Perception vs Passive Perception

[Pope Scarface]

How do you run these? Not a rules question but more of a what do you actually do in your games, or your DM does.

[Mjolnirbear]

I use Passive for everything. If they are not paying attention, they get minus five to their score to represent disadvantage.

The sole exception is contests, such as vs Stealth. Then they roll as with any contest.

Edit: it bears mentioning, but I treat all knowledge as passive. You either know it, or you do not. This includes all skills, including a theoretical Athletics knowledge check to identify that famous wrestler. An active skill use, such as a roll to dispel a magical Glyph using Arcana, is likewise always a roll. In this respect, Perception has both an active and passive component in my games.

[MrStabby]

Basic rule for me is "do the players know they are using it?"

If players want to wake up from sleep hearing approaching footsteps, then that's passive. If a player wants to listen at a door that's active.

DCs don't have to be the same for the two tests though. You can have a person on watch listening constantly for sounds who can roll lower than their passive perception would be. In this case I may ad hoc a kind of reliable talent rule (so higher of active and passive perception).

[Demonic Spoon]

Passive perception is too rigid and unchanging to be broadly useful when directly contesting a player's stealth check. However, it's a great way of setting a "base" DC, which you can then add or subtract from based on circumstances.

[Boccobsblog]

I agree with the previous posters.

I use passive if they're not actively looking, walking past a secret door or trap. I use perception when they ask to observe their surroundings.

[Pope Scarface]

So far I have been using the monster's passive perception as the DC for group stealth checks (half the party has to succeed to avoid the monster, or the ones that succeed get a surprise round for pre-fight stealth). I'm not sure how well that will continue to pan out (hence the post).

[Segev]

The 5e game I'm in, the DM doesn't seem to ever use passive perception. I wouldn't have a problem with this, except there is that feat that gives +5 to passive perception (but not active), and I think one of the other PCs has said feat.

I also think it bad design to give a bonus that applies ONLY to passive perception.

[Joe the Rat]

I also use it as a "hide something" DC. I also find it cuts down on the crappy roll pile-up (where everyone starts rolling) on watch rolls when traveling and camping. It's also really good for situations where you don't want the party to know there's something to perceive.

Active is for when they are searching for something - they know there is something there.

[Naanomi]

For me: Active (takes an action); Passive (takes no action)... applied to almost all skills in some fashion

[Mr.Moron]

If anything that's trying to sneak against them rolls against passive perception. If anything might be otherwise hidden check against passive perception to see if it is simply obvious to them. If they decide to actively look for something they can additionally roll perception, and the additional effort may yield better results than what they find passively.

If say something snuck up them passed their passive perception but on the off chance before the creatures struck or whatever they decided "Hey lets check to see if anything is sneaking up on us, I just have feeling" they'd actively roll and if they beat the original stealth check (assuming I remember the result) they'd pass. If I've forgotten the original stealth roll result I'd just make a new one.



The 5e game I'm in, the DM doesn't seem to ever use passive perception. I wouldn't have a problem with this, except there is that feat that gives +5 to passive perception (but not active), and I think one of the other PCs has said feat.

I also think it bad design to give a bonus that applies ONLY to passive perception.

Seems this is more a problem with the feat than the general system.

[Naanomi]

Do note that with Observation Feat and Observant (and without any oddball bonuses like Guidance); one's Passive Perception is as good as your maximum roll for Active Perception

[Tanarii]

It's explicitly used vs Stealth, including for detecting ambushes, automatically and without action.

Other than that, it's the same as any other passive skill: it's used when the PC is doing something over and over again (ie actively searching over a period of time), or when the DM needs to keep the fact a check was even made secret (typically noticing a clue that something is hidden).

IMO it's one of the most abused & overused (by DMs) skills. It's not supposed to be radar. If you can't possibly detect something, it doesn't detect it, just as any other skill. No opposed check or 'roll' needed. If you automatically detect something, no opposed check or 'roll' needed.

And most important, other than opposing stealth which has a special callout rule, it should still require active searching on the part of the PCs. Despite the name, passive checks means 'doing repeatedly or need secret resolution' not 'not actively acting'.

Edit: that last is mostly important if a character is doing something else explicitly. As a DM you can pretty much assume any character in a dungeon or dangerous area that is not explicitly doing something else, is searching. You don't always need a player to tell you they're searching, you can use common sense. But what's important is if a player is explicitly doing something else, they shouldn't get to use passive perception. (Note that the traveling rules make this explicit for opposing stealth checks for purposes of determining surprise.)

