A Mobility Kill (or M-kill) in armored warfare is a vehicle that is immobilized, or the act of immobilizing such a target. Tanks and other armored fighting vehicles can be immobilized by damage to their engines, tracks, or running gear. Because of the mobile nature of modern warfare, such a vehicle is often effectively useless on the battlefield, but it may be repaired and brought back into action quickly.
Mobility Kills (and Mobility Hits) were introduced in Battlefield 4. They may also be referred to as "Critical Damage" or "Critical Hit".
While the concept is somewhat similar to disabling vehicles, it differs in that while disabling catches a vehicle on fire, causing it to burn out, mobility hits impede the functionality of the vehicle, not causing its health to drain. All vehicles with a HUD will alert the driver (and possibly gunner) to mobility damage.
Mobility damage occurs when a certain threshold of damage is done with a single attack, causing shock to the vehicle's systems (for example, 30% to cause a Mobility Hit on a tank, or 40% for a Mobility Kill, not counting reactive armor).
Some specializations for vehicles can partially counteract the effects. Maintenance makes recovery faster, Gyro Stabilizer helps maintain control, while Reactive Armor and Smokescreen protect against loss of mobility.
There are various types of mobility hits and kills:
Mobility hits occurs when a ground vehicle suffers at least 30% damage (40% with Reactive Armor), 20% for most aircraft, and 13% for transport choppers. These will cause the vehicle to have reduced speed and mobility for 5-10 seconds.
- The gun turret of a Tank, IFV, or Anti-Air vehicle is struck, causing it to turn very slowly, and causing static on the occupants' camera view.
- The propulsion and steering of a vehicle is struck, causing it to move more slowly and with less control. Mobility is not completely lost.
- The rotor systems of a helicopter are struck, causing it to lose some power and become difficult to control. This may lead to a low-flying helicopter crashing into an obstacle, or overturning. The Gyro Stabilizer helps to alleviate this effect.
- The wings of a jet are struck, causing loss of steering and altitude control. The Gyro Stabilizer lessens the effect.
A vehicle is completely immobilized (hence mobility-killed), making it impossible for the driver to move the vehicle. On heavy vehicles, this is normally achieved by hitting the treads/wheels or the back end with considerable damage, since the sides and back have less armor plating. A straight angle with maximum damage is usually required to achieve enough damage.
Mobility Kills occur at 40% (no reactive armor) 45% (reactive armor) damage for ground vehicles.
If an armored vehicle or car is mobility-killed, it is impossible to move at any speed. The vehicle's display will alert "IMMOBILIZED", "CRITICAL DAMAGE". The turret will generally still be operable. After about ten seconds, the vehicle will eventually recover, progress being indicated on its display screen. An Engineer may repair the vehicle to recover it faster.
If a helicopter is mobility-killed, its main rotor is disabled, causing the helicopter to fall and lose control, which may cause it to overturn. The display will alert "ROTOR OFFLINE", "CRITICAL DAMAGE".
If it does not recover, the helicopter will often crash, likely destroying it. This can be especially dangerous if flying low or near tall buildings. The vehicle will recover in 5-10 seconds, but an Engineer repairing it makes this much faster.