Liquid Light

[the Jester]

What happens if I cast light on the water (or other liquid) inside a container? Can I split the water up and have two light sources? Does only the larger concentration of water keep the spell? What if I spill the water into, say, a 15' radius puddle- does the whole thing radiate light, effectively giving me a 35' radius of bright light and another 20' of shadowy lighting?

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.

Thanks!

 

[Krelios]

What happens if I cast light on the water (or other liquid) inside a container? Can I split the water up and have two light sources? Does only the larger concentration of water keep the spell? What if I spill the water into, say, a 15' radius puddle- does the whole thing radiate light, effectively giving me a 35' radius of bright light and another 20' of shadowy lighting?

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.

Thanks!

A volume of liquid is not a single object, so it's not a valid target for the spell any more than "the atmosphere" would be a valid target to create light everywhere on the surface of a planet. If you were to rule that you could cast light on liquid, you'd have to say that a specific amount was a valid target (DM's discretion) and that even spreading the liquid out would not change the radius of light provided (it would still generate the same light from the mathematical center of the volume).

 

[the Jester]

A volume of liquid is not a single object, so it's not a valid target for the spell any more than "the atmosphere" would be a valid target to create light everywhere on the surface of a planet.

Is this explicitly stated anywhere?

A potion, flask of oil or vial of acid is a single object, isn't it?

Edit: I would say that 'the atmosphere' is more akin to 'the ocean' than to a bottle of water in this context, but I'm looking for official rules on the subject.

 

[heirodule]

So cast light on a big chunk of ice. Let it melt. Same problem

What's the answer?

 

[the Jester]

So cast light on a big chunk of ice. Let it melt. Same problem

What's the answer?

Hmm, for that matter, say you cast light on a piece of paper and then burn it. I assume, with the destruction of paper, the light is... er... gone? Is this correct?

Now, make it a stick. At what point has enough of the stick burned away for the light to vanish?

 

[werk]

The effect is immobile, but it can be cast on a movable object.

 

[RigaMortus2]

Is this explicitly stated anywhere?

A potion, flask of oil or vial of acid is a single object, isn't it?

Sure, a potion bottle is a single object, but the liquid inside is not.
The flask and vial are single objects, but the oil and acid within are not...

Can you cast Light or Darkness on a flame?

 

[Krelios]

Is this explicitly stated anywhere?

A potion, flask of oil or vial of acid is a single object, isn't it?

Edit: I would say that 'the atmosphere' is more akin to 'the ocean' than to a bottle of water in this context, but I'm looking for official rules on the subject.

Yes, but a "potion, flask of oil or vial of acid" has a defined and finite volume. Any time you cast a spell onto an object that can be damaged, then you are going to run into a similar problem. The closest source for rules on "how much damage, dispersion, melting, etc." is to use the rules for damaging objects. If you dealt enough fire damage to the stick to reduce it to 0 hp, then it no longer sheds light. Any damage prior to that has no effect on the magic in the item. Since it's impossible to exactly divide any item (at a subatomic level), the "bigger" side would logically always keep the enchantment. In game terms, this could be random for a "close enough to even" break like snapping the twig in half or melting some of the ice. Pouring liquid out so that it is no longer contained isn't that much different than burning an item to ash--I'd rule that it destroys the "object" and thus ruins the light spell.

 

[the Jester]

The flask and vial are single objects, but the oil and acid within are not...

I'm still hoping for rules citations here.

Re: pouring the liquid out destroys the object- what if the liquid has a very high surface tension and stays in a 'blob' (eg. mercury)?

Can you cast Light or Darkness on a flame?

Well, I would argue that a flame is not an object. I have a hard time arguing a potion is not an object- you can target it with a dispel magic, right? And certainly, that doesn't target the flask or vial, that targets the actual potion.

 

[ThirdWizard]

This is an old one. I don't think there has ever really been a consensus. Me, I pretend the situation can't exist, and if a player tries it, I just give them the evil eye until they retract the statement.

lalalalalalala I don't hear anything