Underwater Combat

A target that is fully immersed in water has resistance against fire damage (see Resistance and Vulnerability). In addition, any nonmagical flames on the target are extinguished.

Impaired Fighting: A swimming creature has disadvantage on Fighting tests, unless swimming doesn't cost extra movement for it (see Sea Elf and Jumping, Climbing, Swimming).

Limited Range: A ranged attack automatically fails if the projectile must travel through 6 or more squares of water to reach its target. At the GM's discretion, a projectile that has been designed or modified for aquatic use ignores this limitation.