D&D 5E Investigation vs Perception

[Jester David]

Robin Hood versus Sherlock Holmes. Daredevil versus Batman.

Is the issue if something can be physically seen? Is the strength of the senses at play? Perception.
Spotting a tiny object, seeing far in the distance, hearing a distant sound, detecting a very faint odor, etc.

Is the issue noticing details that are visible or not obscured? Is it piecing together clues? Investigation.
Noticing the footprints in the dust all step over the same square, or the scratch marks on the floor, identifying the scent in the air, etc.

If a tool could help you succeed (magnifying glass, ear trumpet) then Perception. If time and talking could help you succeed then Investigation.

They're not mutually exclusive. There's overlap, like with Acrobatics and Athletics.

 

[Li Shenron]

I think I've been a bit too carefree with Int/Wis checks and their skill bonuses so far...

I'd like to put more structure into their use. For example one possible alternative that I'd like to try out could be:

- Int/Investigation to find what you are looking for
- Wis/Perception to find what you are not looking for

but then also adding that you cannot find something purposefully hidden unless you're looking for it; if you are not looking for it, Wis/Perception might let you notice you a clue, but then Int/Investigation to complete the discovery.

Examples:

- Trap, hidden door, hidden object: you can find them if you declare you are searching for them (Investigation), you won't find them with Perception alone; but if you don't search for them, perception (passive or not, DM's call) might let you notice that a tile on the floor is different, or that there are faint footsteps ending up against a wall

- Hiding creature: if you know it's somewhere (perhaps because previously you could see it) then you just declare you search for it (Investigation), if you have no reason to search for it then you may be granted a Perception check to notice a rustling noise in the foliage or recently displaced sand or dirt

- Ambush: this is a special case of hiding creatures normally ending with an attack; a Perception check at the last instant can still save you from being surprised, but it might be ruled that to foil an ambush well in advance (for example understanding the number, positions and nature of the ambushers) requires to be actively looking for signs of it with Investigation

- Casually hidden object: maybe someone accidentally dropped a key in the grass... if it's not purposefully hidden (or if it was hidden lousily) then it's fair to have a chance to find it equally accidentally, but the difference may be in higher DC for Perception compared to Investigation

 

[Rya.Reisender]

Yeah that usually works quite well.

I usually don't have problems in deciding whether something is perception or investigation. Just describing it to someone else what the difference is, is harder for me.
"I want to look around and see if there's anything suspicious in this room." -> Perception
"I want to figure out what the room was used for." -> Investigation

 

[Plaguescarred]

FWIW Jeremy Crawford offered a good rule of thumb on twitter http://www.sageadvice.eu/2015/04/08/perception-and-investigation/


@JeremyECrawford Rule of thumb: Use Perception to spot/hear something. Use Investigation to deduce something based on clues. There can be overlap.

 

[77IM]

For searching, I allow either skill.

I'm a huge fan of overlapping skills. It speeds up the game because you don't have to think as hard about which skill is most appropriate; it increases chance of success which tends to move the game along more quickly; it encourages more PCs to take action; and it reinforces character concepts without as many mechanical penalties.

Of course no two skills overlap completely. In this case, I exclusively use Perception for reactive checks (like spotting an ambush or hearing a loud but distant sound) and I exclusively use Investigation for research and for interpreting clues.

 

[guachi]

I'd like to put more structure into their use. For example one possible alternative that I'd like to try out could be:

- Int/Investigation to find what you are looking for
- Wis/Perception to find what you are not looking for

This is a good summary of what I do. Intelligence is an underused ability so I'm happy to give it things that might otherwise be perception checks.

My current game I've got a melee rogue who dumped Constitution (really!) to boost Intelligence. He's basically turned into the "I search the room" guy and I'm happy to let him use Investigation when he's actively searching.

Though I do attempt to use perception for characters to notice hidden living things or when they are searching for a clue without knowing its significance.

EDIT: A big reason I don't use Investigation to deduce clues and figure stuff out is I have yet to encounter players who haven't been able to figure stuff out on their. Sometimes I've needed to give them another clue (either with or without a perception check) or start them on the first step of a logical deduction, but I have yet to need more than a nudge.

 

[Horwath]

I really do not like the investigation skill. It is mostly replaced in 90% of rolls by perception.

It is for players: I do not want to think about this riddle problem, so I'll roll it and maybe get lucky.

I.E; perception, you found a secret door. but you don't know how it opens. So what now. Roll investigation? AAAAAA!!

No!

Maybe some player thinks; maybe there is some hidded pressure plate? OK, all roll perception to notice a pressure plate? Nothing.

Maybe it's not that, or maybe we cant find it.

Someone else says; maybe there are tiny holes in floor to pour water in it to fill some mechanisam. All roll perception.

You found 3 1mm wide holes on the floor under the dust that you think are for that reason. You pour some water into them.

Door opens. Yay! all dex save; your first perception wasn't high enough to spot the trap on the secret door.


Basically delete investigation and let players think for themselves.

 

[iserith]

You found 3 1mm wide holes on the floor under the dust that you think are for that reason.

Basically delete investigation and let players think for themselves.

Hmm...

 

[iserith]

EDIT: A big reason I don't use Investigation to deduce clues and figure stuff out is I have yet to encounter players who haven't been able to figure stuff out on their. Sometimes I've needed to give them another clue (either with or without a perception check) or start them on the first step of a logical deduction, but I have yet to need more than a nudge.

In my experience, it's more about confirming theories and assumptions. The players think NPC X is the murderer based on what they know, but want to have their character make a deduction that either confirms or refutes that. An Intelligence (Investigation) check may follow if the evidence found may or may not conclusively point to NPC X being the murderer (or not the murderer).

 

[Caliban]

I know at least one DM who uses Investigate as a "hands on search" and Perception as a "visual only" search. So there are traps that cannot be found with Perception because they are not visible, but you can find them with Investigate via feeling around and poking and prodding with your thieves tools. Like a pressure plate or a poison needle trap inside a lock.

I don't necessarily agree, because Investigate says nothing about that, but it seems to work for him.