Counterstance

Counterstance is an ability available to Monks in Final Fantasy XI. This ability greatly increases their ability to Counter an attack, but it comes at an equally large drop in their defense score meaning. Functionally, this means that a monk will potentially get a counter-attack every time they are attacked, thereby increasing his own damage potential and lowering the enemy's, but the moment they start getting hit, the monk is going to lose hit points very rapidly.