Your mastery of water magic blocks an incoming attack.
Prerequisite(s): Ability to cast 2nd-level spells, Elemental Focus (Water).
BENEFIT
As long as you have an elemental (water) spell of 2nd level or higher in your known spells, have at least 2 MP in your MP pool, and a reasonable amount of water for your size, adjacent to you or on you, you can use a move action to raise a water shield. This shield remains until your next round after which it disappears. If, before your next round, you are targeted by an attack that requires an attack roll, that attack suffers a -2 and deals only half the damage it would deal (unless it’s specifically made to hit through water or a lightning spell, but a simple piercing weapon doesn’t benefit from this). After that the shield immediately disappears.
If you are targeted by an fire or ice effect (whether it’s an attack or something else), such as a red dragon’s fire breath, a sword with the frost enchantment or a fire spell, the effect doesn’t deal any elemental damage, leaving you unharmed, but consuming the shield. A non-elemental effect is unaffected by this property, while a lightning effect deals 1 extra damage per damage die and you have a -2 to the saving throw against it. As a secondary benefit, you gain a +1 competence bonus to your caster level when casting elemental (water) spells.
Special: If you have the Hydromancy feat, you can create the shield at a moment notice, with a swift action during your turn, or with an immediate action in response to an attack. You may still do it only once per round though.