Health



Health is the hit point total that governs the survivability of the Survivors in Left 4 Dead. All Survivors begin with a total of 100 health at the start of every campaign, when they'll complete a chapter their health will be saved for the next chapter, in Versus the Survivors will always start at 100 health at any chapter.

As the Survivors receive damage from the Infected, falling from high places, enivornmental harzards, friendly fire or even glitches, their health decreases. When a Survivor's health is below 40, they begin limping and their movement speed is decreased. As their health level continues to drop, their limp increases in severity and their speed continues to decrease. By the time they reach 1 health point, their limp is extreme and their movement rate is significantly reduced.

Once their health is depleted, they will count as incapacitated and will fall to the ground helplessly, but still being able to use their pistols with a total of 300 health and must be helped up by teammates before bleeding out to death. In Left 4 Dead 2, two or more Survivors can help an incapacitated comrade at once, cutting down the time it takes to get them back on their feet. When reaching a total of 3 incapacitates without healing with a First-aid kit a single time in the whole 3 row the player's view will become blurred and colorless, and items will glow red, sound will be harder to understand along with a steady pulse beating. Unless healed by that time, the next incapacitate will be count as death.

Upon death, the deceased Survivor will drop all of their weapons and items and turn into a ragdoll. Dying does not mean you lost the game yet, you will have to wait 1 minute until transferred to the nearby rescue closet and then rescued by another Survivor. In Versus mode the Survivor cannot come back to life inside rescue closets and will have to wait until the Survivors are overhauled, finished the chapter, restarted the round, or wrote "respawn" in console while "sv_cheats" is on.

However, there are several other ways to lose the game related to death:
 * Being fully overcome by the Infected, leaving the group unable to play.
 * However, if one Survivor is incapacitated and another is pinned by a Smoker, Hunter, or a Charger the incapacitated Survivor can still save the other Survivor by shooting and it won't count as a loss.
 * Dying in Single-player mode, leaving the other AI-controlled bots to play alone.
 * Dying in Campaign or Versus mode with all the other Survivor human-controlled players, leaving only bots alive.

Healing
Health can be restored in various ways:
 * Using a first-aid kit will restore 80% of the player's current health.
 * Using pain pills will restore temporary 50 health, which will slowly decrease to normal health as time passes.
 * Using a adrenaline injector will restore temporary 25 Health. They also make you immune to melee fatigue and the horde's slowing melee attacks for a short period of time.
 * Being incapacitated and revived will automatically grant the Survivor 30 Health, but this should not be used unless the player is below 30 Health already and are not on their last incapacitation.
 * Being rescued from a rescue closet will grant the Survivor 50 Health and tier 1 weapons. The type of weapon depends on what the Survivor was carrying when they were killed. For instance, if the Survivor had an assault rifle, that Survivor will get a submachine gun when they are rescued.