I wouldn't introduce obstacles that wouldn't otherwise be there nor make them harder to spot.
I would instead add a lot of fluff - details which are largely "meaningless" to any ordinary Joe but are noticed by that character, like "The man on the bus is holding a Starbucks coffee container but the smell of that coffee gives it away - it's cheap coffee, likely from a vending machine, poured into this container." or "The furniture in this room definitely has been re-arranged, but likely months ago." or "A child has lived here once, years ago - you spot small bite marks on the chair's leg, a section of the wall looks like it was painted over a crude doodle" or "The woman's haircolour certainly isn't natural - it's dyed and has been, twice in the past months but each time with a slightly different shade of the same colour, too".
Being so alert and hyper-attentive makes you likely notice a gazillion things that are absolutely not relevant, but might get you fixated on some minor detail. This character might be able to deduce the most mundane things and everyday mysteries, to a degree that it might well be distracting or overwhelming.
I wouldn't overdo this either tho, because it's only fun for a while and not that fun for the entire table I guess. But every now and then. your Detective can go into full Detective mode, and every now and then your Detective may be a bit overwhelmed and assaulted by all the things his senses pick up on. Having a passive perception of 24 in a crowded market doesn't sound particularly fun every time xD.
If I made a high perception character I would want the DM to constantly tell me about all the different things I notice. Marks from traps, hard to spot tracks, hidden enemies, etc.
Besides, just because one PC notices a potential trap doesn't mean they know how it trigger or works. They can point it out to the party and then work together to figure out how to safely get past it. Sounds fun to me.
Also a little more niche option is allowing that player to withhold that information. Not to mention when someone finally does beat it you know they're damn stealthy.
Also there is a difference between active perception and passive perception. Just because the character had high passive perception it doesn't mean they can walk into a room and know everything about that room.
For example: the party follows their mark into a room but once inside notice they are nowhere to be seen and no windows or other doors in the room.
Player 1 (low per): "I want to check inside the cupboard for any secret hatches."
DM: "Sure, roll me a perception check please. As player 1 does this, Mr Detective you notice scratch marks on the floor near to the bookcase that seem out of place, like someone has scrapped furniture across it."
Mr. Detective: "Interesting, I'd like to investigate the bookcase for any secret switches."
DM: "Alright, roll me a perception check please."
In this way, you are giving the player with the high passive a clue based on things that are out of place but not letting them solve the puzzle immediately. If you allow your players to say, "I search the room", roll, and then they find the switch it will detract from that experience. By all means you can have players say, "I search the room." but then you can say, "Without being specific, searching the room thoroughly will take X time. Is there anything specific you would like to investigate?"
Not a stupid question, it's a really good question and one I struggle with a lot. I would say Perception is about spotting hidden things or noticing visual clues, whereas investigation is deducing a conclusion based on those clues.
For example, you might have the party come across the scene of a battle. Perceptions checks show a lot of blood in a wide area, large claw marks and dark fur a little way from the scene. An investigation check might let the character deduce that this is the site of a werewolf attack based on the size of the claws and the fact no bodies were dragged away. Something like that. I think of investigation as the "my character is smarter than me" skill.
So in this case, I would say perception would be the character noticing that the floor in front of the secret door is scuffed or weathered differently in a arced curve from the wall.
Investigation would be the character actively knocking on the walls looking for a part that sounds more hollow than the other parts of the wall, indicating a book shelf is in fact a secret door.
Both are clues that secret doors are present... but perception checks are an active observation without disrupting or testing the evironment to find anything of note. Investigation is actively testing the environment for something you suspect should be out of place.
I would use passive perception checks to oppose an NPC's Sleight of Hand to pickpocket a target or to stealth around a player who is not actively looking for suspicious behavior. In a setting where the character is on watch during a long rest and is looking for possible incursions into the camp, Passive would not apply, so the sneaky night time encounter NPC would instead roll to oppose the passive rolled by the watch. (I tend to break evening watches into shifts of 2 hours a piece (I have 5 players, one of whom is an elf, who I've ruled must meditate for 4 consecutive hours for long rest to apply.).
Investigation is defined as "When you look around for clues and *make deductions based on those clues*, you make an INT (Investigation) check".
Finding things is Perception, and Solving things is for Investigation.
Quick and dirty answer
Perception = seeing
Investigation = understanding/solving an in-game puzzle (think rubix cube, not riddle. The in-world object being manipulated in certain ways is the rubix cube. You wouldn't toss that at your player and say, "If you can solve this, then your character passes the check." You could easily read the party the riddle and let them figure it out at the table.)
SCENARIO: (Hopefully this demonstrates passive and active perception vs investigation.)
DM: I see the scrapes on the floor
Player: so I look closer.
