Undertow
You create an area of water 20 feet deep. The DC for Athletics checks to Swim in the area is equal to your spell DC. A creature that starts its turn in the area must attempt a Fortitude save.
Critical Success The creature is unaffected.
Success The creature takes 2d6 bludgeoning damage.
Failure The creature takes 4d6 bludgeoning damage and takes a –2 circumstance penalty to Athletics checks to Swim and a –10-foot circumstance penalty to its swim Speed, if it has one, until it leaves the area.
Critical Failure As failure, and the creature is pulled 10 feet down.
Traits
An action with this trait requires a degree of mental concentration and discipline.
An ability with this trait can take a character completely out of the fight or even kill them, and it's harder to use on a more powerful character. If a spell has the incapacitation trait, any creature of more than twice the spell's rank treats the result of their check to prevent being incapacitated by the spell as one degree of success better, or the result of any check the spellcaster made to incapacitate them as one degree of success worse. If any other effect has the incapacitation trait, a creature of higher level than the item, creature, or hazard generating the effect gains the same benefits.
Effects with the water trait either manipulate or conjure water. Those that manipulate water have no effect in an area without water. Creatures with this trait consist primarily of water or have a connection to magical water.