MP, standing for Mana Points, is the player's overall mana. This can be partially restored by using potions or fully restored by visiting Twilly or logging out. If the MP count reaches 0, then the player will be unable to cast spells or use any misc. items or skills that demand MP, requiring the use of a Mana Potion if in battle. Some quests reduce the amount of MP the character has by a certain number as a penalty. Occasionally, the MP "pool" amount can reach negative numbers through certain events, and when this occurs, it is treated the same as if the player had no MP.
Mana may be restored with methods in battle aside from potions as in a weapon, for example, in the Blood Blade, and in addition, it also increases the amount of HP a player has. Other weapons have the same ability, but some may function better than others. Other sources of mana regeneration in battle include Sila's Staff and its lower-leveled Naga's Staff, the Glacial Short Staff, the Lightning Rod, and the level eight Wizard skill Dharana. Mages and Wizards, characters who have focused on using spells and magic weapons in battle, will benefit greatly from this as mana is vital for their offense.