The Monster Manual's entry for the Specter (p. 279) includes the Poltergeist variant, which has the Telekinetic Thrust action. The part I'm considering is (emphasis mine):
If the target is an object that isn't being worn or carried, the poltergeist hurls it up to 30 feet in any direction. The poltergeist can use the object as a ranged weapon, attacking one creature along the object's path (+4 to hit) and dealing 5 (2d4) bludgeoning damage on a hit.
From my reading, this should count as making an attack against a creature.
The rules on unseen attackers/targets include:
If you are hidden—both unseen and unheard—when you make an attack, you give away your location when the attack hits or misses.
So when using Telekinetic Thrust in this way, since it is an attack, it seems to me that the poltergeist would be giving away its location.
However, in the Curse of Strahd campaign, there is a poltergeist (minor CoS spoilers):
Chapter 13 (p. 194), Area X38, "Haunted Room":
The ceiling here is 10 feet high. A poltergeist (see the specter entry in the Monster Manual) haunts this room and telekinetically hurls broken furnishings at intruders so as not to give away its location.
So what's going on here?
- Is the adventure wrong?
- Is this a "specific beats general" case, that is, is this a special poltergeist?
- Was I wrong in the assumptions I made about poltergeists and telekinetic thrust?