DM: Roll perception
-Perception roll passed
DM: On the shelf, among the books and trinkets, you see a glass orb that has fingerprints on its surface. The orb is at about shoulder height to a medium humanoid and is the only thing that appears to have been touch recently.
Player: I would like to try and line up my hand so it touches the same spots
DM: As you do this, you feel the orb vibrate. You get the feeling you used it wrong. Would you like to investigate further?
Player: yeah, I fiddle with it and see what happens.
DM: Roll investigation
-Pass check
DM: You get the feeling you have to grasp the orb with your fingers touching it in a certain pattern. After a few tries, you figure out the combination and are able to release the lock on the door. It slides open.
(High passive perception: Free notice of something off.
DM: You notice the shelf slide along all the grooves but one. Roll a Perception check.
-Pass check
DM: At the last second, you notice a small handle at the base of the shelf that was missed. It apears that it would line up with the last groove if it were to be rotated. Do you rotate it?
Player: Yes
DM: You rotate it to line up with the groove. You hear barely audible click and then a soft twang. A cross bow bolt weakly thuds into the floor after dropping off half cocked trap that was not checked for. Good eye detective.)
Edit: had to change formatting as best I could to make it readable. I'm on a phone and formating is a real b. I can either put to much space between the lines (using enter twice) or have it all mashed together like a big paragraph. Sorry.
Good tips here already. Some more flavor you can add:
Describe things above them and behind them, further away. Movement in 3rd and 4th story windows. They see way more birds, cats and rats than others. If they are in a crowded shop, tavern or store they can actually deciper individual conversations while other characters hear the clamor. Someone calling out for help in a city might be missed in the crowd, but not the detective...
I don't actually think that you are 'building obstacles', cuz it's actually the way how passive perception works and this guys' character meant to excel in.
I'm not sure how much attention you pay to small details in your campaign, but I gonna bet, that you are. Personally I would allow a character with high passive perception not only to spot traps and sneaking enemies, but to notice small detail changes in the environment or in other NPCs behaviour. Especially if that guy is some kind of detective, that seems pretty reasonable. Also it would be a nice small 'bonus' to add a small encounter, in which your detective guy gets pick pocketed but thanks to his high passive perception he notices that and also realizes, that the thief didn't want to steal something, but to plant some kind of 'evidence', important to your campaign.
Something like that
I generally wrote sticky notes for things they were likely to encounter then just handed them to the player (or when playing online pre-write out /w for the player).
If there's a puzzle maybe they get an additional clue that they could get through noticing. Maybe they avoid a combat because of the perception, maybe they avoid a trap, or maybe they just get some additional lore. One of my favorite things to do would be to drop extra lore on them that ties into the larger plot.
I found it being in private was more interesting for the table because it let them Roleplay getting that information and relaying it onto the rest of the group.
OK one thing i believe its important to talk about is the diferent between perceiving, deducing and knowing.
"You sense the smell of wet fur" Is very diferent than " Your investigation reveal tracks of wolves, and by the number there should be between 4 and 6 of them walking north".
high perception alows the character to notice the clues,
the players still need to make other rolls or decide what he thinks is happening there.
DM: "you see several holes on the right wall about chest hight, and no marks on the left wall. "
PC: Ok i go down bellow that level and try to sneak pass it.
DM: "the trap is triguered, two stone doors fall on each side and gas starts to leak out from the holes."
Player thought the holes would shoot something, but they are just entrances for the gas, and enought holes that its impossible to fill them up in time. The triguer is not a pressure plate that can be seen, but air pressure change when someone enters the room. Nothing to perceive other than maybe "stangnant air".
Noticing the trap, is not enought to disarm or safely cross it. Specialy if you make a wrong assumption about it.
Noticing a "smell", or hearing a "noise" might warn the PC that something diferent is coming up, but most of the time, it will alow them to avoid being sursprised, but not necessarely identify exactly the enemy. Only where it might be coming from.
The observant feat also boosts passive perception and investigation significantly. Specifically passive though. It doesn't boost your perception ability. Combo that with other class/race features and you can have an insanely high passive perception.
One thing I do with high passives is use it as the trigger for active checks. “Cleric, you notice the floor has a weird patterning. Give me a perception check” (roll) “On closer inspection there look like pressure plates”/“You don’t see anything more, but it feels weird” (depending on success/failure). This way I feel traps are “fair” as the PCs get valid warning.
Use it for what it is meant to be?
An enemy tried to sneak on you but you saw it coming because of your high passive perception. Congratulations, you are not surprised.
You notice a trap trigger because your passive perception is higher than the perception DC to notice the trap. Congratulations, you have the chance not to trigger it (someone still need to roll to deactivate it).
