Ragnarok Online/Skills/Berserk

Berserk

 * Passive
 * Requirements: Job Lv 30
 * Quest Skill

When your current HP is reduced to less than 25% of your maximum HP, your character will automatically enter a state identical to if Provoke Level 10 were used on your character. Your ATK will increase by 32%, but your DEF will decrease by 55%. This status lasts until your current HP rises above 25% of your maximum HP or it is nullified by some other means, such as a skill or an item.

Acquiring this skill requires completing a special quest, which is described in detail on the Skill Quests: Swordman page.