[Segev]

Seems this is more a problem with the feat than the general system.

I would agree. The feat doing that is bad design. I didn't mean - though I see how it could have been interpreted that way - that passive perception is bad design.

[JumboWheat01]

The 5e game I'm in, the DM doesn't seem to ever use passive perception. I wouldn't have a problem with this, except there is that feat that gives +5 to passive perception (but not active), and I think one of the other PCs has said feat.

I also think it bad design to give a bonus that applies ONLY to passive perception.

It also gives a boost to passive Investigation, which... I'm not sure how that really works. When you Investigate something, you're actively looking for it.

The way my DM does it, Perception is always passive, which covers things like the old Spot and Listen skills of 3.5, while Investigation is always active, focused search, like the old Search skill could be in 3.5. So you could know of something being around, and be wary for it, but unless you went hard-searching for it, you couldn't actually find it.

This makes the rogues in our group, like my lil' halfling one from a while back, particularly well liked, since Perception and Investigation are on the skill list.

[Tanarii]

It also gives a boost to passive Investigation, which... I'm not sure how that really works. When you Investigate something, you're actively looking for it.When you use perception, you're also actively looking. With the exception of Stealth in Combat, which seems to allow for not actively looking, unless you assume that people in combat are always actively looking.

Edit: Note that passive perception allows for 'distracted' if you aren't really actively looking all that hard (-5 to check) and in the traveling rules explicitly calls out doing something else (ie not actively looking) as not allowing a check at all.

[Demonic Spoon]

Where did this concept that a "passive" check means you aren't paying attention come from?

A passive check in 5e is a DM tool to adjudicate certain kinds of checks by removing the random factor. It says absolutely nothing about whether or not the character is "Actively" doing something.


If anything, I think people have it reversed. If you're trying to get super simulationist with your die rolls, I would expect a character that is actively trying to do something to be more consistent, whereas a character that isn't actively searching for something would be more likely to either stumble upon it or miss it entirely (hence the randomness of a d20).

[Tanarii]

Where did this concept that a "passive" check means you aren't paying attention come from?For passive perception specifically: A combination of old edition rules, literal interpretation of the word 'passive', and the fact that vs Stealth it explicitly doesn't require any special action or declaration of intent.

[Mr.Moron]

I would agree. The feat doing that is bad design. I didn't mean - though I see how it could have been interpreted that way - that passive perception is bad design.

I also didn't meant that you meant that, more that I was just calling it out specifically. My phrasing could have been better. I personally dislike the feats we have, and that dislike really just grows and grows the more people point out the edge cases. I like the general framework of the system mind you, I just the think the actual content built around it is poor, and the consequences of them weren't well considered. Like the rushed it out at the last moment and slapped the "Optional Rule" tag on it just to avoid having something spotty attached to the core.

[DivisibleByZero]

I have/use passive scores for practically everything, with my passive base at 8+SkillMod (like save DCs). If the players state that they're doing X (or if it's obvious that they *would* be doing it), they roll. If they do not state it (or it isn't common sense that they'd be doing it), then they use passive.
Passive scores are minimum rolls, unless the situation allows that they might do worse.

Secret door, as an example:
Not looking, distracted (by combat, etc): no chance
Not looking, without distractions: passive (8+mod)
Searching, without distractions: roll (passive score minimum)
Searching, distracted: roll (no minimum)

Doing it this way seems more realistic to me, it makes things such as the Alertness feat matter (quite a lot), and it speeds up play in many cases.
It also keeps the Rogue's ability from being redundant, as I use 8+ and still allow for situations where you can do worse than passive if distracted, both of which get trumped by the Rogue's ability.
It works quite well for our table.

[Tanarii]

I have/use passive scores for practically everything, with my passive base at 8+SkillMod (like save DCs). If the players state that they're doing X (or if it's obvious that they *would* be doing it), they roll. If they do not state it (or it isn't common sense that they'd be doing it), then they use passive.
Passive scores are minimum rolls, unless the situation allows that they might do worse.That's pretty much the opposite of how passive is intended to be used.

Normal rolls are supposed to be for when they declare they're doing something and its pass or fail at this immediate moment.

