They are often hidden in difficult areas to reach. There is one of each droid in every level, you can pickup one droid at a time, and you can loose droids if certain ammounts of damage is attained in one go, however you can pick these back up. Look for the ammo regenerator area in every arena to replenish your attack power (red colored). There is a unique special attack on the fourth charge which varies depending on the vehicle. There is a unique special attack on the fourth charge. If you charge your weapon to the second level, you will fire for example, two missiles. Standard attack consists of firing your weapon (uncharged). Any weapon can be charged up to a fourth level.
If your health is depleted your vehicle is destroyed and you lose the battle. The hull cannot be repaired unless a R2-D2 droid is picked up. Look for the shield regenerator area in every arena to replenish your shield power (blue colored). There are various forms of Health, Ammo and Power, which balances differently for each character:
