D&D 5E Perception in 5e, discuss how it works

[Sadrik]

So we have several skills that allow characters to notice things and we have several mechanics applied in different ways on how to determine if they sneak, pass the lie, or leave tracks that are not discoverable.

The skills and what they can identify:
Perception detect the presence of something (examples given: hear a distant conversation, eavesdrop, listen for a stealthy montster, spot obscured things, determine ambush, notice a hidden creature, find a secret door)
Investigation look for clues, pierce illusions (examples given: deduce fact from clues, figure out what killed a victim, deduce weak point in cavern, find clue in books)
Insight notice true intentions of a creature (examples given: detect lie, anticipate a creatures next action)
Survival detect natural things (examples given: follow tracks, find safe passage through hostile terrain, notice markings that a hostile creature lives nearby, sense weather changes, notice dangerous natural phenomena (quicksand etc.)

Then we have several mechanics:
Passive Perception

I could also see the utility in creating:
Passive Survival
Passive Insight

I would not do Passive Investigation as this seems more like something you actively do and not something you passively do.

Ultimately there is a lot of carry over between these 4 skills.

If the party is walking through the forest would the DM ask for passive perception to avoid the pit trap or would they ask for survival rolls or would they ask for both?

While inside with a pressure plate with the DM ask for passive perception or investigation rolls to find it?

While outside and an invisible opponent in a grassy clearing, would the DM ask for a survival roll, a passive perception, a perception/stealth contest, or investigation (illusion)?

While at a merchant guild would the DM call for an insight/deception contest or passive perception or investigation roll or something else to determine if the merchant is lying and selling false wares?

So while I can see there can be multiple mechanics to handle one thing, I think this instance could be cleaned up. Perhaps it does not need to be cleaned up and the game has enough breadth to allow all of these instances and more. I think that is a strong way to approach the situation. I only wonder because it is not clear, how will you handle these situations when in game? Are there drawbacks to any one mechanic:
Passive score
Contest
Vs. a DC

Perhaps each skill should be used only with one mechanic and others should always be others? Thoughts on this?

 

[GX.Sigma]

My answers:

If the party is walking through the forest would the DM ask for passive perception to avoid the pit trap or would they ask for survival rolls or would they ask for both?

Passive perception to notice that there's a weird-looking clump of leaves; if they do and decide to investigate, they can use Nature, Survival, or Investigation.

While inside with a pressure plate with the DM ask for passive perception or investigation rolls to find it?

If it's visibly different from the rest of the floor, they get a passive perception check. If they're specifically checking the floor for traps, they can roll investigation.

While outside and an invisible opponent in a grassy clearing, would the DM ask for a survival roll, a passive perception, a perception/stealth contest, or investigation (illusion)?

The hiding creature rolls stealth vs. everyone's passive perception. If a player wants to spend his turn looking for the invisible creature, they can make a perception check (I'd also allow Investigation and/or Survival in this situation).

While at a merchant guild would the DM call for an insight/deception contest or passive perception or investigation roll or something else to determine if the merchant is lying and selling false wares?

Passive perception if there's a chance to casually notice. If the players suspect something, they can try insight or investigation.

 

[jgsugden]

Perception is the skill to let you know if something exists.

Once you know it exists: survival, insight and investigation let you understand more about it.

A DM might require no perception (but require an investigation/etc...) roll if the clues are easy to see, but hard to understand. On the other hand, if there is a small detail that is hard to spot, but has obvious significance (like a smear of blood on a red carpet), the DM might not require an investigation roll, but would require a perception roll to spot.

A pit trap or pressure plate might require both a perception roll to notice, and a survivial/investigation roll to figure out what it does.

Example: The PCs are traveling through the forest. A hidden pit is in front of them. One of the front rank PCs has a passive perception high enough to note that there is something off. The DM tells that player that he has noticed that there are leaves piled oddly on the trail ahead. The DM rolls a check for the players to determine if he figures out what it is. However, that PC does not have a high nature, investigation or survivial and fails. He stops the party and points to the pile of leaves and tells the rogue in the back of the party to check it out. The rogue investigates and determines that it is a pit trap. He uses deception and tells the dwarf it is just a pile of leaves. The dwarf walks across and falls into the pit. Much hilarity follows.

Another example: The PCs are sitting in a tavern getting a good drink on. There are rotting corpses piled in a closet, their pungent smell disguised by fragrances that the murderers left behind. The high passive perception PC notes that there are a lot of flies in the room. However, he doesn't have a high enough investigation or nature roll to note that this may mean that there is carrion nearby. The DM tells him that there are a lot of flies buzzing around his mead, and makes no reference to the rest of the group of anything amiss.

Another example: Bob has a high survival score, but lousy perception. He has been trained how to follow a trail, but is lousy at spotting the signs of a trail by himself. As the group tries to follow a trail, he might need the help of the keen eyed elf druid to spot the signs of passage, but he is the guy that tells the elf druid what to be on the look out to see...

