D&D 5E Detect Thoughts as an interrogation tool

[prabe]

Heh - we have it that it does: the dead can't lie.

I don't remember: Is that a 1E thing (IIRC, you're running heavily-houseruled 1E), or is that one of your houserules?

It would give the threat I was responding to more teeth--if the dead couldn't refuse to answer (which might also be the rule in your game).

 

[Lanefan]

I don't remember: Is that a 1E thing (IIRC, you're running heavily-houseruled 1E), or is that one of your houserules?

I've honestly no idea - we've just played it that way since forever.

It would give the threat I was responding to more teeth--if the dead couldn't refuse to answer (which might also be the rule in your game).

Yes, most of the time the corpse is compelled to answer. On rare occasions one won't, usually meaning that corpse/spirit is getting some divine help from somewhere. Caster and corpse have to have shared a language (not everyone speaks Common!), failing that the caster also has to cast Tongues or - if double-classed with MU - Comprehend Language.

The one thing I keep having to remind people, though, is this: the dead corpse can't tell you things that the live corpse didn't know.

Edit to add: there's one other rare circumstance where a corpse won't answer, that being if destruction of the spirit/soul was the cause of death; because I've always had SWD as communicating with the spirit/soul which just "borrows" the corpse to speak through. If there's no spirit left then there's nothing there to talk to.