Underwater Spellcasting

Talcoram Cyndar · Jun 19, 2019

Thank you all- you've given me some great answers and a lot to think about. I will probably keep it simple and let magic work normally, the exception being that fire spells do half damage.

Thanks Again-
-TC

Sword of Spirit · Jun 20, 2019

coolAlias said:
* For example, fog cannot form in water; will the spell Fog Cloud simply fail if cast underwater, or will it work because "magic"?

Depends on if you have "smart" magic or "dumb" magic (like a lot of this topic does). Smart magic would have it's own built in AI that interprets and adapts. Dumb magic would be simple tech that can't interpret. D&D magic generally requires it to be somewhat smart (as most magic systems do whether or not they realize it), but when writing rules about it they often forget that it is smart and try to give rules to govern dumb magic.

In this case, the spell would make bubbles that made the water cloudy. That's what underwater "fog" would be, and smart magic wouldn't have any problem enforcing that effect on to the weave of magic. Dumb magic would slightly slow the motion of dissolved oxygen and nitrogen atoms within 20' of a point of origin defined by the angle that the caster's finger is pointing and a distance defined in a variable in the verbal component. Underwater this would likely have negligible effect; which would likely be irrelevant since the verbal component likely would be off and ruin the casting. And of course, that assumes there are atoms in D&D Land, which is a stretch in my opinion. I strongly recommend acknowledging and using some degree of smart magic, rather than trying to technologize your magic. You don't have to make magic virtually sentient by any means, but it's a lot easier to make it effectively "know what it's doing".

TBeholder · Jun 20, 2019

Li Shenron said:
Without specific rules in 5e, spellcasting works normally underwater.

There are no penalties of any kind such as disadvantage on the spellcaster's possible attack roll or advantage to the target's saving throw, and there are no concentration checks necessary.

You can normally cast a spell that has verbal, somatic or material components underwater. Yes, also verbal component, because you can speak underwater even if you cannot breathe.

The game says nothing in terms of rules about the level of precision required by verbal/somatic components. There is some fluff text about "intricate gestures" and "specific pitch and resonance", but there is absolutely no rule saying when the circumstances make it impossible to cast, except the specific cases of being gagged or silenced for verbal, and not having a free hand for somatic. Therefore, everything else is up to the DM to house rules.

All of the above, however, could also be said about magma. :devil:

Sacrosanct · Jun 20, 2019

Li Shenron said:
Without specific rules in 5e, spellcasting works normally underwater.
.

I think this is an assumption, and a flawed one. There is no way an rpg can have a rule for everything, especially when many things can be handled by a reasonable real life comparison. We do it in games all the time. There are no rules about how many calories you need per day, or what happens if you don’t defecate, etc. There are no rules around how things work in a vacuum, or how gravity may affect things. That doesn’t mean a vacuum or gravity has no effect then. We apply real world experiences to many things in the game without a specific rule, and this is similar. Each individual DM may do it a bit differently, but to assume that because there is a lack of a specific rule that means there is no change is flawed.

Are there specific rules about what happens if you open a jar of liquid underwater? Does that mean nothing happens to the liquid in the jar when you open it underwater? Is there a specific rule about writing on parchment underwater? Does that mean you can write on parchment the same as if it were on a dry desk?

jgsugden · Jun 20, 2019

Is water an obstruction for a spell? If so, a fireball cast underwater would explode in your hands. If not, the fireball would travel through the water and explode at the original target. Wall of Water seems to imply that water is not a full obstruction, but does change how certain spells function in that Wall of Water... I'd be comfortable applying that logic in all water situations.

jasper · Jun 20, 2019

OK, Resistance to fire spells is cover in the books. Of the top of my head.
Cloud spells move slower and last less time'
Electrical spells. Longer range, additional target, Reroll 1 and 2s.
Knock is heard from 600 feet
Ice storm loses terrain effect
Wall of stone sinks 60 feet per round unless anchored
Wall of ice floats 60 feet per round unless anchored.

Tony Vargas · Jun 20, 2019

Li Shenron said:
Without specific rules in 5e,

the DM must make a ruling.

Seriously, the observation that "no rule says you can't" doesn't mean "the rules say you can."
Nor vice-versa.

It's 5e, Rulings not Rules. Even when the rules seems to say one thing, and the DM rules another, it's not a 'House Rule' it's a Ruling.

Li Shenron · Jun 21, 2019

Sacrosanct said:
I think this is an assumption, and a flawed one.

It's also an assumption, and just as flawed, that that there MUST be a penalty.

Tony Vargas said:
the DM must make a ruling.

And ruling NOT to add any house rule is perfectly legit.

What I quoted is the RAW and that is the starting point for everyone. Just because you don't like it and don't want to play without a house rule on top of it, doesn't mean everyone should do the same.

Tony Vargas · Jun 21, 2019

Li Shenron said:
And ruling NOT to add any house rule is perfectly legit.

Rulings aren't 'house rules,' they're a necessary DM function, especially in 5e, where essentially every action resolution technically includes a ruling from the DM.

What I quoted is the RAW and that is the starting point for everyone. Just because you don't like it and don't want to play without a house rule on top of it, doesn't mean everyone should do the same.

The thing about a starting point is you move on from it. The Rules of 5e are Written, as much as possible, in natural language, so they are naturally ambiguous. When the rules aren't perfectly clear & explicit, you make a ruling, deciding which plausible interpretation to use in that instance. When the rules don't cover something, you make a ruling, deciding how to resolve the action that lies outside their scope, or your game halts.

Your ruling is that a spell with verbal components can be cast under water, even by a caster who'll drown there, and will work normally. You dismiss portions of the rules as flavor text, which is exercising judgement - as a DM, in your campaign, you have every right to do that, so it's not a criticism or anything. But, it's no more or less a 'house rule' than any other DM's ruling.
If you formalize it and stick to it, it could become a house rule. Even then, as more situations come up, you'll probably need to make rulings about your own house rule, anyway, to keep your game moving.

Dausuul · Jun 21, 2019

The PHB has rules on underwater combat. The main one that is relevant to spellcasters is that a creature fully immersed in water gets automatic resistance to fire damage.

I wouldn't impose any blanket adjustments beyond that. For individual spells, I would look for a way that the spell could reasonably work as written underwater; I would only impose a penalty on the spell if it seemed absolutely absurd otherwise. If I did impose a penalty, I would tell the player when they tried to cast the spell and let them choose a different action. If they knew they were going underwater when they prepared spells that day, I might let them retroactively prepare a different one.

(Offhand, I cannot think of any spell that I would feel the need to impose a penalty on. Universal fire resistance pretty well covers it IMO.)