D&D 5E Does lightening bolt spell cause extra damage to sea creatures in water?

[Klaudius Rex]

The exact situation is that in my Dungeon of the Mad Mage game, my players come across a coven of sea hags in an underground cavern...

...and so we’re rolling initiative next weekend for battle. And they’re already discussing tactics which is cool...but one player wants to cast lightening bolt into the river, and I’m pretty sure they think that the electricity will cause damage to the hags even if they succeed in their saving throw or that the damage will be amplified because they’re in water?!

is this a thing? (I’m not much of an electrician here)...

Has anyone come across this? I especially want to hear from any Saltmarsh DMs with all that water in that setting...

And if it doesn’t work, for whatever reason, is there a way I can ‘rule of cool’ reward the player for creativity without going overboard?!

 

[Tonguez]

In real world physics the lightning would fail to penetrate very deeply and instead disapate across the surface (thats why fish dont die in every storm). A Hag swimming on the surface might get hit (10ft circle?) but diving under water would allow them to avoid damage.

 

[Shiroiken]

My simple houserule is that water generally doubles the area of effect of lightning. In the case of lightning bolt, instead of being a 5 ft wide line, it'd be 10 ft wide instead.

 

[mach1.9pants]

Basically, No. Don't try and apply real world physics to magic.

 

[Kurotowa]

In the old old days, there were entire pages of rules for how being underwater altered spell effects. Lightning Bolt, for example, would turn into a spherical AoE similar to Fireball. I believe cold spells would cause water to freeze, potentially dragging ice-bound targets towards the surface.

These are not the old days. The principles of 5e are simplicity and ease of use. Having to look up and parse all the spell alterations would only confuse your players and slow the game down, so magic is magical and just works. Don't worry about it and focus on larger concerns.

 

[Cap'n Kobold]

The exact situation is that in my Dungeon of the Mad Mage game, my players come across a coven of sea hags in an underground cavern...

...and so we’re rolling initiative next weekend for battle. And they’re already discussing tactics which is cool...but one player wants to cast lightening bolt into the river, and I’m pretty sure they think that the electricity will cause damage to the hags even if they succeed in their saving throw or that the damage will be amplified because they’re in water?!

is this a thing? (I’m not much of an electrician here)...

Has anyone come across this? I especially want to hear from any Saltmarsh DMs with all that water in that setting...

And if it doesn’t work, for whatever reason, is there a way I can ‘rule of cool’ reward the player for creativity without going overboard?!

If you want to be simulationist about it, treat lightning bolt as just electricity, but reward the player a little, I'd have the point the lightning bolt strikes the water as the centre of a 20ft radius lightening blast. (Because the water will conduct it) However I would also have anyone in that area automatically take half damage, no save. (Because the electricity prefers to conduct through the seawater water and will path around the bodies of people in it as a preference.)
So the player gets to hit more creatures, and more reliably, but will do less damage probably.

Personally I'd treat it as magic and not adjust the spell. You could make a similar argument that full plate armour should grant you resistance at least to lightning damage for instance. Its a slippery slope.

 

[Bayushi_seikuro]

I'm not sure if it's in 5e, but I think in earlier editions, a lightning bolt acted as a fireball centered at the start point of the 'bolt'.

 

[Steampunkette]

I imagine a Lightening Bolt would just make the water float bit.



But yeah. In games I generally have spells just follow their normal rules, regardless of environment. A lightning bolt goes it's full range in water, striking only what is in it's path, because it's magic in the form of lightning, rather than magic manipulating electricity that exists.

 

[IndigoTraveler]

I mean, every video game I've played with a type(ish) situation like this would usually allow lightning to do something extra. At most, you could do it like how Heat Metal treats metal and just like allow the lightning spell to roll with advantage to hit because of the water.

But I already hear the murmurs of the audience whispering their disapproval for associating. DND with video game aspects: away I go! Tuxedo Mask outta here.

 

[Flamestrike]

Its not real lightning. Its magical. It works underwater the same as it does on land.

It cant be cast by the PCs underwater unless they can breathe water though, as it has a V component.

 

[Bacon Bits]

I'm not sure if it's in 5e, but I think in earlier editions, a lightning bolt acted as a fireball centered at the start point of the 'bolt'.

Yeah I'm pretty sure that this is in the 2e PHB or DMG in the underwater combat section.

 

[MNblockhead]

"The 'kill zone' for fish is "probably not more than 30 yards away in fresh water, 10 yards in salt water, though good information is scarce[.]"

Dear Tom,When lightning hits water, how far...

www.chicagotribune.com

But as other have said, the bolt from a lightning bolt spell is not the same as natural lightning. For one, a natural lightening bolt has the diameter about the same as pencil (What happens to the fish when lightning strikes a lake?)

A pencil is 0.25 inches wide and a lightning bolt from the spell is 5 ft. wide, equal to the width of 240 natural lightning bolts.

 

[Umbran]

In real world physics the lightning would fail to penetrate very deeply and instead disapate across the surface (thats why fish dont die in every storm). A Hag swimming on the surface might get hit (10ft circle?) but diving under water would allow them to avoid damage.

Well, fish do die in lightning storms. But, the ocean is big, and there are a lot of fish in it, so we don't notice.

A full natural lightning bolt will spread when it hits the surface of salt water, and in the real world anything that's near the surface within a few tens of meters is going to have a bad day. Game lightning folks are probably smaller.

 

[jasper]

I likee the double width of LB. How about? Double the range. Or Disadvantage. OR send $20 Amazon dollars to Jasper to get a Starbucks. Must have cough ee.

 

[Weiley31]

It's a moment like this where you ask yourself that very important question: To Rule of Cool or not to Rule of Cool.

Rule of Cool dictates that Lightning and Water don't mix very well ala the Trope of what usually happens when Lightning and Water get introduced to each other. As to whether the Hags see that coming a mile away, well that depends on whether or not the coven gets along with each other. If they are too busy arguing with each other about some "usual" petty squabble that they bicker about, then that's a distraction that could help out.

To me that would probably be the only part that is the questioning or what. I'm more leaning towards Rule of Cool with the Lightning/Water though.

 

[Crimson Longinus]

I would definitely let it do something extra. Increased area and/or disadvantage to saves would work. This is the players engaging with the fiction, and trying to act smartly, and this is a good thing. 'It's magic, it just does what the rules say and nothing more' is a boring answer and makes the magic feel more gamey and less real.

 

[Salthorae]

I like the dis to saves and also the double width ideas, both of them make it more thematically cool and also a little extra.

But ... these hags aren't dumb and I'm sure they've thought about lightning or whatever. They're ancient magical creatures after all.

 

[aco175]

Depends on how far you want to go with modifying spells. Would a heat metal spell be negated if the target jumped into the water? What would happen to a fireball cast under water? I'm thinking that most all the elemental spells would be modified somewhat in other environments. You could just keep spells the same as the book under 'magic', or you allow the player to change them based on the situation.

I'm not sure which is better. I would want to reward clever players with something like the lightning in the water idea. I would also like to keep things simple and have only one way that things work. It may come down to the just the way the rules work and things like being able to knock prone a snake.

 

[Tales and Chronicles]

In this very specific case I'd just go for the easiest solution that comes with de desired visual:

Use the spell description of Chain Lightning, but use the damage of Lightning Bolt.

 

[BlivetWidget]

Would a heat metal spell be negated if the target jumped into the water? What would happen to a fireball cast under water?

PHB198: "Creatures and objects that are fully immersed in water have resistance to fire damage."

This is the only rule with any relevance to magic and water. Anything else is a house rule.