Immune: constructs, undead

The character takes a –2 penalty on all attack rolls, weapon damage rolls, saving throws, skill checks, and ability checks.

Marius, Scholai Armsmaster Says: The sickened condition can be created by anyone through the dirty trick combat maneuver. Unlike most other conditions, sickening actually causes a penalty to damage rolls, making it an effective way to limit the effectiveness of foes with multiple attacks. Since sickening causes a -2 penalty to saving throws, dirty fighting warriors can set their spellcasters up for success by breaking their enemy’s resolve before the magic starts flying.