Passive checks are supposed to be for when they declare they're doing something, and instead of declaring they're doing the same thing over and over again every round, you use a passive check over the time period for the on-going task, as the average on any given round.

[DivisibleByZero]

That's pretty much the opposite of how passive is intended to be used.
No, it's simply taking the concept from A and moving it along what we consider to be its natural progression to B.
Its not the opposite, it's a continuation.

[Tanarii]

No, it's simply taking the concept from A and moving it along what we consider to be its natural progression to B.
Its not the opposite, it's a continuation.
Nah, it's the opposite mate.

It's a workable house-rule though. Common too.

[Vogonjeltz]

Passive checks are supposed to be for when they declare they're doing something, and instead of declaring they're doing the same thing over and over again every round, you use a passive check over the time period for the on-going task, as the average on any given round.

That's just one use from PHB 175; Another listed in the same paragraph is to secretly determine if the character succeeds at something without rolling dice, such as noticing a hidden monster.

Yet a third use is the rule on PHB 177, which is that the Perception score also reflects non-active awareness:
"there's a chance someone will notice you even if they aren't searching"

[Regitnui]

"Wait, did you hear that?" vs "That sounds like a hungry rust monster".

One is not paying attention but it caught your notice anyway, and the other is you're actively listening/looking for something. Investigation is then taking the evidence from Perception and interpreting it. "That sounds like a hungry rust monster" to "The rust monster's moving away from us. Walk softly and it might not notice our equipment".

[Plaguescarred]

Passive it not in regards to the player characters, but the check itself, therefore i use a passive check when i don't want to involve any die rolls, this wether it's to determine the outcome for an average result for a task done repeatedly, or when to secretly determining the outcome of a check without rolling dice.

That the player characters know about something or not, a check could always be called for something not actively done so i.e a intelligence or wisdom check to see if something is recalled or spotted. It's all about dice rolling simplification method instead or take 10 if you prefer

[Tanarii]

That's just one use from PHB 175; Another listed in the same paragraph is to secretly determine if the character succeeds at something without rolling dice, such as noticing a hidden monster.

Yet a third use is the rule on PHB 177, which is that the Perception score also reflects non-active awareness:
"there's a chance someone will notice you even if they aren't searching"
AFB so I'll have to check it out later. Because I thought the rules were clear that kind of thing only applied in opposed to stealth check situations. What chapter and section is that under, and is it in a sidebar?

And then admit I'm wrong if it's something other than vs Stealth, dammit. :smallwink:

[Demonic Spoon]

AFB so I'll have to check it out later. Because I thought the rules were clear that kind of thing only applied in opposed to stealth check situations. What chapter and section is that under, and is it in a sidebar?

And then admit I'm wrong if it's something other than vs Stealth, dammit. :smallwink:

It's in the sidebar for "Hiding"; it only refers to stealth.

[Vogonjeltz]

AFB so I'll have to check it out later. Because I thought the rules were clear that kind of thing only applied in opposed to stealth check situations. What chapter and section is that under, and is it in a sidebar?

And then admit I'm wrong if it's something other than vs Stealth, dammit.

Well, the citations were all from Chapter 7, which starts on page 173.

First two examples (the one you listed, and the other) are 175 under the heading "Passive Checks"
The third example is listed in the sidebar "Hiding" on 177 under the heading "Passive Perception" (halfway down the sidebar).

It is referenced again in Chapter 8: Adventuring, on pages 182-183 under the section heading "Activity While Traveling" and "Noticing Hidden Threats" and also "Other Activities": "Use the passive Wisdom (Perception) scores of the characters to determine whether anyone in the group notices a hidden threat."

The third example from is also referenced in the DMG:

DMG, page 243 under the heading "Noticing Other Creatures":
"If neither side is being stealthy, creatures automatically notice each other once they are within sight or hearing range of one another. Otherwise, compare the Dexterity (Stealth) check results of the creatures in the group that is hiding with the passive Wisdom (Perception) scores of the other group, as explained in the Player's Handbook."

This also applies to traps, per the DMG on page 121, Chapter 5: Adventuring Environments, under the subheading of "Detecting and Disabling a Trap":
"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."

The Observant feat in the PHB also increases the passive Intelligence (Investigation) score of the character. In combination, this all suggests that Passive scores are useful anytime where a character might do something without actively doing it, just like it says on the tin.

Initiative scores are also mentioned as an alternative and quick method of determining turn order, in the combat options section of the DMG.