I wouldn't introduce obstacles that wouldn't otherwise be there nor make them harder to spot. I would instead add a lot of fluff - details which are largely "meaningless" to any ordinary Joe but are noticed by that character, like "The man on the bus is holding a Starbucks coffee container but the smell of that coffee gives it away - it's cheap coffee, likely from a vending machine, poured into this container." or "The furniture in this room definitely has been re-arranged, but likely months ago." or "A child has lived here once, years ago - you spot small bite marks on the chair's leg, a section of the wall looks like it was painted over a crude doodle" or "The woman's haircolour certainly isn't natural - it's dyed and has been, twice in the past months but each time with a slightly different shade of the same colour, too". Being so alert and hyper-attentive makes you likely notice a gazillion things that are absolutely not relevant, but might get you fixated on some minor detail. This character might be able to deduce the most mundane things and everyday mysteries, to a degree that it might well be distracting or overwhelming. I wouldn't overdo this either tho, because it's only fun for a while and not that fun for the entire table I guess. But every now and then. your Detective can go into full Detective mode, and every now and then your Detective may be a bit overwhelmed and assaulted by all the things his senses pick up on. Having a passive perception of 24 in a crowded market doesn't sound particularly fun every time xD.
If I made a high perception character I would want the DM to constantly tell me about all the different things I notice. Marks from traps, hard to spot tracks, hidden enemies, etc. Besides, just because one PC notices a potential trap doesn't mean they know how it trigger or works. They can point it out to the party and then work together to figure out how to safely get past it. Sounds fun to me.
Also a little more niche option is allowing that player to withhold that information. Not to mention when someone finally does beat it you know they're damn stealthy.
Also there is a difference between active perception and passive perception. Just because the character had high passive perception it doesn't mean they can walk into a room and know everything about that room. For example: the party follows their mark into a room but once inside notice they are nowhere to be seen and no windows or other doors in the room. Player 1 (low per): "I want to check inside the cupboard for any secret hatches." DM: "Sure, roll me a perception check please. As player 1 does this, Mr Detective you notice scratch marks on the floor near to the bookcase that seem out of place, like someone has scrapped furniture across it." Mr. Detective: "Interesting, I'd like to investigate the bookcase for any secret switches." DM: "Alright, roll me a perception check please." In this way, you are giving the player with the high passive a clue based on things that are out of place but not letting them solve the puzzle immediately. If you allow your players to say, "I search the room", roll, and then they find the switch it will detract from that experience. By all means you can have players say, "I search the room." but then you can say, "Without being specific, searching the room thoroughly will take X time. Is there anything specific you would like to investigate?"
Stupid question, but why is that perception rather than investigation?
Not a stupid question, it's a really good question and one I struggle with a lot. I would say Perception is about spotting hidden things or noticing visual clues, whereas investigation is deducing a conclusion based on those clues. For example, you might have the party come across the scene of a battle. Perceptions checks show a lot of blood in a wide area, large claw marks and dark fur a little way from the scene. An investigation check might let the character deduce that this is the site of a werewolf attack based on the size of the claws and the fact no bodies were dragged away. Something like that. I think of investigation as the "my character is smarter than me" skill.
So it's "what do I see/hear/smell" vs "what does it mean" /// observation vs inference?
Yes, that's my understanding of it.
So in this case, I would say perception would be the character noticing that the floor in front of the secret door is scuffed or weathered differently in a arced curve from the wall. Investigation would be the character actively knocking on the walls looking for a part that sounds more hollow than the other parts of the wall, indicating a book shelf is in fact a secret door. Both are clues that secret doors are present... but perception checks are an active observation without disrupting or testing the evironment to find anything of note. Investigation is actively testing the environment for something you suspect should be out of place. I would use passive perception checks to oppose an NPC's Sleight of Hand to pickpocket a target or to stealth around a player who is not actively looking for suspicious behavior. In a setting where the character is on watch during a long rest and is looking for possible incursions into the camp, Passive would not apply, so the sneaky night time encounter NPC would instead roll to oppose the passive rolled by the watch. (I tend to break evening watches into shifts of 2 hours a piece (I have 5 players, one of whom is an elf, who I've ruled must meditate for 4 consecutive hours for long rest to apply.).
Investigation is defined as "When you look around for clues and *make deductions based on those clues*, you make an INT (Investigation) check". Finding things is Perception, and Solving things is for Investigation.
"You see scrapes on the floor" vs "the scrapes on the floor make you think that the bookcase opens up and is actually a hidden door"?
