This skill hones athletic agility and balance. You are trained in a variety of fast and flexible moves involving both your feet and hands. This skill also covers gymnastics (movement over difficult terrain) and all inherent motions.
Similar to the Armour skill, the GM may decide to cancel penalties in combat related to awkwardness. Whereas doing a backflip can be dangerous, one sufficiently skilled in Acrobatics has no penalty to perform the maneuver. A good rule is every 3 or 4 levels in this skill removes one such combat penalty.
Example: An opponent comes from behind and you're face-down in quicksand. You want to dodge and encircle the opponent. The GM figures this is all worth at least three penalties (the sand, the encircling, attacking blind.) Your skill is level 8. The GM decides to cancel two penalties, but that Acrobatics does not help fighting an unseen opponent.