The Dungeon Master Guide, page 246/247 talks about Object Armor Class and Object Hit Points.

If an invisible player is trying to cut the noose of another player that was unfortunately strung up in the gallows, would it be considered an attack and therefore their invisibility spell ended?

TL/DR: Is trying to destroy an object considered an "attack" for mechanical purposes?

You have to make an attack roll, so yes.

[Breashios]

Anything that does damage is probably an attack (I don't have access to my PHB right now. If it is explicitly stated somewhere, of course, we just need someone to quote that for us.)

My question is, had this pc thought of (while invisible) untying the knot before the hanging commenced?

If it was a matter of changing the knot to some type of knot that would untie when any amount of pull against it was applied, the hangman might notice when putting it on, but some knots have a tug release, the invisible character might activate right before the floor was pulled out under his friend. I don't really know much about knots, but assuming character knowledge allowed for it...

[Ninja_Prawn]

would it be considered an attack and therefore their invisibility spell ended?

I also rule yes. This is what Greater Invisibility is for. Or, you know, a less violent solution.

[Demonslayer666]

As a DM I would not consider it an attack. You don't need to roll to hit when cutting an object under your direct control. You just put the knife up to it, hold the rope, and cut. There is no swinging.

I would consider this along the same lines as picking a lock, or interacting with an object.

edit:
There are things I would consider an attack when destroying objects, like throwing a vase.

[Laserlight]

If you're throwing a knife at it, it's an attack.
If you have the rope in your hand and saw at it with your knife, I'd probably allow it as not-an-attack, with my usual caveat "This does not create a precedent".
If you gently pour a vial of acid on the rope, I'd say that's not an attack.

[Millstone85]

The PHB, page 185, describes breaking an object as either an attack roll or a Strenght check.