D&D 5E (2014) Perception vs Investigate

[DEFCON 1]

That's dangerous though because the player is operating on an assumption, however well-founded. It's always helpful in my view to try to verify that assumption before acting on it.

Well, sure... but I just don't demarcate Investigation as the skill to use for it. Or at least, that being the only use of the skill. As I said, I felt Investigation needed more heft and Perception needed to be brought down to earth, which is why I did the living/inanimate split on the two skills.

 

[iserith]

Well, sure... but I just don't demarcate Investigation as the skill to use for it. Or at least, that being the only use of the skill. As I said, I felt Investigation needed more heft and Perception needed to be brought down to earth, which is why I did the living/inanimate split on the two skills.

It makes sense to me that, if the player thinks Colonel Mustard is the killer based on the lead pipe encrusted with dried blood and hair found in the conservatory, that a fictional action declaration of "I try to deduce whether Colonel Mustard is the culprit based on the clues I've found thus far..." would call for an Intelligence (Investigation) check if the result of that action was deemed uncertain by the DM. What would you use instead? Just a straight Intelligence check perhaps?

 

[DEFCON 1]

It makes sense to me that, if the player thinks Colonel Mustard is the killer based on the lead pipe encrusted with dried blood and hair found in the conservatory, that a fictional action declaration of "I try to deduce whether Colonel Mustard is the culprit based on the clues I've found thus far..." would call for an Intelligence (Investigation) check if the result of that action was deemed uncertain by the DM. What would you use instead? Just a straight Intelligence check perhaps?

No, something like that would probably be INT (Investigation)... but truth be told my players probably wouldn't ask for checks for it and I wouldn't give a Yea or Nea after the fact. Rather, they'd just make their deductions and then take the RP from there. In many ways that kind of stuff we'd treat more like puzzles... not something you get to bypass with just a check. Instead, you do the figuring on your own and then act based upon what you've come up with. But that's just our table.

 

[iserith]

No, something like that would probably be INT (Investigation)... but truth be told my players probably wouldn't ask for checks for it and I wouldn't give a Yea or Nea after the fact. Rather, they'd just make their deductions and then take the RP from there. In many ways that kind of stuff we'd treat more like puzzles... not something you get to bypass with just a check. Instead, you do the figuring on your own and then act based upon what you've come up with. But that's just our table.

For me, you do the figuring on your own and then you may have the option to double check your findings by making a deduction based on the clues. Like any other action, the result may be successful (overwhelming evidence, obvious answer, etc.), unsuccessful (scant evidence or too many possibilities), or have an uncertain outcome (somewhere in between) at which point I would call for that Intelligence (Investigation) check. Confirming one's theory about something is never the end of the story - indeed it's just the beginning of the next phase of play where you act on that deduction - so I think it's fine to let the character's Intelligence come into play under the right fictional circumstances.

 

[marcelvdpol]

One way to use int (investigation) is if a player is stating his character is actively searching for traps using the classic 11-foot pole.

Albert einstein (investigation) vs Robin Hood (perception) is a good comparison. Unfortunately the bbc sherlock is very good at both perception (noticing small details like scratches on a watch, small tremors of the hand etc) as well as investigation (deducing the meaning of those details). It would make a very cool character though (most likely a rogue and/or bard due to the ease at which he learns additional skills with a city guard or criminal background) with both high intelligence as well as wisdom.

 

[Jackdaw]

I've been using "the animal test" to distinguish Perception and Investigation, since may animals have a good Perception but usually a low/negative Investigation.

If an animal could usefully react to the information (immediate threats, tracking, signs of struggle that mark the area as potentially dangerous, crude hunting traps and pits, etc.) = Player rolls Perception

If an animal couldn't usefully react to the information (unusual craftsmanship, tattoos, fingerprints, out of place items, ciphers, complex/engineered traps and secret doors, etc.) = Player rolls Investigation

It's not black and white: there's still wiggle room but it's usually the first layer of consideration.

