Parry Ability skill

The Parry skill is what dictates your character's ability to fend off an incoming melee attack with your weapon in hand. Your parry is affected by your reflexes and the current weapon you have in hand.

Attempting to parry with a poorly balanced weapon or a weapon in which you have few ranks in will be less successful than parrying with a well balanced weapon that you have many ranks in.

It should be noted that parrying does teach specific weapon skills. Example: If I were to parry with a longsword I would also gain experience in the Heavy Edged skill as well as Parry. One other interesting note is that both Paladins and Barbarians can parry ranged weapons so long as they are close enough to the shooter. This is done by using the sword to deflect the aim of the ranged weapon.