Another dark vision question

[Sean Pella]

Sorry if it’s been asked but with dark vision looking in dim light, that would normally be dark without dark vision, you wouldn’t need to roll a perception check to see someone just standing there or walking around right? Only if they were trying to hide. We have been playing that since it’s dim and obscured just to see someone standing there requires a perception check at disadvantage. It doesn’t make sense to me because if that were the case you would need to roll to see a table or chair. Not sure where we came up with this rule but that’s how we’ve been doing it. Thanks for any help.

 

[Leatherhead]

Every character has a "Passive Perception" score. This is the score you use to see things if you aren't actively looking (Which means spending an Action to use Perception skill.) Whenever you would have disadvantage on a normal Perception check, you have a -5 penalty to this score. This makes it significantly harder to see things in the dark.

So no, you don't have to roll to see a table or a chair with darkvision, that is what Passive Perception is for. HOWEVER: It is possible that your Passive Perception score is so bad in the dark that you can't see a table or chair that is in the same room as you, especially if someone else has taken the effort to Hide it.

 

[Sean Pella]

But what I’m saying is if we walk into a 10 x 10 foot room with dark vision and no light source and there are 3 orcs standing in there just hanging around do we need to roll a perception check to see them because it’s dim light and considered lightly obscured or would they have to be actively trying to hide?

 

[Leatherhead]

Passive Perception exists explicitly so that you don't ever have to roll a Perception check.

It's just that you might not see something by using Passive Perception.

Lets do some scenario math:
Assume you are playing as a somewhat bumbling Dwarf with a Wisdom Score of 8, and no proficiency in Perception.

Top figure out what your Passive Perception is, here is the relevant bit from the Rules:

Passive Checks
A passive check is a special kind of ability check that doesn't involve any die rolls. Such a check can represent the average result for a task done repeatedly, such as searching for secret doors over and over again, or can be used when the GM wants to secretly determine whether the characters succeed at something without rolling dice, such as noticing a hidden monster.
Here's how to determine a character's total for a passive check:

10 + all modifiers that normally apply to the check

If the character has advantage on the check, add 5. For disadvantage, subtract 5. The game refers to a passive check total as a score.
For example, if a 1st-level character has a Wisdom of 15 and proficiency in Perception, he or she has a passive Wisdom (Perception) score of 14.
The rules on hiding in the “Dexterity” section below rely on passive checks, as do the exploration rules.

This means that your 8 wisdom Dwarf has a Passive Perception of 9 (because of the -1 penalty for having 8 wisdom)
And while you are using Darkvision, your Passive Perception score drops to 4 (because of the additional -5 penalty from Disadvantage).

The typical DC range on ability checks is 5 (very easy) to 30 (nearly Impossible)

We can assume that seeing an orc in a Dark 10x10 room is a very easy task, and thus set the DC to 5. Unfortunately, this is greater than your Passive Perception of 4, so you do not see the Orc. Maybe you can't figure out there is an Orc in there because it is wearing a cloak and thus looks like a orc-sized lump of no consequence, or maybe you were daydreaming a little too hard about a nice ale to notice them.

 

[ad_hoc]

No, of course not.

You might be misinterpreting what dim light is.

The other thing you might be misunderstanding is what your passive perception is. Most of the time you're not going to make a wisdom (perception) check at all. Instead, hidden objects and creatures are checked against your passive perception. Disadvantage in this case giving -5 to the value.

 

[ClearlyTough69]

You're doing it right: if a creature is lightly obscured from you (which is what dim light does) but not behind cover, you still see it automatically unless it is trying to hide from you.

And despite what other respondents have said, you're interpreting dim light in the context of darkvision correctly. It took me a while to understand what you meant though!