Underwater Spellcasting

[jmucchiello]

Is there a rule or guideline I've missed when it comes to spellcasting underwater? Can a spell be cast underwater if you the spellcaster can breathe water (per the spell)? Do you need to make a Swim check to cast a spell with a semantic component underwater?

How does the aquatic subtype affect those answers?

Since I'm sure the standard D&D books say very little about this, can someone recommend a 3rd party underwater set of rules? (Please indicate how those rules answer the above questions when recommending said rules.)

Thanks.

 

[Vahktang]

No hard rules.
You can treat it like deafness, a percentage miss chance.
Casting a spell in a storm is like Concentration check DC 20 or something.
You can treat it like that.
A swim check for somatic component is a good idea.
Freedom of movement spell would mean no problems.
And don't forget air if your underwater.
One round per Con point if in combat.

More later,

Vahktang

 

[dcollins]

By the rules, there are simply no such disadvantages to casting underwater (either by verbal or somatic components or anything else).

The rules do dictate a modification to fire-based spells cast underwater, but that's it.