Passive Perception vs. Perception Check

[DragonLord7]

My character has a very high Passive Perception through expertise and soon the observant feat. My question is that could I just use my passive perception for perception checks. Related question does making a perception check mean my passive perception even if higher doesn’t matter.

[solidork]

If you roll a perception check lower than your passive perception, use your passive perception score instead. Don't forget to include low light modifiers; if you've got darkvision and are in complete darkness you'll have a -5 to your passive perception.

If you roll higher, then use what you rolled.

[Man_Over_Game]

If you roll a perception check lower than your passive perception, use your passive perception score instead. Don't forget to include low light modifiers; if you've got darkvision and are in complete darkness you'll have a -5 to your passive perception.

If you roll higher, then use what you rolled.

There's some debate on this. The overall consensus is one of three things:


Passive perception is a minimum for all perception-based events, and is "always on". This means your perception checks can't be lower than this value, and any checks against this that aren't higher fail. This means you automatically notice everything who's stealth DC is below this threshold.
Passive Perception is used as a defensive or reactionary stat, used only when something happens that you were not looking for. Something stepping in the dark, or a glint of light in a pond fall into these categories. These are things that happen around you, and things you can miss. You use an active check if you are searching for something, which would likely go against their defensive stat (likely a stealth value of some kind).
Passive Perception is used when time is not a constraint. When you can spend as much time as you need to, your Passive Perception is the score you use. This is to avoid unneeded dice rolling, and to maintain pace. It also represents your character's ability to notice things when not under pressure.


Some DM's use #1, but I think that's lazy and overpowered for a skill that's already used too often.

Others use some variant of #2 and #3.

Ask your DM how he rules it, as it is a very controversial subject, and only they can provide the correct answer for you.

I personally use #2 and #3, as I've written them, which effectively means you would be good at noticing traps as they're sprung (so you can avoid being hit or help allies from being hit), but preemptively noticing them requires an active check on your part without any value from your passive perception. The exception may be if you say you are constantly looking for traps as you enter each room. For that, I'd default to you using your passive perception, requiring your concentration as you do so. Doing so would require more time than a standard check, but it's more thorough.

This both gives passive perception a mechanical difference from active perception and maintains flow of the game by removing unnecessary dice rolls.

[solidork]

Some DM's use #1, but I think that's lazy and too overpowered for a skill that's already used too often.

Others use some variant of #2 and #3. Ask your DM how he rules it, as it is a very controversial subject, and only they can provide the correct answer for you.

Let it be noted that Jeremy Crawford, one of the designers of the game, handles it according to #1 and talks about why (among other things) on a podcast you can listen to here: http://dnd.wizards.com/articles/features/james-haeck-dd-writing (I think, I can't actually click that link at work)

Obviously every DM is allowed to rule as they please, so check with yours.

[Pelle]

It could be useful sometimes to use different DCs for the Passive and Active check, if the Passive is just the general observation, and Active represent a specific action.

Example:
A big room, something is hidden in a secret compartment in a bookshelf.
Enter room, just casual observation of the room contents. Check Passive Perception, DC 20.
Character decides to look at the bookshelf specifically, maybe an Active Perception check, DC 10.
In this case you might have PP score of 19 and fail to see something initially, and then activly roll an 11 for a success.


Then again, if the character is going through every room, and studying every bookshelf, then you might already be using Passive for that as well.

[LudicSavant]

Passive Perception is used as a defensive or reactionary stat, used only when something happens that you were not looking for.
This is very clearly stated to be against RAI both in the rulebooks themselves and by Jeremy Crawford.

[Man_Over_Game]

This is very clearly stated to be against RAI both in the rulebooks themselves and by Jeremy Crawford.

Don't mean to sound condescending, but I'd be interested to read on this. Could you let me know where I can find more info on that in the books?

[LudicSavant]

Don't mean to sound condescending, but I'd be interested to read on this. Could you let me know where I can find more info on that in the books?

This is covered at multiple points throughout the rulebooks. One example would be the very first example of passive checks, though, here:


A passive check is a special kind of abilily check that doesn't involve any die rolls. Such a check can represent the average result for a task done repealedly, such as searching for secret doors over and over again.

This usage directly contradicts the notion that it is used "only when something happens that you were not looking for."

[Man_Over_Game]

This is covered at multiple points throughout the rulebooks. One example would be the very first example of passive checks, though, here:



This usage directly contradicts the notion that it is used "only when something happens that you were not looking for."

But don't the stealth rules contradict in the same way, then?

You don't actively look for someone repeatedly, but they do roll against your passive perception to hide from you. The same is true if you try to hide from them. They might not be looking for you, but you are still rolling against their passive perception.

If the stealth person beats the passive perception, they stay hidden and no longer need to roll against the passive perception until the unaware target begins searching for a hidden target (requiring an active perception roll) or until something forces another stealth check from the stealthy unit (like going through noisy terrain).

[LudicSavant]

But don't the stealth rules do the same, then? There is a very important difference between words like "sometimes," "always," "never," "only," etc.

"Orcs can be Fighters" and "Only orcs can be Fighters" are completely different rules.

[Man_Over_Game]

So your disagreement was less about the line as a whole, but mostly because that it was too specific from the word "only"?

Doesn't that feel kinda...pedantic?

I mean, even in my own example, I referred to using #2 and #3 together, which wouldn't make much sense if you took both lines as literal as possible. But I guess I understand where the confusion came from now.

[ad_hoc]

I like to have the PCs roll and have the monsters use passive stealth.

I think it is more fun in general this way and saves me from making a bunch of rolls for the monsters.

In this case I just give advantage for Observant because that is what the +5 is anyway.

[Louro]

It's a tool rather than a player's feature. A DM's tool to be precise.
Usually my players ask for perception rolls and that's fine, we roll. But sometimes I use PP to make fast rolls behind the screen, so they don't know something's going on.

Remember -5 PP in dim light (or any other disadvantage)

[Tanarii]

Passive perception is used whenever you're attempting to perceive thing (but not the same thing) repeatedly or whenever you don't know something is there. If you're taking time to check one place / look for one thing then that's the automatic success rule instead. It's also explicitly used against a creatures initial Stealth check.

Generally that means it's used the majority of the time, since you're looking for things that you don't know are there. If you do know something is there but can't find it due to a low passive perception, you'd use and action (if in action based time aka combat) and roll. That usually means a creature that just hid from you.

It's not actually a floor, but due to the nature of the check almost usually being a secret check, you'll almost always have used passive perception before you'd need to roll an active check. This makes observant or advantage on perception checks (sentinel shield) very good, since plus 5 to passive perception is a solid advantage.

You don't get to use passive perception if you're doing something so engrossing that it takes all your attention (examples given are Mapping, Foraging, Tracking, and Navigating) or if you can't see the thing (example given is not being in the front rank of marching order).

[Thrudd]

You don't get to decide when to use passive or to roll for perception, the DM does. They should be using passive whenever the character would not be aware that there is something to notice or is not actively looking for something. If you say you want your character to look or listen for something, that's when they ought to ask you to roll perception. Either way, it is their discretion. You should not be asking to make perception checks, or any sort of checks. You say what your character is doing, and the DM tells you if they want you to roll for anything.