D&D 5E Lighting Effects

FrogReaver · Jul 7, 2019

Suppose you have a PC and an NPC. The NPC is surrounded by total non-magical darkness but stands beside a torch. 20ft bright light radius and 20ft dim light radius. (assuming no darkvision)

Suppose the PC stands in the dim light area and the NPC is in the Bright light area. If the PC wanted to perceive something about the NPC does he have disadvantage? If the NPC want's to perceive something about the PC does he have disadvantage?

Now suppose the PC is standing

50 ft from the torch in the dark area

and the NPC is in the bright area.

Does anything change?

Now suppose the PC is standing 50 ft from the torch in the dark area and the NPC in the dim area. Does anything change?

Thoughts?

Sacrosanct · Jul 7, 2019

I wouldn’t give disadvantage except for two scenarios: the person being observed is in darkness, or the light source is in between the two parties directly and the observed member is in dim or darkness. The light directly in front of your eyes will adversely affect your night vision (real life version, not game version), so anyone on the other side who is on the fringes will be harder to see. That’s why lanterns were hooded and bullseye, because if the light also shone back in your eyes, you couldn’t see as far.

5ekyu · Jul 7, 2019

FrogReaver said:
Suppose you have a PC and an NPC. The NPC is surrounded by total non-magical darkness but stands beside a torch. 20ft bright light radius and 20ft dim light radius. (assuming no darkvision)

Suppose the PC stands in the dim light area and the NPC is in the Bright light area. If the PC wanted to perceive something about the NPC does he have disadvantage? If the NPC want's to perceive something about the PC does he have disadvantage?

Now suppose the PC is standing
50 ft from the torch in the dark area
and the NPC is in the bright area.
Does anything change?

Now suppose the PC is standing 50 ft from the torch in the dark area and the NPC in the dim area. Does anything change?

Thoughts?

The perception is based on the illumination at the target being observed. Unless any of the conditions provide obscuration the intervening areas do not matter.

So the guy next to the torch is observed as if in bright light - no penalties barring some special sensitivity.

The guy in dim light is perceived as in din light - rolls at disadvantage to see much about them but not unseen or hidden unless other factors apply.

The guy in darkness is unseen but not hidden - unless other factors apply.

This is why your Unseen Servant should be carrying the torch ahead of your group and night camp lighting should be on the perimeter unless your goal is to make it easier for areas right around you to be spotted.

Obviously, magical darkness and other obscuring effects change things a lot.

FrogReaver · Jul 7, 2019

5ekyu said:
The perception is based on the illumination at the target being observed. Unless any of the conditions provide obscuration the intervening areas do not matter.

So the guy next to the torch is observed as if in bright light - no penalties barring some special sensitivity.

The guy in dim light is perceived as in din light - rolls at disadvantage to see much about them but not unseen or hidden unless other factors apply.

The guy in darkness is unseen but not hidden - unless other factors apply.

This is why your Unseen Servant should be carrying the torch ahead of your group and night camp lighting should be on the perimeter unless your goal is to make it easier for areas right around you to be spotted.

Obviously, magical darkness and other obscuring effects change things a lot.

Can the guy in darkness see the NPC in the light?

Arvok · Jul 7, 2019

In RAW (as I understand them), the PC in darkness can't see the NPC in light. But, this is ludicrous and doesn't square with observable phenomena in the real world. Just talking normal lighting and vision (no darkvision which, btw, doesn't work like night vision devices do in the real world), the PC in darkness can easily see the NPC holding the torch. Even from very far away, the PC can see the torch light even if he can't quite make out what's inside the light. In my games, characters can see a light source at least 5 times as far as it provides light. In this case, the PC could be 400 feet away and perceive the torch light (though he wouldn't be able to see what exactly was in the torch light).

FrogReaver · Jul 7, 2019

Arvok said:
In RAW (as I understand them), the PC in darkness can't see the NPC in light. But, this is ludicrous and doesn't square with observable phenomena in the real world. Just talking normal lighting and vision (no darkvision which, btw, doesn't work like night vision devices do in the real world), the PC in darkness can easily see the NPC holding the torch. Even from very far away, the PC can see the torch light even if he can't quite make out what's inside the light. In my games, characters can see a light source at least 5 times as far as it provides light. In this case, the PC could be 400 feet away and perceive the torch light (though he wouldn't be able to see what exactly was in the torch light).

Do you also apply the same rationale to the Darkness spell?

FrogReaver · Jul 7, 2019

Sacrosanct said:
I wouldn’t give disadvantage except for two scenarios: the person being observed is in darkness, or the light source is in between the two parties directly and the observed member is in dim or darkness. The light directly in front of your eyes will adversely affect your night vision (real life version, not game version), so anyone on the other side who is on the fringes will be harder to see. That’s why lanterns were hooded and bullseye, because if the light also shone back in your eyes, you couldn’t see as far.

So you ignore the raw about dim light causing disadvantage to perception checks? Or is that only if both characters are in dim light?

Sacrosanct · Jul 7, 2019

FrogReaver said:
So you ignore the raw about dim light causing disadvantage to perception checks? Or is that only if both characters are in dim light?

I don’t have every rule memorized. And I don’t have a book handy. That’s how I would handle it if it came up in a game. If someone pointed out the rule, then I’d follow that or use that as guidance.

Satyrn · Jul 7, 2019

FrogReaver said:
Suppose you have a PC and an NPC. The NPC is surrounded by total non-magical darkness but stands beside a torch. 20ft bright light radius and 20ft dim light radius. (assuming no darkvision)

Suppose the PC stands in the dim light area and the NPC is in the Bright light area. If the PC wanted to perceive something about the NPC does he have disadvantage? If the NPC want's to perceive something about the PC does he have disadvantage?

Now suppose the PC is standing
50 ft from the torch in the dark area
and the NPC is in the bright area.
Does anything change?

Now suppose the PC is standing 50 ft from the torch in the dark area and the NPC in the dim area. Does anything change?

Thoughts?

I just consider the lightning conditions the "target" is in. No matter what lighting condition you're standing in, if you're looking at something in dim light, the dim light rule applies. If you're looking at something in bright light, the bright light rules apply.

Arvok · Jul 7, 2019

No. A darkness spell can only be perceived if someone could notice the area of darkness. So, at night a character might be able to see a torch at several hundred feet (because he could see the light in contrast to the lack thereof), but he wouldn't be to see the spot of darkness in a sea of black. If, however, a torch went into or behind the AoE of a darkness spell, an observer would see the torch suddenly stop shedding light. Depending on how far away the observer was from the torch he might suspect something unusual going on.