Pathfinder 1E Does Detect Thoughts break Invisibility? When?

[Sammael]

If an Invisible caster casts Detect Thoughts and then scans an area behind a closed door, would that break the Invisibility spell? Presumably, the caster has no idea what's behind the door - friends, foes, neutrals, etc.

 

[howandwhy99]

Extra Sensory Perception like Detect Thoughts falls under normal sensory perception rules. Seeing, hearing, smelling, and so on of another creature aren't treated attacks, so neither would D.T. or Detect Undead and probably most any other divination ability. But YMMV.

 

[CroBob]

If an Invisible caster casts Detect Thoughts and then scans an area behind a closed door, would that break the Invisibility spell? Presumably, the caster has no idea what's behind the door - friends, foes, neutrals, etc.

Which edition? Will it break his invisibility, or that of the people whose mind he's trying to read?

 

[Sammael]

Pathfinder, as I labeled the thread. I am referring to the caster's invisibility. As per the PF rules, for invisibility: "For purposes of this spell, an attack includes any spell targeting a foe or whose area or effect includes a foe". Detect thoughts is a spell whose area may include a foe, but the caster is not immediately aware of this at the time of the spell's casting.

 

[CroBob]

Pathfinder, as I labeled the thread. I am referring to the caster's invisibility. As per the PF rules, for invisibility: "For purposes of this spell, an attack includes any spell targeting a foe or whose area or effect includes a foe". Detect thoughts is a spell whose area may include a foe, but the caster is not immediately aware of this at the time of the spell's casting.

His invisibility failing might be a big hint that his spell effected hostile creatures.

 

[Bad Paper]

oo I hadn't seen this asked from the POV of an invisible caster! RAW says yes the caster loses invisibility.

What if the spell is detect magic? That, too, can include foes in its area, but there's no saving throw the way there is for detect thoughts.

 

[paradox42]

Intent is critical for judging whether something is an attack. If the caster does not know before casting DT that its area includes hostile creatures, then the caster stays invisible- because at casting time, as far as the caster is concerned, the AoE does not contain enemies.

If, however, the caster casts DT knowing in advance that the AoE includes hostiles within it, then the spell is an attack, and the caster becomes visible. In such a case, this is easy to justify, as the reason for casting DT on an area one knows to contain enemies can only be to see what those enemies are thinking (so as to better fight back).

 

[CroBob]

Intent is critical for judging whether something is an attack. If the caster does not know before casting DT that its area includes hostile creatures, then the caster stays invisible- because at casting time, as far as the caster is concerned, the AoE does not contain enemies.

If, however, the caster casts DT knowing in advance that the AoE includes hostiles within it, then the spell is an attack, and the caster becomes visible. In such a case, this is easy to justify, as the reason for casting DT on an area one knows to contain enemies can only be to see what those enemies are thinking (so as to better fight back).

I disagree that intent would really matter, here. To be fair to the PC, perhaps he could sense his invisibility fading as he's casting his DT, giving him the chance to cancel the casting before his invisibility fades and saving his DT. That, however, is a nice thing for a DM to do, not necessary or suggested.

 

[pemerton]

Intent is critical for judging whether something is an attack.

I disagree that intent would really matter, here.

I think I agree with CroBob, at least as far as the rules go, but maybe it's not crystal clear.

The rules say:

Invisibiity
The spell ends if the subject attacks any creature. For purposes of this spell, an attack includes any spell targeting a foe or whose area or effect includes a foe. (Exactly who is a foe depends on the invisible character’s perceptions.)

Detect Thoughts
Range: 60 ft.
Area: Cone-shaped emanation​

So first, to [MENTION=24674]Bad Paper[/MENTION], a saving throw doesn't matter: the criterion for an attack includes "a spell whose area includes a foe". This is true of Detect Thoughts, and would be true of Detect Magic also.

The key interpretive question is the meaning of "the invisible character's percpetions". Does that mean "standing dispositions to judge" or does it mean "present conscious awareness"? If the former, then someone is a foe if the caster would judge them such once s/he knew about them, even if s/he is currently ignorant of them. Conversely, if the latter than beings of whom the caster is not aware can't be foes.

Even if you go with the latter interpretation (which is more generous to the caster), it is not "intention" that would matter, but rather "knowledge/awareness".

The relevant spells in Rolemaster are similar, and so this problem came up in my game, but the spells are not identical. In particular, the spell that does the detecting part is separate from the spell that does the mind-reading part. The way I solved the problem was to treat the detecing spell as non-attack (so, for example, a psioniscist could turn invisible and scout around scanning for thinking beings) but to treat the mind-reading spell as a targetted attack (so using it would unambiguously break invisibility). Mind reading is, in my view, powerful enough that it doesn't need to be doable while invisible! Whereas invisible scouting is, for me at least, a reasonable part of the game.

 

[Matthias]

Intent is critical for judging whether something is an attack. If the caster does not know before casting DT that its area includes hostile creatures, then the caster stays invisible- because at casting time, as far as the caster is concerned, the AoE does not contain enemies.

If, however, the caster casts DT knowing in advance that the AoE includes hostiles within it, then the spell is an attack, and the caster becomes visible. In such a case, this is easy to justify, as the reason for casting DT on an area one knows to contain enemies can only be to see what those enemies are thinking (so as to better fight back).

This is splitting hairs...

"Exactly who is a foe depends on the invisible character's perceptions."

This ought to preclude, for example, an elf caster trying to lie to himself that those orcs behind the door won't attack on sight, because he still knows the truth that orcs are generally nasty creatures and would turn hostile if they were aware of him.

This also depends on what is meant by "foe". Does this mean currently having hostile intent, or the potential for it? Orcs could not harbor hostility toward a specific creature they aren't immediately aware of, but if orcs and elves generally don't get along, then the hostile intent may be present without the direct knowledge of the proximity of an elf caster, or even without any given orc currently dwelling on just how much they hate elves at that moment.

I'd probably do what CroBob suggests-

I disagree that intent would really matter, here. To be fair to the PC, perhaps he could sense his invisibility fading as he's casting his DT, giving him the chance to cancel the casting before his invisibility fades and saving his DT. That, however, is a nice thing for a DM to do, not necessary or suggested.

I would probably require some kind of die roll to drop the Detect Thoughts in time. Wisdom check, caster level check, Spellcraft check, something else?