I've played EotE for quite a long time but something that I've been unsure on is how a PC can do the equivalent of an Insight check on an NPC, from something like D&D.

I'm assuming it's a Discipline check opposed by I guess Deception or Charm. But the thing that bothers me is that the NPC isn't actively being deceptive, or charming. The NPC is just being themselves and the PCs are trying to figure them out. So it makes me wonder what sets the difficulty of the check.

Has anyone any thoughts on this?

No roll is needed in that situation.

I think this is a good place for the lesser-used (besides for initiative) Vigilance skill.

Aye, Vigilance can be used to determine general deminor, though I wouldn't use checks frequently in this manner, I want the PC's to try and figure out their NPC's logically if it exists.

I think this is a good place for the lesser-used (besides for initiative) Vigilance skill.

And I think the check would be opposed by the target's Deception or Discipline skill, depending on if they're telling the truth or lying. You don't need to tell your players which.

Aye, Vigilance can be used to determine general deminor, though I wouldn't use checks frequently in this manner, I want the PC's to try and figure out their NPC's logically if it exists.

I think having a check can make sense, because some characters may be quite clueless with inter-personal skills whilst others might be quite aware of what's going on. I guess it's player vs. character skills.

I'd suggest either Perception (actively looking for tells that the NPC is lying) or Vigilance, with Perception being very obvious and could well lead to some penalties on social checks, especially if threat/despair is generated.

However, the problem (which can come up with Sense Motive-type skill checks no matter the system) is that you'll have players assume a certain outcome just based upon the fact that they're rolling. I've seen a couple campaigns derailed because one PC was convinced a key NPC was a lying villain simply because he rolled fairly well on the skill check, yet was told that said NPC does seem to be entirely on the up-and-up, and assumed the NPC simply had a better Deception check result.

For me this is compounded because I do all rolls openly. So if I allow a Perception/Vigilance/Discipline/Cool roll (I've used all these, depending on the situation), the negative dice can give a lot away. I also don't stick strictly with the NPC's abilities here. If they aren't lying, then the PC isn't rolling against Deception, they're really only rolling to see if they misinterpret the situation. That's how I used to do it.

But none of this was satisfactory, so now I just avoid this by playing it straight up. The purpose of rolling is to get information , not just determine a binary lying/not lying result. So if the NPC is being truthful I just tell the players he is. If the NPC is using Deception, then I make it pretty clear he's avoiding something, withholding something, or being generally duplicitous. Then the point of the rolling is to find out why. Success isn't just a "yep he's lying, now what?" result. Success gets an answer, at least one thing the NPC wished to be hidden is now available. Then the narrative results can be used to add further information, or in the case of Threats/Despair, some kind of misinterpretation that creates a challenge.

Really it's no different than searching a room. If there's nothing to find, just hand-wave it and move on. If there is, then the roll determines the quality of the information.

Dupe post

I'd suggest either Perception (actively looking for tells that the NPC is lying) or Vigilance, with Perception being very obvious and could well lead to some penalties on social checks, especially if threat/despair is generated.

However, the problem (which can come up with Sense Motive-type skill checks no matter the system) is that you'll have players assume a certain outcome just based upon the fact that they're rolling. I've seen a couple campaigns derailed because one PC was convinced a key NPC was a lying villain simply because he rolled fairly well on the skill check, yet was told that said NPC does seem to be entirely on the up-and-up, and assumed the NPC simply had a better Deception check result.

It sounds like that would have happened without a roll, anyway.

I think players being suspicious about a genuinely benign NPC (or vice versa) can be great fun too.

This came up in a game I'm running. The player wanted to "read" an NPC ala Sherlock Holmes and there was some debate as to what skill(s) would be appropriate and what results they might be able to get. I ended up ruling that a successful Perception check would reveal pertinent details (simultaneously filtering out unimportant or unindicative stuff) from which the player could either make inferences based on how their character thinks, or else employ Knowledge checks to connect clues to conclusions. I can't remember what skill I used to oppose it in that instance, but I could see Deception, Discipline, or Vigilance being applicable, reflecting either a character attempting to send false signals, keep a poker face, or else being fastidious enough to avoid carrying traces of where they've been or what they've been doing, respectively.