D&D 5E Underwater Combat

[Warunsun]

Greetings folks.

Outside of what is mentioned on page 198 of the PH and page 116-117 of the DMG regarding "Underwater Combat" am I missing anything in the books? I see mention that creatures "in water have resistance to fire damage" but other than that I see no mention of casting spells underwater. It seems that the baseline assumption is that if you can breathe underwater you can cast spells underwater. If I am missing something please tell me. Thanks. My Greyhawk group just finished U1—The Sinister Secret of Saltmarsh and I am preparing for U2—Danger at Dunwater and U3—The Final Enemy.

 

[iserith]

What you see are the rules as they are - you'll have to make rulings on the rest. I would personally rule that a character under the effect of a water breathing spell can cast spells while underwater. Otherwise, they cannot, if the spell has a Verbal component.

 

[Sunseeker]

There are a few good books out there regarding underwater play, movement, currents, lighting and pressure. I suspect there might be some difficulty utilizing water-based spell components (such as holy water) underwater as well.

 

[Fralex]

Here's my logic on underwater verbal components:

-The PHB says the magic words themselves aren't the source of the spell's power; rather, the particular combination of sounds, with specific pitch and resonance, sets the threads of magic in motion.

-Therefore, to correctly pronounce verbal components, you don't need to be able to speak to other creatures, just able to produce the sounds.

-To produce the sounds, you must be able to speak without water flowing into your open mouth.

-The clearest way you could handle that is to rule that as long as air is coming out of your mouth when you speak, not enough water is coming in to garble your words immediately.

-Any effect that puts air in your lungs (like water breathing, but not the gills you gain from alter self, as gills are their own respiratory system) allows you to enunciate verbal spell components. Assume all water-breathing effects work that way unless descriptive text suggests otherwise.

-A character holding their breath can release 30 seconds' worth of air to cast one verbal spell. Naturally amphibious creatures that can speak are assumed to be capable of performing verbal components underwater unless there is good reason to believe they can't speak underwater.

-Optionally, assume any character that can speak Aquan has learned how to make clear enough sounds underwater to perform verbal components regardless of anything else.

 

[Maskah]

These ought to help

http://www.sageadvice.eu/2016/04/21/can-i-cast-underwater/

http://www.sageadvice.eu/2016/11/01...n-it-perform-the-verbal-component-for-spells/

In past editions spells casting was certainly done under water. In 5e you now have underwater monsters that can cast spells and it makes no sense for them to be unable to do so underwater. Though I think the intention is that you need the ability to breathe underwater. In any case still spell is far more useful than anyone knows.