Passive investigation significantly higher than passive perception

[Slipjig]

I'm trying to figure out how a high passive Investigation interacts with a much lower passive Perception.

The character generally isn't paying attention, but when he does pay attention he sees how all the clues fit together?

He instinctively notes objects and understands their significance, but is oblivious to people?

[kingcheesepants]

Being oblivious to people would be having bad insight. Bad perception means you don't notice your physical surroundings for whatever reason, maybe you have bad eyes or maybe you're focused on something else and don't notice things. Good investigation means that you can reason out what things mean well.

If you have high passive investigation but low passive perception I'd probably play it as being short sighted (as in needs glasses) and maybe a little hard of hearing but good at reasoning out what things mean. So they're likely not to physically see or hear a thing but they do notice small details and can deduce what those details point to. So for example they don't notice the tiny crack behind the bookcase that the high perception person notices but they do notice that one of the books on the shelf doesn't fit in and can figure out that there's a hidden entrance based on that.

[Yora]

When would passive investigation even come into play?

[Mastikator]

When would passive investigation even come into play?

When the DM wants people to roll for investigation without asking for a roll. Like clues hiding in plain sight, or a secret message masquerading as an irrelevant text.

[Khrysaes]

When would passive investigation even come into play?

When you take the observant feat. At least as far as i recall that is the only time it is mentioned.

The skills may be more misnamed? Or maybe not.

So insight -> empathy, understanding people’s emotions and expressions.
Perception -> processing the senses, so understanding what you sense is. i.e. that green and brown blob is a tree.
Investigation-> making connections between things perceived?

So to notice the runes around the room? Perception. Connect the runes to unlock a hidden door or puzzle, investigation.

[Maan]

When would passive investigation even come into play?

Yup, I too find Perception and Investigation to be pretty poorly defined.
I would say Perception is for noticing something, while Investigation would be used to make deductions, research and the like... but then I don't see how you would use it passively.

[MoiMagnus]

I'm trying to figure out how a high passive Investigation interacts with a much lower passive Perception.

The character generally isn't paying attention, but when he does pay attention he sees how all the clues fit together?

He instinctively notes objects and understands their significance, but is oblivious to people?

IMO, passive Investigation is about having a good "routines". It's about touching walls to check for fake walls without even thinking about it. It's about interacting with objects in a way that reduces your chances of suffering the effects of an hidden trap. It's about being at the good place at the good time to get the information you need. So unless the secret is actually physically difficult to perceive (like it is far away and you barely see it, or you're under time pressure), finding something is more about investigation than perception.

On the other hand, passive Perception is for when something can be perceived without any particular method, but actually noticing it is not trivial.

Said otherwise, if you're trying to sneak behind a guard, it's against their passive perception (a guard with high passive perception will hear you come). If you're trying to sneak at a moment a guard is not there, it's against their passive investigation (a guard with high passive investigation will not follow an unpredictable pattern, and will never turn their back to place where someone could be hidden).

EDIT: as always, the problem with Investigation is the same as with most Intelligence skills, which is that sometimes it is the player's intelligence and skills that are used (cf players describing the paranoiac behaviour of their character and explaining how they plan to avoid traps, where they search for secret passages, etc) making the character's intelligence and Investigation skills redundant if not useless.

[LudicSavant]

Yup, I too find Perception and Investigation to be pretty poorly defined.
I would say Perception is for noticing something, while Investigation would be used to make deductions, research and the like... but then I don't see how you would use it passively.

“Passive” rolls refer to the player, not the character, being passive (in the sense that they are not rolling dice). Actively turning a place over searching for secret doors repeatedly is given as an example of a passive roll. It’s like 5e’s version of “take 10.”

Also there’s a section in the DMG (off on its own, in some random place, easily missed… like so many of 5e’s skill rules) defining the difference — like you surmise Investigation is making deductions and putting information together, while perception is for seeing things.

So for example, you see an illusion plainly — there’s no perception check needed there. But an investigation check (possibly a passive one) might be needed to realize that something is off in what you see.

[stoutstien]

Also there’s a section in the DMG (off on its own, in some random place, easily missed… like so many of 5e’s skill rules) defining the difference —

Should get this printed on Tshirts and give them out when one purchases DMs.

[Maan]

Also there’s a section in the DMG (off on its own, in some random place, easily missed… like so many of 5e’s skill rules) defining the difference — like you surmise Investigation is making deductions and putting information together, while perception is for seeing things.

It's even worse than that: many published adventures ask for Perception (passive or check) when searching for something. Really looks like developers themselves were confused about it.
Also, I have this feeling that Investigation was added when someone said "ehy, don't Wizards need to be good at this kind of stuff, too?" :smallbiggrin:

[MoiMagnus]

Also, I have this feeling that Investigation was added when someone said "ehy, don't Wizards need to be good at this kind of stuff, too?" :smallbiggrin:

I have a better theory: "Eh, we used the Intelligence save to disbelieve Illusion spells, but wouldn't that make more sense if that was a skill check rather than a saving throw?"