Another example: The PCs come across an overturned wagon. The high investigation PC takes a look. The DM determines that there is no need for a perception roll because everything that needs to be seen to figure out what took place is right there in front of everyone... you just need to put the puzzle pieces together correctly.

 

[Sadrik]

Perception is the skill to let you know if something exists.

Once you know it exists: survival, insight and investigation let you understand more about it.

I think this is a very workable solution. If you allow me to plus you on this. So perception skill gives you a basal ability to notice things and then Survival, Insight and Investigation are used to determine the details.

I can see perception always being passive in this type of rules explanation and then to determine more you would go to one to the active skills, Survival, Insight and Investigation.

You might sense something is wrong when talking to the merchant (Passive Perception) and then with the player interest peaked they might say I try and find out what is wrong with the merchant and the DM says make an Insight roll. The player and DM then roll a insight/deception contest and determine what happens next. If the player's character had not had enough passive perception, then he would never have gotten to the second step of the contest.

You could take this same example and do it with a hidden or invisible character being detected by a guard. Does the guard have enough passive perception to detect the stealthy character. If he does then the guard could go to an investigation or survival contest against stealth of the sneaking character.

Then for the trap or pit (inside/outside) if the characters are actively looking for a trap or pit then they would use their skill actively if they were not actively looking then they would default to their passive perception. If they do not have the requisite passive perception and are not actively searching then the trap is sprung.

A very workable solution for how to work these rules.

 

[Sadrik]

I was reading through the vision and light section and it says lightly obscured gives you disadvantage on Perception (WIS) checks. It also says elsewhere this equates to -5 Passive Perception. So Bob the fighter with 12 WIS has a passive perception of 6 while in rain or fog or dim light, non-existent perception. I would assume that this would also carry over to the other three other Notice/detect skills: Investigation, Insight, and Survival.

I think that would be how I would rule it. Thoughts?

Edit: Additionally the Search action should include Survival and Insight as possible skills that should be available for this action.

 

[Li Shenron]

Indeed there's a lot of blur between the different skills and checks options, but it's good to see them as more and flexible opportunities rather than a rigid system to sort out.

I tend to see Perception as a description of your general awareness of things that are not expected, that stand out, be them visual, audible, smell, taste or something else. But also, I see Perception as something to use particularly when you don't know what you're looking for. Not strictly passive however, i.e. I would use Perception also for actively listening at a door, or for looking into the distance. Instead, I tend to see Investigation as trying to seek a specific target, either you're looking for an object (or object type) or an answer. But at the same time this could also be a difference between Wisdom and Intelligence in general.

The mechanics (passive vs roll, hidden vs shown to the players, retry or not, how long it takes or how long before another check) serve different purposes. IMHO the main use of passive perception might be for encapsulating multiple routine checks, but it's just an option and because of that it can also be used with Investigation or other skills. I'm not sure I'll use it often because you can't reach your highest DC. I would prefer hidden rolls if I don't want the players know about a failure, or regular rolls when they will find out anyway.

Then there is also the variant rule for using different abilities with a skill, which I plan to use quite often instead, but not letting the players choose, instead letting the circumstance establish that. I really like the idea that a detective may need a Wisdom(Investigation) check when looking for any clues in a crime scene, an Intelligence(Investigation) check to put the clues together and figure out how the crime actually took place, a Charisma(Investigation) check to gather information from people, and a Constitution(Investigation) check to sort out data from an archive in a night's work.

I am sure I won't always adjudicate these below in the same way, but here's what I'd do:

If the party is walking through the forest would the DM ask for passive perception to avoid the pit trap or would they ask for survival rolls or would they ask for both?

Since the trap is fixed DC, I'd avoid using passive and make a hidden group Wisdom(Perception) roll.

While inside with a pressure plate with the DM ask for passive perception or investigation rolls to find it?

Same, hidden group Wisdom(Perception) vs DC.

While outside and an invisible opponent in a grassy clearing, would the DM ask for a survival roll, a passive perception, a perception/stealth contest, or investigation (illusion)?

Regular (non-hidden) individual Wisdom(Perception) checks vs Dexterity(Stealth), assuming the enemy is going to attack the party anyway.

If the opponent won't start a fight but will stay there hiding, then hidden group Wisdom(Perception) vs Dexterity(Stealth), but in this case passive Perception may be ok (there is still randomness because it's an opposed check).

While at a merchant guild would the DM call for an insight/deception contest or passive perception or investigation roll or something else to determine if the merchant is lying and selling false wares?

Hidden group Wisdom(Insight) check vs Charisma(Deception), or once again passive Insight is ok.

