Parry (skill)

Parry:

Usage: automatic

Blocking incoming attacks with a shield, weapons or anything else in one of
your wield positions is often referred to as parrying. Parrying is a
technique used by master swordsmen which follows along the idea that if you
are more dextrous than your opponent you will be able to get your weapon in
the way of their weapon, faster than they can get their weapon to your body.
Parrying attacks requires a shield, weapon, or something in one of your
wield positions. To parry an incoming attack, the skill level of parry is
considered, as well as your dexterity versus your opponent's dexterity.

It has been rumored that this ability improves in power for users who exceed 
100% ability mastery.