Something That Never Made Sense: Light Radius

[GX.Sigma]

I never understood why light has a radius in D&D. It doesn't even make, like, physical sense. What is "bright light in a 20' radius?" After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

Since we're going back to the beginning and simplifying the game, maybe we should re-examine this concept. In real life, light doesn't really have a "radius;" its ability to light a large space depends on how bright it is. So why don't we just have a few classes of light (daylight, bright light, dim light, darkness), and adjudicate it that way?

Any other ideas on light and radius?

 

[Neonchameleon]

I never understood why light has a radius in D&D. It doesn't even make, like, physical sense. What is "bright light in a 20' radius?" After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

Since we're going back to the beginning and simplifying the game, maybe we should re-examine this concept. In real life, light doesn't really have a "radius;" its ability to light a large space depends on how bright it is. So why don't we just have a few classes of light (daylight, bright light, dim light, darkness), and adjudicate it that way?

Any other ideas on light and radius?

It's a fudge. Light dissapates inversely proportionally to the square of the distance away from the source. Double the distance and you quarter the amount of light that reaches that point. So it's assumed that close to the source is brighter than far - and then you put some completely fudged numbers in to the game because that's a lot easier than calculating squares of distances and using lookup tables.

 

[ExploderWizard]

I never understood why light has a radius in D&D. It doesn't even make, like, physical sense. What is "bright light in a 20' radius?" After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

Since we're going back to the beginning and simplifying the game, maybe we should re-examine this concept. In real life, light doesn't really have a "radius;" its ability to light a large space depends on how bright it is. So why don't we just have a few classes of light (daylight, bright light, dim light, darkness), and adjudicate it that way?

Any other ideas on light and radius?

Turn on your porchlight. Stand underneath it and try to read a book.

Then walk 50 feet away from the light and try and read something.

 

[Mishihari Lord]

It's a bit more complicated than that because our eyes adjust. Frex, on a starry night you can see reasonable well outside. If you're holding a flashlight on the same starry night you can see what the flashlight's on, but everything else is dark because your eyes have adjusted to the bright light. I'd be interested in seeing rules that covered this, but making them simple enough to use in play while being realistic enough to want to actually use would probably be a challenge.

 

[Tovec]

After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

As I understand it there was something like a 10x rule kicking around in 3e. I can't remember if it was in the PHB, DMG, a random splatbook or if it was just houseruled in but..

The rule as I remember it was that a light source is clearly visible from 10 times the distance that the light provides.

So, if it is a light source that is 20 feet, from 200 feet away you can make out the person carrying it. If it is 60 then it is 600. But maybe someone can find the actual source.

Overall I think that you have good points but I think we need to pick our battles unless you have very good and easily solution ready.

 

[Jeff Carlsen]

D&D Next has already improved this by having light sources provide full illumination up to their radius, and shadows for the same distance beyond that.

 

[Li Shenron]

What is "bright light in a 20' radius?" After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

I wonder where you got this idea from...

The way we've always play it is that it doesn't matter where the "watching" individual is, light defines only how objects are visible.

For example:
X = bright light
s = dim light / shadow
o = darkness

if you have something small with 5ft light radius, dim light twice as far, it may look like this (diagonals might be interpred different, but here it's not the point):

ooooo
ossso
osXso
ossso
ooooo

Thus everything in the "X" area is fully visible, everything in the "s" area is partially visible, everything in the "o" area is invisible... to anyone, it doesn't matter if you are looking at the object from inside the lit area yourself or from the darkness.

Obviously, this is a simplification, but seriously... any complication is most likely to make the game a boring chore.

 

[Argyle King]

I never understood why light has a radius in D&D. It doesn't even make, like, physical sense. What is "bright light in a 20' radius?" After 20 feet, does it just stop being bright? Is the light source invisible from more than 20 feet away?

Since we're going back to the beginning and simplifying the game, maybe we should re-examine this concept. In real life, light doesn't really have a "radius;" its ability to light a large space depends on how bright it is. So why don't we just have a few classes of light (daylight, bright light, dim light, darkness), and adjudicate it that way?

Any other ideas on light and radius?

I disagree that light does not have a radius. I live in a rural area. In the summer time, I have tiki torches out in my yard. I've done a few experiments with just lighting one and then carrying it around because I was curious about how accurate some of the rpgs I play were when it came to torchlight. I was surprised to find that they were more accurate than I had thought they would be.

Also, during my time with the military, I've been a part of quite a few night missions. As others have mentioned, a starry night certainly helps visibility -as do other factors, but you'd be surprised at how quickly visibility diminishes with distance. There's a reason behind why night vision was invented.

I believe there is such a thing as a radius of visibility for those who are using the light source.

On the other hand, having bright light can also be a very bad thing because it is easy to spot against the contrast of darkness. There's a reason why military flashlights have a red cover. It allows for light without the light traveling as far. I've been able to pick people out in the dark from quite a distance away simply because they were smoking a cigarette.


None of that is really relevant to whether or not D&D should be further simplified; it's just food for thought.

 

[Yora]

D&D Next has already improved this by having light sources provide full illumination up to their radius, and shadows for the same distance beyond that.

I'm quite sure it has been that way at least since 3rd Edition.

 

[ComradeGnull]

Light definitely does have a radius- take a candle into a closet and you will see all four walls; take it into a large chamber in a natural cavern, and you won't see anything out past a few feet. I do like the shadow/bright split that D&D Next has right now.

As far as spotting light from a distance- you can see very small lights from a very far distance as long as you have line of sight on them. The 10x rule probably understates the real value by a lot- in flat country in the dark you can see a small light (candle, flashlight pointed at you) from 3 miles away or more before the curvature of the earth intervenes. If you are up on a hill or mountain, you can see lights from maybe 10x that far. I would essentially say that a light source has a chance of being spotted from far away as long as the observer can acquire a line of sight to it.

Light rules (together with time rules) are one of the things that can give a dungeon crawl adventure a much more 'real' feel, and they give a lot more weight to exploration-centered classes and things like dark vision and mundane gear like hooded lanterns. If you want to scout in a pitch dark tunnel, you are going to need to think about how to observe without being observed...

I put together a table with the light sources from the play test and some quick time/light rules if anyone is interested: Exploration Rules and Quick Reference

There is a PDF at the bottom of the post if you want a permanent version. Wondering if I should include Darkvision and the Light spell in the light source table...