Health

Health in Battlefield games is a measure of a soldier's life in hit points (HP). So long as a player has health, they can take action as normal. Various sources of healing (usually provided by the Medic class) allow a player to regain health.

A similar game mechanic is used for vehicles, with a gauge representing how much more damage they can receive before being destroyed. This is generally referred to as "armor", though actual armor protection remains the same. A wrench or repair tool can be used to restore a vehicle's health.

A player's (and vehicle's) health usually appears in first-person view HUD, and can also be seen by teammates.

Weak points
In general, infantry receive more damage to the torso, neck, and head. In many games, a headshot from a sniper rifle is a one-hit kill, though medics can (inexplicably) revive headshot victims. Body armor may reduce the damage a player receives.

Vehicles also have weak points where AV weaponry may deal additional damage. Certain vehicles that are normally resistant to small arms fire may have weak points where such weapons can inflict damage.

Alive
The player has at least one hit point. A heartbeat sound typically plays when the player has less than 10% health, to remind the player to find a source of healing. In most games, players do not otherwise recover health, Also the screen looses a little color and goes into black and white after the player heals from 2% or higher they will regain their Vision and the heartbeat goes back to normal rhythm.

Critically wounded
On games featuring the defibrillator, a player is considered critically wounded for 15 seconds after losing all of their HP. A downed soldier can call for a medic, and very little else. If a medic does not revive the downed soldier in time, the soldier dies and is considered killed.

Until those 15 seconds has passed, the player keeps their reinforcement ticket, if used by the game mode.

Soldiers killed by explosions or vehicle collisions die instantly.

Killed
The player has expired or committed suicide, and has been removed from the battlefield. First-player view is disabled, and the player only sees the surroundings near where they died.

At this point, a spawn screen appears, allowing the player to select a spawn point and respawn if possible. The player can also use their loadout screen, text chat or leave the game.

On game modes where reinforcement tickets are used, being killed expends a ticket.

In certain games, a killcam shows who killed the player, allowing them to plan ahead for their next respawn.

Operational
The vehicle has enough hit points that it isn't on fire.

Disabled
Vehicle movement, weaponry, or other functions are unavailable for various reasons. Low-flying air vehicles that are disabled are likely to crash to the ground. Most Battlefield games allow limited use of a vehicle until it is actually destroyed.

In Battlefield 2142, EMP weaponry can lock down vehicle and turret movement.

In Battlefield 3, vehicles that are reduced to a fixed amount of health (depends on the vehicle) have compromised movement and control. They also catch fire and will degrade until destroyed, unless repaired by an Engineer or specializations such as Extinguisher. The disabled vehicle must be fully repaired, otherwise it will soon catch fire again.

On fire
Vehicles or emplacements with very low health (about 20%) will catch fire, eventually being destroyed and killing any occupants. The health loss caused by fire is usually more than can be regained using a wrench or repair tool. A klaxon will sound to urge occupants to bail out. Most or all vehicle functions are still available up to the point where the vehicle is destroyed. Air vehicles may have a higher tolerance for fire, losing health at a lower threshold.

In Battlefield 2142, the Dystek Repair Tool 2.0 Upgrade can provide enough additional repair rate to spare a vehicle from fire.

Destroyed
The vehicle has lost all hit points, and explodes. Any occupants are killed, and bystanders can be harmed by the explosion.

The destroyed vehicle's hull—or parts of it—can hurt or crush infantry, and obstruct the movement of other vehicles.

Spectating
Players that do not (or cannot) respawn can continue spectating. Certain games or servers may restrict what a spectating player can see, or may return the player to the spawn screen after some time.

Players who join mid-round are also considered spectating.

Battlefield 2
Battlefield 2 introduces defibrillators and the "critically wounded" state.

Different types of body armor are also featured, allowing the player to choose between a health or mobility advantage.

Battlefield 2142
Various gadgets in Battlefield 2142 allow players to see an enemy's health.

Bad Company
The health is still non-regenerative, but can be manually regenerated through the use of an Auto Injector or a Medkit. Vehicles are repaired with the use of a Repair Tool.

Battlefield Heroes
In Battlefield Heroes, the various classes have different amounts of health. Hit indicators also show how many points of damage an attack has inflicted.

Abilities can be used to restore health, improve resilience, or increase damage. Bandages can be used by a player to restore their own health.

Wrenches can only be used by drivers/pilots for repair of their own vehicle.

Battlefield 1943
Battlefield 1943 is the first Battlefield game to introduce regenerative health, which is done by staying away from enemy fire until the player is in full health again. Vehicles are still repaired through the use of a wrench, though fighter aircraft like the F4U Corsair and A6M Zero can have their health replenished by flying over an aircraft carrier or runway that belongs to the pilot's team.

Bad Company 2
Bad Company 2 also uses health regeneration, which is faster in singleplayer than in multiplayer. In multiplayer, the medkit speeds up health regeneration and with the Medkit Improved Heal specialization, health regeneration speed is doubled, making a player go back into the action much faster. Vehicles are repaired in the same fashion as the first Bad Company with the repair tool.

Battlefield 3
Health regeneration returns in Battlefield 3 allowing players and vehicles to recover health, albeit at a much slower rate than with a medkit or blowtorch.

The new suppressive fire feature negates regeneration.