Reactive armour

Reactive armour is a type of vehicle armour used for protecting vehicles, especially modern tanks, against anti-vehicle armour-piercing munitions.

Reactive armour is most effective against shaped charges and hardened kinetic energy penetrators. When a shaped charge strikes the upper plate of the armour, it detonates the inner explosive, releasing blunt damage that the tank can absorb.

The most common type is explosive reactive armour (ERA), but variants include self-limiting explosive reactive armour (SLERA), non-energetic reactive armour (NERA), non-explosive reactive armour (NxRA), and electric armour. NERA and NxRA modules can withstand multiple hits, unlike ERA and SLERA.

Reactive armour can be defeated with multiple hits in the same place, often achieved with tandem-charge weapons, which fire two or more shaped charges in rapid succession.