How do you change your armor in Battlefield 3

In Battlefield 3, the player cannot change their armour because there are no alternative or unlockable amours for the player's solider. However, the player can equip the 'Flak' (squad) specialisation which will reduce explosive and shrapnel damage.

For vehicles (Main Battle Tanks / MBT and Infantry Fighting Vehicles / IFV), the player can equip the 'Reactive Armour' upgrade which will add three sets of reactive armour to the sides and rear of the vehicle which will protect the vehicle from certain weaponry. If the reactive armour is struck, it is destroyed and in turn inflicts minimal damage to the vehicle.

The reactive armour will slowly recharge after being destroyed once the vehicle has reached 100% amour. An Engineer can repair the reactive amour at a much faster rate when the base amour has been completely repaired.