The descriptions of these skills in the Player's Handbook are:
Investigation: Find obscure information in books, or deduce how something works.
Perception: Using a combination of senses, notice something that's easy to miss.
Based on that, the official word is that Perception would be the skill to use for actively searching for traps.
However, some DMs prefer to call for Investigation checks when someone is actively searching for something and use Perception as more of a reactive check to see if you notice something that's happening or about to happen.
The descriptions of these skills in the Player's Handbook are:
Investigation: Find obscure information in books, or deduce how something works.
Perception: Using a combination of senses, notice something that's easy to miss.
Based on that, the official word is that Perception would be the skill to use for actively searching for traps.
However, some DMs prefer to call for Investigation checks when someone is actively searching for something and use Perception as more of a reactive check to see if you notice something that's happening or about to happen.
DMs misuse the investigation check on that way all the time. But it creates this weird situation where most players are better off not actively searching because they have a -1 where if they just casually look around they have +25. It’s awkward. It should be easier to actively search for something than it is to casually look around. For this reason I’d recommend only using perception. It also makes players feel penalized because the dm is asking for their weaker skill instead of smart to look for something.
The current DMG offers advice on when to use which here.
I like that advice. It's also the way I've been doing it in our games. Let me put the part I found interesting here:
Using the Investigation Skill. The Investigation skill applies to situations where a character is using reason and deduction to arrive at a conclusion about something under examination. Investigation applies when characters are trying to figure out how a thing works—how to open a trick door, how to get into a secret compartment, and so on.
Don’t use the Investigation skill to determine if a character notices something—that’s the purview of Perception. For example, a successful Wisdom (Perception) check allows a character to find a secret door or something that betrays its presence, such as thin seams marking the edges of the door. If the secret door is locked, a successful Intelligence (Investigation) check would allow a character to figure out the trick to opening it—by turning a nearby statue so it faces the door, for example.
Also, for the OP, here are some threads I find interesting about this topic:
Perception if the character is just using their eyes, investigation if they are using their hands.
Perception to notice something is amiss: maybe a wire or a spiderweb, a gap in the floor, a slight breeze, a different color, worn section, less dust in places, a creak,
If a character is actively searching for a trap or trap door, or something, I think investigation works. Is the gap in the floor significant, or is it just a gap in the floor. Perception noticed something odd, but investigation determines whether it is a trip wire or just a spiderweb.
But this is where I think secret rolls should come into play.
Players roll and then see their result and then usually act accordingly. When I am searching for traps, I roll for the DM, and don't look at my result. That way if I roll badly, the DM has the possibility of setting me up for a false positive. I like the tension and verisimilitude when my roll is unknown but the DM states, "You are positive there is no trap." Maybe I rolled a 20 on my investigation, maybe I rolled a 20. Either way, I am going to act like there is no trap.
In conclusion, I feel the DM and player navigate whether to use perception or investigation. Is the character just noticing or trying to figure something out.
Though it may not be exactly RAW, at our table Perception is used for things that you would see or hear immediately. Investigation is for things you are actively searching for.
Basically we use a "10 second rule".
"I look around the room to see if I spot any obvious traps." - Roll Perception
"I very carefully check the large scary door in front of us for traps." - Roll Investigation
Though it may not be exactly RAW, at our table Perception is used for things that you would see or hear immediately. Investigation is for things you are actively searching for.
Basically we use a "10 second rule".
"I look around the room to see if I spot any obvious traps." - Roll Perception
"I very carefully check the large scary door in front of us for traps." - Roll Investigation
This is pretty much how I've always done it, and even if it's not RAW, it seems to be what most players expect or find intuitive.
So I should use perception to see if there is a trap, and Investigation to find out what kind of trap?
Well, in the 2024 DMG, not all traps have the same Detect and Disarm behavior. I mean, not always a Wisdom (Perception) check and then an Intelligence (Investigation) check.
For example:
Collapsing Roof uses a Search action and a Wisdom (Perception) check to examine the trapped area. Once detected, the trip wire can be easily cut or avoided (no ability check required).
Poisoned Needle also uses a Search action and a Wisdom (Perception) check to examine the trapped lock. Once the trap is detected, a character can take an action to try to disarm the trap making a Dexterity (Sleight of Hand) check.
Spiked Pit uses a Study action and an Intelligence (Investigation) check, detecting the pit on a successful check. Once the hidden pit is detected, an Iron Spike or a similar object can be wedged between the pit’s lid and the surrounding floor to prevent the lid from opening, thereby making it safe to cross.
