Greetings,
I am going to have my players meet an aquatic foe. This gets me to wondering: if they are on shore and he's under a few feet of water, can they cast spells on him? Like Charm Person, Sleep, etc. Firebolt would obviously fail (well, if you use logic).
The rules seem to say you can, so long as you can see the target. But I'm not quite sure if I"m missing a rule, or perhaps mis-reading intent. What do you think?
Cheers.
I don't know of anything that clarifies this. I could see giving people under water obscurement depending on how murky or clear the water is.
In previous editions, lightning bolts hitting water effectively changed into spheres, fire based attack were greatly reduced but turned water into steam, etc.
If you want to go the physics route, water is actually pretty good at stopping many attacks. Bullets for example are only effective for a few inches.
I could also see ruling that while some spells (magic missile for example) are unaffected while others (firebolt) would only be effective down a few inches.
Regarding fire damage -- anything that is submerged in water has resistance to fire, so half damage. But I agree, firebolt probably wouldn't survive the delivery. The rules on underwater combat are brief; depending on the specific actions and spells cast by the players, you might have to make a ruling on the field, based in part on inferences that can be drawn from the scant rules that exist on underwater combat and in part based on whether it seems plausible given your understanding of your in-game universe.
I guess it depends whether you think the somatic component is something the victim must be able to hear.
Is the somatic component of the charm person used to make the magic work itself, or does the victim have to be able to hear the words?
I think the latter, myself. Not from the DMG, but from mythology. Odysseus' crew put wax in their ears to avoid the effects of the sirine song.
Barky wrote:
Their is no rule for aquatic combat in the PHB (not sure about the DMG)
Magic that require line of sight, is just this line of sight, so as long that the caster can see the target he can cast the spell no problem.
How does Magic interact with water??? it's magic and it's not covered in the PHB, so rule it as you want. Magical fire passing trought water why not IT'S MAGIC. I mean Ray of frost is powerfull enought to one shot a commoner (4HP humanoid AKA most real world human) under 6 second (single round) which mean the temperature the ray of frost is should be REALLY cold, but my DM refuse tho let me create a path of ice to overcome a river of moving water. If you want to tell your spellcaster that he's useless then make all his spell unable to penetrate water, if you want to nerf him a little then water block fire spell, but improve lightning spell, and allow force spell to pass without problems. etc...
If you use real world physic:
because of the refraction of the water I would give disavantage on any range attack. most gun bullet disintegrate as the hit the water (at the speed they go it's like doinga belly flop) but an arrow (going a lot slower and being a lot more piercing) would be shoot trought water most easier then a bullet (not feeling like doing the calculation to know how the water friction would slow down the arrow putting a treshold where the arrow do half damage, then a treshold where the arrow do no damage)
The Players handbook and the DMG has some info on Underwater combat. Nothing about casting spells. Though attacks seem to have disadvantage unless you have a swim speed, and creatures underwater get resistance to fire damage. The DMG also has a chart for how far you can see depending on the type of water. Pg 198 PHB and Pg 116 DMG.
K-Ray
EDIT: Range attacks get disadvantage at normal range and just miss beyond that.