 

[TheCosmicKid]

I've been using "the animal test" to distinguish Perception and Investigation, since may animals have a good Perception but usually a low/negative Investigation.

Like all strokes of genius, obvious in hindsight. Great idea.

 

[Sir Brennen]

I pretty much run things along the lines the majority of posters have stated:

Perception - active or passive check of the senses to notice something, usually pretty immediate, binary (pass/fail) result.
Investigation - active search to piece together information, usually requires some time spent to accomplish (anywhere from a round to possibly hours or days), and may have a binary or degree of success result.

The "animal test" is a great idea, BTW.

Here's one thing I have a problem with: the Observant Feat. Specifically, the part that gives a +5 on passive Intelligence (Investigation) checks.

What the heck is a passive Investigation check? Because to me, Investigation is an activity, it can't really be passive. It's like getting a bonus for a passive jump check.

I had a player take this feat and such a check never came up; even the player wasn't sure under what circumstances it would. I'm tempted to try and figure out some other benefit to replace the bonus with.

I suppose if the DM is making rolls for a trap vs player Int (Investigation) rather than have the player make the roll, but that's more of a variant and shouldn't be a feature in a feat.

 

[robus]

What the heck is a passive Investigation check? Because to me, Investigation is an activity, it can't really be passive. It's like getting a bonus for a passive jump check.

A passive check is for repeated activity, not subconscious activity. So yes, if you were "bouldering" down a hill a passive athletics check might be appropriate. PCs that fail fall and take some bludgeoning damage. Or would you prefer to make athletics checks for each boulder?

As far as investigation goes, a passive check would cover spending time in a research library (for example). A passive check success would have the PC find what they're looking for in a hour say, a failure would take all day.

 

[iserith]

I pretty much run things along the lines the majority of posters have stated:

Perception - active or passive check of the senses to notice something, usually pretty immediate, binary (pass/fail) result.
Investigation - active search to piece together information, usually requires some time spent to accomplish (anywhere from a round to possibly hours or days), and may have a binary or degree of success result.

The "animal test" is a great idea, BTW.

Here's one thing I have a problem with: the Observant Feat. Specifically, the part that gives a +5 on passive Intelligence (Investigation) checks.

What the heck is a passive Investigation check? Because to me, Investigation is an activity, it can't really be passive. It's like getting a bonus for a passive jump check.

I had a player take this feat and such a check never came up; even the player wasn't sure under what circumstances it would. I'm tempted to try and figure out some other benefit to replace the bonus with.

I suppose if the DM is making rolls for a trap vs player Int (Investigation) rather than have the player make the roll, but that's more of a variant and shouldn't be a feature in a feat.

A passive check is for repeated activity, not subconscious activity. So yes, if you were "bouldering" down a hill a passive athletics check might be appropriate. PCs that fail fall and take some bludgeoning damage. Or would you prefer to make athletics checks for each boulder?

As far as investigation goes, a passive check would cover spending time in a research library (for example). A passive check success would have the PC find what they're looking for in a hour say, a failure would take all day.

^This. When you stop thinking of "passive" as not actively doing a thing and recognize that it just means there is no rolling involved, then everything about passive checks begins to make sense in my experience.

One thing I do is that, when adventuring, I make sure I am checking with the players on what their characters are "generally" doing, reminding them that if they are doing anything that could potentially distract from keeping watch for danger, then they have no chance to avoid surprise, if it comes up (unless the character is a ranger). Anytime the outcome of the task they are generally doing requires resolution with a game mechanic, then it goes to the passive version. I have found that when you make it a point to have each player establish the general tasks they are doing unless they state otherwise, it makes it very easy for the DM to adjudicate. It also helps when there's a benefit to doing a general task other than keeping watch for danger so that it's an interesting choice for the player to make. Drawing a map isn't all that attractive a general task when you're sure to be surprised if a monster is sneaking up on you - but make that map worth gold back in town and suddenly it's an interesting calculation for the player to make.