Darkvision: A PSA

[E’Tallitnics]

I'm creating this PSA because I thought I understood how Darkvision works in 5e, but recently found out I had it wrong.

It was my understanding that in complete darkness a creature with Darkvision could see as if it were Bright Light within the radius specified by their Darkvision, and as if it were Dim Light beyond that radius.

Nope!

The creatures' Darkvision radius just raises the light level within that radius.

Darkness becomes Dim Light. Beyond that radius it is still Darkness (Heavily Obscured). Within that radius you cannot perceive colors, just shades of gray. (Fire Gensai in shades of red.)

Dim Light becomes Bright Light. Beyond that radius it is still Dim Light (Lightly Obscured). No color perception restrictions.

The Warlock Invocation "Devil's Sight" allows the character to see Normally in Darkness (i.e. in full color and as if it were Bright Light) with a radius of 120', regardless if the Darkness is naturally occurring or magical. Beyond that radius it is still Darkness (Heavily Obscured). This ability does not affect Dim Light conditions.

In all of the above examples, if you're effectively in Dim Light conditions you still have Disadvantage on Wisdom (Perception) checks.

[Corran]

In all of the above examples, Dim Light still results in Disadvantage to Wisdom (Perception) checks.
I believe you wanted to write, effective dim light, instead of dim light. As you clearly state that a character with darkvision can see in dim light as it if was bright light, and hence, no disadvantage on perception checks.

Everything seems to be correct, I would add that the only way to never have disadvantage on percpetion checks, is to have both devil's sight and darkvision. Devil's sight not working in dim light, is something that is often missed by many people.

[Dalebert]

I knew most of this, including the Devil's Sight thing which apparently came up in a Mearl's tweet or something. What I discovered from this discussion is that Darkvision doesn't always affect your perceptions in dim light. All Darkvision does by default is make total (non-magical) darkness appear as dim light within the radius. The monster version and many racial versions of it (probably all, I think) say that it makes dim light appear to be bright light. As far as I know, this may only come up with the spell. If you cast Darkvision on someone, they can now see in non-magical darkness as dim light to 60 ft but it has no effect on perceptions in dim light.

Here's a bigger deal though. I bet hardly any DMs are taking this into consideration when you have a character hiding in total darkness. Monsters should have disadvantage on sight perception rolls. A really good scout in total darkness is one with Devil's Sight because the scout gets a chance to see enemies before they can see him. They could hear him, but distance should affect that and 120 ft is pretty far. Even 60 ft is pretty far for hearing something depending on the conditions.

Think about this. If you're playing an assassin and you REALLY want that surprise round, you might want to consider a brief warlock dip. Even better if you can play a dark elf.

[hymer]

What's PSA short for? I mean, in this case.

[Dalebert]

Player Sight Announcement

[jkat718]

What's PSA short for? I mean, in this case.

Dalebert' joke aside, PSA is typically understood to mean "Public Service Announcement" in this sort of context.

[E’Tallitnics]

Player Sight Announcement

Bah ha ha ha ha!!!

Thanks Corran. I've updated that last line to be clearer.