That said, in all these examples you can also decide not to roll anything until the players say they actually want to check. It depends if you prefer playing by "the characters are assumed to be doing their best all the time" or "the players always need to declare".

Perhaps each skill should be used only with one mechanic and others should always be others? Thoughts on this?

My bottom line is that we've got plenty of mechanics:

- using different base abilities
- using different skill proficiency
- passive vs check
- player rolls vs hidden (DM rolls)
- individual check vs group check
- static DC vs opposed contest
- automatic vs player-initiated
- retries (dis)allowed

and too many possible in-game and meta-game circumstances to keep fixed on how to handle each case.

 

[Sadrik]

Indeed there's a lot of blur between the different skills and checks options, but it's good to see them as more and flexible opportunities rather than a rigid system to sort out.

I am not willing to make a determination on if this is good or bad, I think time will tell and even then it will likely differ table to table.

I think just from a complexity perspective, people will not naturally play it rules as written. They will have to wrap their heads around it to get close to RAW but even then it is not clear and leaves areas for interpretation. There are a lot of groups where "By the RAW" is the almighty and this is likely to confound some of those groups. The RAW is there is no one fit and it provides multiple avenues of Perception with multiple mechanics for multiple different situations. For gamers who like clear like clear 1 to 1 relationships with their skills and tasks this will present a problem.


Your rules interpretation is not how I would do mine (you are missing survival skill in some of those cases). Though I think we can agree each group will do perception slightly different. I also feel like that is not an issue that the game is agile enough to be able to handle each iteration and not suffer for it.

My bottom line is that we've got plenty of mechanics:

- using different base abilities
- using different skill proficiency
- passive vs check
- player rolls vs hidden (DM rolls)
- individual check vs group check
- static DC vs opposed contest
- automatic vs player-initiated
- retries (dis)allowed

and too many possible in-game and meta-game circumstances to keep fixed on how to handle each case.

I will remove contests in all cases due to the math issues and go with a passive check defense against the active character (a minor change but shores it up nicely).

I have not settled into if I will use other stats with the skills yet. If I do do that I will likely alter the skill list.

The new group check rule I have not wrapped my head around yet. On its face, it seems workable. So two rogues and a fighter are sneaking down the hall and the two rogues make the check the fighter fails. So they sneak... Ok. Two fighters and a rogue sneak down the hall two fighters fail and the rogue makes it. So they are noticed. IDK, I have not played the game enough to form an opinion yet on this.

Reactive skill checks vs active skill checks, I think you are talking about surprise, roll and see if you are surprised and I search for the tracks, roll to see if you uncover any tracks in this area... This can be a little messy, though most people will intuit the situation correctly I think. Saves are always reactive. Skills are not always reactive. For this reason, I was a proponent in making perception the WIS save. This would clarify its use - always reactive. Other skills would be used to actively perceive. As a house rule I may explore this but it does deviate somewhat from the RAW.

Also skill challenges are missing. You might need a certain number of successes before failures to succeed at a task. Pulling directly from the "death save" you could develop clean system.

 

[timbannock]

I think this is a very workable solution. If you allow me to plus you on this. So perception skill gives you a basal ability to notice things and then Survival, Insight and Investigation are used to determine the details.

I can see perception always being passive in this type of rules explanation and then to determine more you would go to one to the active skills, Survival, Insight and Investigation.

You might sense something is wrong when talking to the merchant (Passive Perception) and then with the player interest peaked they might say I try and find out what is wrong with the merchant and the DM says make an Insight roll. The player and DM then roll a insight/deception contest and determine what happens next. If the player's character had not had enough passive perception, then he would never have gotten to the second step of the contest.

You could take this same example and do it with a hidden or invisible character being detected by a guard. Does the guard have enough passive perception to detect the stealthy character. If he does then the guard could go to an investigation or survival contest against stealth of the sneaking character.

Then for the trap or pit (inside/outside) if the characters are actively looking for a trap or pit then they would use their skill actively if they were not actively looking then they would default to their passive perception. If they do not have the requisite passive perception and are not actively searching then the trap is sprung.

A very workable solution for how to work these rules.

Quite.

I think active Perception rolls are really only going to happen when a character is, for example, on watch and actively patrolling the camp's perimeter, or something to that effect. It's a situation where other skills won't play in until something comes up, but the character is making a concerted effort to listen, look, sniff about until something seems out of place. If they do, they can then resort to other skills to figure out exactly what the issue is.

But yeah, I think active Perception checks will be a fair bit rarer than passive Perception score use, overall.

 

[jgsugden]

In practice, so far, I've been using perception when something is hard to detect and the other skills to determine what something is once detected. It works fine, as long as you don't go crazy on making PCs roll perceptions for everything.

 

[Nemio]

What if you roll actively for Perception and have a lower result than your passive perception?

For example when the group is in marching order and they've let you know that they want to watch for traps.