How I Would Rule: Lightning Bolt In Water

By David Claxton

Pictire of fireball

There are countless spells throughout the games of Dungeons and Dragons 5E and Pathfinder 2nd Edition. Magic affects the world in many ways but what happens when a magical effect brings up situations where the laws of physics could cause different things to happen? There are oftentimes that physics questions will be asked by players. One of those questions that comes up often in my games is about lightning bolts. While I am going to use lightning bolts as the spell for this article feel free to use it as a guide in your games for any spells that use electricity.

The main question that comes up is: If a creature is in water does lightning affect it differently than on dry land?


DM:  You stand before a great cliff face. It rises hundreds of feet into the air. At the base of the cliff is a small cave. The cave’s entrance is dark and appears to turn to the right blocking your darkvision from seeing deeper within. The wind blows a chill deep within as snowflakes start to fall. The weather is getting colder, the incoming clouds speak of the seasons first snow fall. What do you do?

Goran The Great: I turn to the party, “We should seek shelter for the night in that cave. I would hate to be out in the cold after dark, those clouds look like they are going to bring us a significant snowfall.

The party nods their agreement, and they approach the cave.

DM: As you enter the cave you immediately start hearing dripping water. Entering just the mouth of the cave the wind dies down to a small breeze.

Shriak the Sneak: I stealth and go around the corner. “Everyone stay here let me scout ahead.”

DM: Shirak you move around the corner, and you see a large cavern with the ceiling raising 40 feet above you. Giant stalactites jut down toward a large pool of water 100 feet in diameter.  The thing that really catches your attention is the movement in the water. The pool appears to have 20 humanoid froglike creatures swimming around. Judging by the skeletal remains around the outside of the pool these creatures will not take kindly to your presence.

Shirak the Sneak: I go back to the part and tell them what I saw.

Toran the Wizard: I have an idea; I will cast lightning bolt into the pool to fry them all before they even know we are here.

The party agrees to the wizard’s plan of action. But will a lightning bolt do what the wizard wants it to?

Dungeons and Dragons 5E

The text of the lightening bolt spell offers us very little about whether there are any extra effects when it comes to water. You can read the text HERE.

The parts of the spell that interest me the most is that it is five foot wide and that it is capable of damaging anything not held or worn.  This tells me that the effect can affect anything within the 100-foot line not just creatures. In older editions of Dungeons and Dragons the spell would reflect off surfaces until the 100-foot line was complete. It was possible that a creature could end up in multiple lines of the spell and must make multiple saves. This is not in 5E so we have to either use rules as written (RAW) and not allow any further special effects or look elsewhere for our ruling.

One of my favorite monsters for underwater combat in 5E is the Giant Electric Eel. It can shock creatures that are close to it (within 5 feet) OR it can damage each creature within 15 feet of it in a body of water. So, if someone was to grab the eel, they would get shocked. If it is underwater it can shock up to 15 feet away anyone around it. I would use this as my inspiration for making a home ruling.

How I would rule for Dungeons and Dragons 5E:

The lightning bolt would affect any creature in the normal 5-foot line but instead of 5 feet I would make it a 15-foot-wide line within the water only. I would allow saves as normal.

Note: Other spells with electricity might hurt something further away but I would never do “more damage” in underwater. Spells like shocking grasp I would give splash damage. While splash damage does not exist in 5E Jeremy Crawford has often defined different effects as splash damage. Such as with Lightning Arrow READ TWEET HERE. I would allow the electricity to damage the creature within 5 feet (friend or foe).  

Pathfinder 2E:

We get less information about Lightning Bolt with Pathfinder 2E. You can read the text of the spell HERE. However, even though the text is brief we can discern 2 things. 1. The lightning starts from your hand and goes 120 feet. The line of effect rules FOUND HERE tells us that creatures within that line 5-foot wide are affected.  While the spell does not appear to damage anything else in that line besides creatures, I feel that it should have the same effect as in 5E and damage any non-held or worn items as well. PLEASE NOTE: The Lightning Bolt spell text says it has a range of 120 feet. The line effect says that Lightning Bolt only goes 60 feet. This is something I have been wondering about myself, but I always err on using spell text only when it comes to this.

How I would rule for Pathfinder 2E:

My ruling would not change from 5E. There are hazards listed that use electricity under water such as the one in “Pathfinder 2nd Adventure Path #170 Spoken on the Song Wind” that send electricity through the water and damage everything in that area. However, since the description says that it triggers a burst this uses different rules. You can read that hazard HERE. What it does tell me is that water does influence electricity. So I would rule the same is in 5E and give it a 15 foot line instead of the normal 5 foot line.

 My final note:

It is often said across the web that using a fireball like burst from the target would work very well in determining damage from Lightning Bolt. If this is what you decide then that is great. For me, since it is a line that hurts anything in the line, I feel that the entire line of electricity should broaden rather than just at the final target of the spell.

What would you rule? Leave your comments below.