The Drive Gauge.
The Drive Gauge is a bar (like that of HP and MP) which is introduced in Kingdom Hearts II and appears above the MP gauge. The use of Drive Forms and Summons depletes the gauge, while replenishing the gauge is done by dealing damage to enemies, picking up Drive Orbs, or using the Drive Recovery or High Drive Recovery items.
When a Drive Form or Summon is triggered, the Drive Gauge's function changes. The Drive Gauge becomes grey and the gauge starts depleting to indicate the time remaining for the Form or Summon's activation. The more damage is dealt, the faster the gauge depletes. When the gauge hits zero, Sora's form or summon deactivates.
In Kingdom Hearts II, the Drive Gauge can be upgraded to a maximum capacity of 7. Upgrades are awarded by defeating certain bosses. In Kingdom Hearts II Final Mix, this number is increased to 9 and the awarding battles are slightly changed.
Drive Gauge Upgrade Points[]
Kingdom Hearts II[]

Drive Gauge while in a Form.
- Defeat Barbossa in Port Royal.
- Defeat the Hostile Program in Space Paranoids.
- Defeat Saïx in The World That Never Was. In Kingdom Hearts II Final Mix, this upgrade is removed and instead awards 5 HP.
- Defeat Sephiroth in Radiant Garden.
Kingdom Hearts II Final Mix additions[]
- Defeat Marluxia's Absent Silhouette.
- Defeat Xemnas's final battle.
- Defeat the Lingering Will.
Abilities that affect the Drive Gauge[]

Drive Gauge while using a Summon.
- Damage Drive - The Drive Gauge is refilled when damage is taken.
- Drive Boost - Drive Gauge restoration is increased during MP Charge.
- Form Boost - The Form Gauge depletes at 80% normal speed.
- Summon Boost - The Summon Gauge depletes at 80% normal speed.