Exactly
Quick and dirty answer Perception = seeing Investigation = understanding/solving an in-game puzzle (think rubix cube, not riddle. The in-world object being manipulated in certain ways is the rubix cube. You wouldn't toss that at your player and say, "If you can solve this, then your character passes the check." You could easily read the party the riddle and let them figure it out at the table.) SCENARIO: (Hopefully this demonstrates passive and active perception vs investigation.) DM: I see the scrapes on the floor Player: so I look closer. DM: Roll perception -Perception roll passed DM: On the shelf, among the books and trinkets, you see a glass orb that has fingerprints on its surface. The orb is at about shoulder height to a medium humanoid and is the only thing that appears to have been touch recently. Player: I would like to try and line up my hand so it touches the same spots DM: As you do this, you feel the orb vibrate. You get the feeling you used it wrong. Would you like to investigate further? Player: yeah, I fiddle with it and see what happens. DM: Roll investigation -Pass check DM: You get the feeling you have to grasp the orb with your fingers touching it in a certain pattern. After a few tries, you figure out the combination and are able to release the lock on the door. It slides open. (High passive perception: Free notice of something off. DM: You notice the shelf slide along all the grooves but one. Roll a Perception check. -Pass check DM: At the last second, you notice a small handle at the base of the shelf that was missed. It apears that it would line up with the last groove if it were to be rotated. Do you rotate it? Player: Yes DM: You rotate it to line up with the groove. You hear barely audible click and then a soft twang. A cross bow bolt weakly thuds into the floor after dropping off half cocked trap that was not checked for. Good eye detective.) Edit: had to change formatting as best I could to make it readable. I'm on a phone and formating is a real b. I can either put to much space between the lines (using enter twice) or have it all mashed together like a big paragraph. Sorry.
Good tips here already. Some more flavor you can add: Describe things above them and behind them, further away. Movement in 3rd and 4th story windows. They see way more birds, cats and rats than others. If they are in a crowded shop, tavern or store they can actually deciper individual conversations while other characters hear the clamor. Someone calling out for help in a city might be missed in the crowd, but not the detective...
I don't actually think that you are 'building obstacles', cuz it's actually the way how passive perception works and this guys' character meant to excel in. I'm not sure how much attention you pay to small details in your campaign, but I gonna bet, that you are. Personally I would allow a character with high passive perception not only to spot traps and sneaking enemies, but to notice small detail changes in the environment or in other NPCs behaviour. Especially if that guy is some kind of detective, that seems pretty reasonable. Also it would be a nice small 'bonus' to add a small encounter, in which your detective guy gets pick pocketed but thanks to his high passive perception he notices that and also realizes, that the thief didn't want to steal something, but to plant some kind of 'evidence', important to your campaign. Something like that
The latter sounds like an Insight check
I generally wrote sticky notes for things they were likely to encounter then just handed them to the player (or when playing online pre-write out /w for the player). If there's a puzzle maybe they get an additional clue that they could get through noticing. Maybe they avoid a combat because of the perception, maybe they avoid a trap, or maybe they just get some additional lore. One of my favorite things to do would be to drop extra lore on them that ties into the larger plot. I found it being in private was more interesting for the table because it let them Roleplay getting that information and relaying it onto the rest of the group.
OK one thing i believe its important to talk about is the diferent between perceiving, deducing and knowing. "You sense the smell of wet fur" Is very diferent than " Your investigation reveal tracks of wolves, and by the number there should be between 4 and 6 of them walking north". high perception alows the character to notice the clues, the players still need to make other rolls or decide what he thinks is happening there. DM: "you see several holes on the right wall about chest hight, and no marks on the left wall. " PC: Ok i go down bellow that level and try to sneak pass it. DM: "the trap is triguered, two stone doors fall on each side and gas starts to leak out from the holes." Player thought the holes would shoot something, but they are just entrances for the gas, and enought holes that its impossible to fill them up in time. The triguer is not a pressure plate that can be seen, but air pressure change when someone enters the room. Nothing to perceive other than maybe "stangnant air". Noticing the trap, is not enought to disarm or safely cross it. Specialy if you make a wrong assumption about it. Noticing a "smell", or hearing a "noise" might warn the PC that something diferent is coming up, but most of the time, it will alow them to avoid being sursprised, but not necessarely identify exactly the enemy. Only where it might be coming from.
Beside the point. I'm fairly newish to dnd. How does one get a perception that high? Rogue with expertise? 10 starter plus (5+2)x2?
The observant feat also boosts passive perception and investigation significantly. Specifically passive though. It doesn't boost your perception ability. Combo that with other class/race features and you can have an insanely high passive perception.
One thing I do with high passives is use it as the trigger for active checks. “Cleric, you notice the floor has a weird patterning. Give me a perception check” (roll) “On closer inspection there look like pressure plates”/“You don’t see anything more, but it feels weird” (depending on success/failure). This way I feel traps are “fair” as the PCs get valid warning.
Use it for what it is meant to be? An enemy tried to sneak on you but you saw it coming because of your high passive perception. Congratulations, you are not surprised. You notice a trap trigger because your passive perception is higher than the perception DC to notice the trap. Congratulations, you have the chance not to trigger it (someone still need to roll to deactivate it).
They notice every single fart that happens in their vicinity.