The 2014 DMG had this general advice:
A trap’s description specifies the checks and DCs needed to detect it, disable it, or both. A character actively looking for a trap can attempt a Wisdom (Perception) check against the trap’s DC. You can also compare the DC to detect the trap with each character’s passive Wisdom (Perception) score to determine whether anyone in the party notices the trap in passing. If the adventurers detect a trap before triggering it, they might be able to disarm it, either permanently or long enough to move past it. You might call for an Intelligence (Investigation) check for a character to deduce what needs to be done, followed by a Dexterity check using thieves’ tools to perform the necessary sabotage.
For simplicity I always associate Investigation with 3E Search and Perception with 3E Spot. It becomes a lot easier to decide which skill to use. Therefore, as DM I always use Investigation when a PC wants to search for traps, search for secret doors, etc. The players know this of course at character creation should searching for stuff be important to them.
What skill is used in finding traps? I hear investigation, but I think it's Perception. What do you guys think?
Both:
Perception reveals that something is off. Investigation reveals what the trap is.
The descriptions of these skills in the Player's Handbook are:
Investigation: Find obscure information in books, or deduce how something works.
Perception: Using a combination of senses, notice something that's easy to miss.
Based on that, the official word is that Perception would be the skill to use for actively searching for traps.
However, some DMs prefer to call for Investigation checks when someone is actively searching for something and use Perception as more of a reactive check to see if you notice something that's happening or about to happen.
pronouns: he/she/they
The current DMG offers advice on when to use which here.
Perception. Is the correct skill
investigation would be to reason with how to deactivate the trap.
Basically perception is for noticing things. Investigation is for using logic and reason about things.
DMs misuse the investigation check on that way all the time. But it creates this weird situation where most players are better off not actively searching because they have a -1 where if they just casually look around they have +25. It’s awkward. It should be easier to actively search for something than it is to casually look around. For this reason I’d recommend only using perception. It also makes players feel penalized because the dm is asking for their weaker skill instead of smart to look for something.
I like that advice. It's also the way I've been doing it in our games. Let me put the part I found interesting here:
Also, for the OP, here are some threads I find interesting about this topic:
So I should use perception to see if there is a trap, and Investigation to find out what kind of trap?
Perception if the character is just using their eyes, investigation if they are using their hands.
Perception to notice something is amiss: maybe a wire or a spiderweb, a gap in the floor, a slight breeze, a different color, worn section, less dust in places, a creak,
If a character is actively searching for a trap or trap door, or something, I think investigation works. Is the gap in the floor significant, or is it just a gap in the floor. Perception noticed something odd, but investigation determines whether it is a trip wire or just a spiderweb.
But this is where I think secret rolls should come into play.
Players roll and then see their result and then usually act accordingly. When I am searching for traps, I roll for the DM, and don't look at my result. That way if I roll badly, the DM has the possibility of setting me up for a false positive. I like the tension and verisimilitude when my roll is unknown but the DM states, "You are positive there is no trap." Maybe I rolled a 20 on my investigation, maybe I rolled a 20. Either way, I am going to act like there is no trap.
In conclusion, I feel the DM and player navigate whether to use perception or investigation. Is the character just noticing or trying to figure something out.
Though it may not be exactly RAW, at our table Perception is used for things that you would see or hear immediately. Investigation is for things you are actively searching for.
Basically we use a "10 second rule".
"I look around the room to see if I spot any obvious traps." - Roll Perception
"I very carefully check the large scary door in front of us for traps." - Roll Investigation
This is pretty much how I've always done it, and even if it's not RAW, it seems to be what most players expect or find intuitive.
pronouns: he/she/they
Well, in the 2024 DMG, not all traps have the same Detect and Disarm behavior. I mean, not always a Wisdom (Perception) check and then an Intelligence (Investigation) check.
For example:
The 2014 DMG had this general advice:
For simplicity I always associate Investigation with 3E Search and Perception with 3E Spot. It becomes a lot easier to decide which skill to use. Therefore, as DM I always use Investigation when a PC wants to search for traps, search for secret doors, etc. The players know this of course at character creation should searching for stuff be important to them.
We roll twice.
Perception tells you something is off, IF there is something to perceive.
Investigation to find out what the trap is and if/how it can be disarmed once it has been perceived.
A well-fitted solid door that opens inward against a lever could not be perceived nor disarmed from the outside.
At least that's how we do it.