Liquid Light

[the Jester]

Another related question...

If I cast light on an item and then disassemble it (eg. I cast it on my armor and then pull off the breastplate, epaulets, etc), what happens to the light? Again, is it on the biggest piece? Or is the armor "destroyed" and the light goes away?

Am I just being difficult here or what?

 

[dcollins]

It's easy enough to rule on these issues- I'm curious as to whether these issues are addressed anywhere in the RAW, FAQ, a Sage Advice, etc.

Not addressed in any official source.

My ruling would be "sticks on largest part of broken material, if severely broken then spell goes away".

 

[werk]

It's effective for a 20' radius, and you're not going to change that. It doesn't make the target object glow or shed light, it just sets the object as the center of the spread.

So the real question you are asking here is, when light is cast on an object, how do you determine exactly where the center is on an object? And I think that is up to the DM.

I guess I'm missing why this is a problem.

 

[DreamChaser]

the basic question in my mind is should a vague area of the rules allow a 0 level spell to go beyond its own description, which is to say illuminating a 20 foot radius sphere?

the basic answer to this question is "no" as far as I'm concerned.

I would rule the the effect is targeted on the "center" of the object upon which it is cast. If, at any time, the object is altered in such a way that its "center" no longer exists or applies in any meaniful way (for example, an urn being shattered) then the spell ends. Why? Because the target object no longer exists. Instead of having an urn (one object) you now have several (urn fragments). If on the other hand, the alteration is relatively minor (say a section of the urn being chipped away) you still have an urn so the urn still glows. The small shard of urn does not, however, because the spell was not cast on a small shard of urn.

Water would work the same way. If you target the spell on a pool of water (assuming you're DM consideres a pool an object), then the water glows. If you take a tiny portion of the water out, the pool continues to glow but the removed water does not.

DC

 

[RigaMortus2]

What happens if you cast Light on a 10 foot pole? Or a Reach Weapon? Or a Whip (which I beleive has a 15 foot reach IIRC)... When you whip someone, would the radius become larger than 20 feet?

 

[Infiniti2000]

If you cast light on an object, that object essentially becomes a magic item, albeit temporary. Agreed? Therefore, consider any radical deformations as essentially a destruction of that magical item and therefore "all its magical power is lost." If you cast light on the water inside a mug and then spill the water out of the mug, I would consider the water 'destroyed' and the light spell lost. This is far easier to grasp with the example of a piece of paper that is burned.

 

[the Jester]

OK, this entire thread is academic; none of this has actually come up, but I got to thinking about it, and look what happened!

Now, as to the 20' radius regardless of what it's cast on, does anyone run it that way?

For instance, if I cast light on my tie, isn't the general consensus on how much light is shed depicted like this (L=light area, C=character):

LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLCLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL

That's how we've always run it; but looking at it again, it's actually a 22.5' radius (because of the C space).

Technically, if the radius is only 20', you need to shave off one square off of each direction:

LLLLLLLL
LLLLLLLL
LLLLLLLL
LLLLLLLL
LLLLCLLL
LLLLLLLL
LLLLLLLL
LLLLLLLL

Anyone actually treat it this way? How do you decide which 'edge' you trim off?

Apparently, light is full of interesting issues. See what happens when I'm trying to distract myself??

 

[ThirdWizard]

Without looking up anything and throwing out my wild assumptions based on other spells with an area of effect (but for the life of me I can't remember how eminations work) wouldn't you center the effect of the light on a crosshair on the board, so that it went 20ft in all directions from there. It does however, leave the awkward situation of your tie seeming to be not on your body but far in the corner of one of your own squares.

Nothing's perfect.

 

[wuyanei]

I've always ruled that the light is centered on a 'single point' on or within the object. So if you cast light on a pole then cut the pole, the light is centered on a single point in or on one of the two halves (just let the player declare which half -- you still only have one source of light).

In the case of a bottle of water, the (single) center point of the light spell is just somewhere within the puddle of water (determine randomly if the precise location is an issue). In any case, you still only have one source of light.

 

[Krelios]

OK, this entire thread is academic; none of this has actually come up, but I got to thinking about it, and look what happened!

Now, as to the 20' radius regardless of what it's cast on, does anyone run it that way?

For instance, if I cast light on my tie, isn't the general consensus on how much light is shed depicted like this (L=light area, C=character):

LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLCLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL
LLLLLLLLL

That's how we've always run it; but looking at it again, it's actually a 22.5' radius (because of the C space).

Technically, if the radius is only 20', you need to shave off one square off of each direction:

LLLLLLLL
LLLLLLLL
LLLLLLLL
LLLLLLLL
LLLLCLLL
LLLLLLLL
LLLLLLLL
LLLLLLLL

Anyone actually treat it this way? How do you decide which 'edge' you trim off?

Apparently, light is full of interesting issues. See what happens when I'm trying to distract myself??

No, a 20' radius is defined by the game. It's not actually a 20' circle, it is a radius that extends out 4 squares in every direction from a corner the caster designates. If the spell is cast on an object, you can pick which corner of the square that object occupies to determine the center point. Look in the PHB/DMG. There are templates in the back that show you different spell radii on a grid. Basically, all of your questions could be answered by simply reading the rules and occassionally making a judgement call based on them.