D&D 5E Applying advantage to passive Perception

[pukunui]

According to the rules for passive checks (PHB, p 175), having advantage on a check translates to a +5 bonus to the corresponding passive score.

Lots of monsters have Keen Senses, which grant them advantage on Perception checks under certain circumstances. Something I've done ever since the early days of 5e is make a note of this in monster statblocks.

For instance, a wolf has Keen Hearing and Smell, granting them advantage on Perception checks that rely on hearing or smell. By default, a wolf's passive Perception score is 13. Using the above noted rule, their passive Perception score would increase to 18 for the purposes of hearing or smelling. I make it so the Senses line in their statblock reads "passive Perception 13 (18 w/ sounds and scents)". I do this for all monsters / NPCs with a variation on the Keen Senses trait.

I'm just curious to know if anyone else does this, or am I the only one?

 

[iserith]

I don't do it. I just take it into account when I'm resolving the PCs' attempts to be stealthy.

 

[Quickleaf]

Yeah, when I take the time to rewrite monster stats into my notes, I do the exact same thing. I kind of feel it's something that should just be integrated into the Senses/passive Perception line of the monster stat block.

 

[GMMichael]

For instance, a wolf has Keen Hearing and Smell, granting them advantage on Perception checks that rely on hearing or smell. By default, a wolf's passive Perception score is 13. Using the above noted rule, their passive Perception score would increase to 18 for the purposes of hearing or smelling. I make it so the Senses line in their statblock reads "passive Perception 13 (18 w/ sounds and scents)". I do this for all monsters / NPCs with a variation on the Keen Senses trait.

Well done on the note-taking.

But why would a DM make a passive perception check for NPCs? I don't see the point in adding notes to monster sheets that don't need to be there.

 

[pukunui]

Well done on the note-taking.

But why would a DM make a passive perception check for NPCs? I don't see the point in adding notes to monster sheets that don't need to be there.

Whenever a PC rolls a Stealth check, I compare it to the passive Perception score of any monsters or NPCs in the area.

Sticking with the wolf example - because of their keen ears and nose, a wolf is hard to sneak up on because they might hear or smell you coming before they can see you. In my mind, that's worth noting in the statblock.

 

[Faolyn]

The PH says to add or subtract 5 from the passive skill if the creature has advantage or disadvantage.

 

[pukunui]

The PH says to add or subtract 5 from the passive skill if the creature has advantage or disadvantage.

Correct. And as I mentioned in the OP, lots of monsters have advantage on Perception checks, so I like to make a note indicating that their passive Perception score is 5 higher for the applicable circumstances (like hearing and smell for a wolf). I was just curious to know if anyone else does that as well.

 

[Horwath]

yes.

that is why you have guard dogs, so it's hard to get a jump on you.

 

[Lyxen]

Lots of monsters have Keen Senses, which grant them advantage on Perception checks under certain circumstances. Something I've done ever since the early days of 5e is make a note of this in monster statblocks.

I resolve things this way, but one thing I don't do is to add it as a note, I usually remember it without too much trouble by visualising the type of creature, they are fairly logical after all.

One thing I don't do for sure is add it to the score, because I had a player on a forum being adamant that his owl familiar had 18 perception, which is simply not true.

In particular the owl had darkvision, but in complete darkness, she only sees as well as in dim light, and the disadvantage of that compensates the keen senses if the detection mean is sight (instead of smell). If it's hearing, it could be the same way with ambiant noise. And because multiple sources of advantage/disadvantage just cancel each other, it's important to remember that the base passive perception is only 13.

 

[pukunui]

In particular the owl had darkvision, but in complete darkness, she only sees as well as in dim light, and the disadvantage of that compensates the keen senses if the detection mean is sight (instead of smell). If it's hearing, it could be the same way with ambiant noise. And because multiple sources of advantage/disadvantage just cancel each other, it's important to remember that the base passive perception is only 13.

That's not how I would rule it. Dim light only imposes disadvantage on Perception checks that rely on sight. I wouldn't have that disadvantage cancel out the advantage on Perception checks that rely on hearing. So I would say that the owl might be able to hear something without being able to see it.

(I'm willing to be nuanced about Perception -- treating sight, sound and smell as separate things.)