Saving for half damage is nice, but avoiding all the damage is nicer yet.
Prereqs: Ref +3
Benefit: On a successful Reflex save against an effect that allows a Reflex save for half damage, you may take an immediate action to move the minimum distance necessary to get out of the area of effect. If you can get clear, you take no damage from the effect. If two or more locations are equidistant, you may choose between them.
You can only evade when lightly encumbered or unencumbered, and lightly armored or unarmored. You may not evade if helpless or immobile. You may evade while flatfooted only if you have the Combat Reflexes feat.
Notes: When evading, you do not get to pick an ‘optimal’ place, you must move to the closest. If this means you get stuck in a crack in the wall or flanked between a couple of orcs with greataxes, tough. You also can’t, for example, dive across the area of effect of a fireball unless that is the only way to get clear.
Improved Evasion [Evasion]
Prereqs: Ref +7, Evasion
Benefit: If you attempt to evade and cannot, you take only half damage (as if you had made the save without the benefit of evasion). This works if you fail the save, lack an immediate action to move with, or cannot move out of the area of effect.
If helpless or immobile you cannot gain the benefit of Improved Evasion.