[Tanarii]

Search and Spot used to be different skills, the first Int and second Wis. The designers sat down and thought "let's change the skill names and make them a little broader" ... and in the process screwed up a clear understanding of which is for which.

Now everyone and their mother thinks than any kind of searching is Perception, along with spotting.

Yes, there is some overlap. Mainly when you're visually searching an area for something hard to spot. That could be either, and always could be even in 3e days. I usually run that as Investigation if it's close by (more likely to be mentally analyzing in detail) or Perception if it's far (more likely to be visually scanning).

In other words, trap finding Rogues IMC generally need high Passive Investigation, and Rangers scouting for the enemy generally need high Passive Perception.

Creatures are more hearing to find anyway. Perception is definitely the default 'Listen' or 'Hear Noise' skill. Another thing they did of course being combining Spot and Listen into a single Wis skill.

[Slipjig]

When would passive investigation even come into play?

That's kind of my dilemma. I took Observant for a high-Int, low-Wis character, and my Passive Investigation is now a 20. But if Passive Investigation is never going to come up, that's kind of a waste of a feat since his Passive Perception is still one of the lower ones in the group at 14.

[Tanarii]

That's kind of my dilemma. I took Observant for a high-Int, low-Wis character, and my Passive Investigation is now a 20. But if Passive Investigation is never going to come up, that's kind of a waste of a feat since his Passive Perception is still one of the lower ones in the group at 14.
Passive investigation should apply whenever you're 'actively' Investigating repeatedly, ie as you move along checking if there's traps or secret doors. Passive perception also applies then of course, so it depends if you figure out where a trap/secret door could be, or spot a telltale sign. Or you might need both. Ask your DM.

[KorvinStarmast]

“Passive” rolls refer to the player, not the character, being passive (in the sense that they are not rolling dice).
Also there’s a section in the DMG (off on its own, in some random place, easily missed… like so many of 5e’s skill rules) defining the difference — like you surmise Investigation is making deductions and putting information together, while perception is for seeing things.

So for example, you see an illusion plainly — there’s no perception check needed there. But an investigation check (possibly a passive one) might be needed to realize that something is off in what you see. Good summary.

It's even worse than that: many published adventures ask for Perception (passive or check) when searching for something. Really looks like developers themselves were confused about it. Fair enough.

Passive investigation should apply whenever you're 'actively' Investigating repeatedly, ie as you move along checking if there's traps or secret doors. Passive perception also applies then of course, so it depends if you figure out where a trap/secret door could be, or spot a telltale sign. Or you might need both. Ask your DM. That also.

[Keravath]

As mentioned - and worth repeating - PASSIVE has nothing to do with the character - it has to do with the player not rolling dice.

1) A character walking along doing something other than paying attention to their surroundings doesn't even have a passive perception (see the detecting threats while traveling rules). The character must be taking an appropriate action in order for any skill, passive or active to apply. (However, even some of the published rules get confused on this point).

2) In the PHB, passive skills are for times when the DM wants to determine information to give the players without having them roll dice giving away that there is something to be found. It is also for situations where a task is done repeatedly - like searching for secret doors. It is inconvenient to have everyone roll dice every 10' of corridor just to see if they notice something.

Finally, investigation and perception can both be used to find things. Here is how I understand the difference.

Perception - has to do with the senses and noticing details. Sight, sound, smell. Noticing a slight movement in the air, a smell of dust when there doesn't appear to be any dust nearby, a slight graze on the floor near a wall. Anything that could be difficult to notice falls into the category of perception.

For example, if a secret door is well hidden but figuring out how to open it isn't that hard once you know it is there - that would be a perception check.

Investigation - has to do with reasoning and logic. Dealing with clues and figuring out what your senses are telling you. Sometimes the details are fairly easy to spot if you are looking for them - eg the fact that a drawer is slightly more shallow than its neighbour - but then deducing that this means there could be a secret compartment is where investigation comes into play. Alternatively, a hidden door that is fairly easy to see but difficult to figure out how to open would be an investigation check.

Thus searching a room for a hidden door could involve perception, investigation or even both for a well hidden door with a difficult to figure out mechanism to operate it. It is up to the DM. (I think it usually defaults to perception for finding hidden doors since someone wants to use the door without too much trouble - so they hide it well but the mechanism to open it can either be noticed when you find the door or isn't that hard to find).

Finding traps could similarly be perception, investigation or both at DM discretion.

In general, noticing something is perception, figuring it out is investigation.

[Kurt Kurageous]

When would passive investigation even come into play?

Perception to see secret door. Investigation to figure out it's a trap/false door.

Passive perception is told what they see, passive investigation is told what they know.