MP Recovery
In Kingdom Hearts, once Sora was given his first magic spell from Donald in Traverse Town, he gains the ability to cast magic from the Magic or Shortcut menus. All magic, techniques, and summons consume a certain number of MP (with each segment in the MP Bar representing one point), and when the MP bar has been completely exhausted, no more spells can be cast.
However, as Sora uses physical attacks or, with a certain ability equipped, take damage, a small orange bar along the outer rim of the MP bar rises. The extra energy exerted by attacks is absorbed and turned into a subunit of MP known as Charge, represented by the aforementioned orange bar. Each time the Charge Gauge reaches a certain point beyond Sora's current MP, it is converted into one new point of MP, which is automatically added to Sora's MP Bar, where the Charge Gauge will start over from the bottom of the MP Bar.
Some players, often those who focus highly on physical attacks, will depend solely on the use of the Charge Gauge to gain back lost MP, leaving Item slots open for Potions and other HP restoring items. However, it should be mentioned that the more MP Sora has, the longer it takes the Charge Gauge to convert into one point of MP, since the gauge must reach one point higher than the current MP total.
Charge can be gained by picking up the clear MP Balls dropped as prizes from enemies, attacking with physical attacks, or by sustaining damage while the "MP Rage" Ability is equipped (Cost 2 AP). The more damage that is dealt (or taken), the more Charge will be gained.
Some spells (like Fire) consume Charge before they consume MP, making them less costly to use. Some fans of the series were disappointed at the loss of the Charge Gauge for the inclusion of Kingdom Hearts II's MP Recharge, which slowly recharges to full when all MP has been exhausted.
