Healing items

"First to aid, last to die."

- Bill "Hope you don't mind, I'm gonna... take this First Aid kit here."

- Ellis

Healing items are those used to restore lost health, be it a temporary health boost or a permanent restoration. They can be found in ambulances, safe rooms, or randomly throughout levels, but are most often found inside of first aid stations. First aid stations may contain up to four bottles of pain pills, but they may contain first aid kits instead, depending on how well the Survivors are doing, the difficulty level, and the gameplay mode. First aid stations found in safe rooms and at finales always contain first aid kits.

First Aid Kit
"Can everyone stop a sec? I'm gonna heal!"

- Zoey "Now don't waste this by getting pounced on or something."

- Nick

The First Aid Kit, colloquially known as a med kit or health pack, is used to heal damage the Survivors take during a campaign. When carried by Survivors, it is held on like a backpack with no visible straps holding it.

First Aid Kits are vital to survival, as they bring a player from an incredibly wounded to fully healed state. When the player is in a black-and-white situation (where they are killed if their health reaches 0), using a first aid kit will restore a player's "chances" and bring them out of that state.

First Aid Kits can always be found inside of safe rooms, and during the finale of a campaign. They can also be found in first aid stations and in random places anywhere else throughout the campaign, though this is very rare. There are odd occasions where the Survivors can encounter fixed locations for First Aid kits that permanently spawn outside the safe room such as in The Parish campaign in the chapter The Park where two kits can be found under a tent, and randomly in the CEDA trailer leading to the Crescendo.

In Versus mode, if the players heal each other, the Director will spawn more health kits within the map. Keep in mind if you are the first team to play as the Survivors, whatever health kits you caused the Director to spawn will also be available to the other team when it's their turn. This could be a hazard as the Infected team could use it to their advantage for when they become the Survivors and learn the locations of the spawned health kits when dead or as a ghost in spawn mode.

In Left 4 Dead 2, the player has the choice to pick up a Defibrillator or Ammo Upgrades instead, which can be used to revive dead teammates or ignite/explode the Infected with special ammunition.

First Aid Kits can randomly be spawned by the Director when Survivors are obviously hurting and low on/have no healing items. They can be spawned in places which the Survivors have recently searched, depending on the whims of the Director. Some people may notice that there are not a lot of First Aid Kits in Mercy Hospital. On Expert, health kits are commonly replaced by Pain Pills. Only on Advanced and lower will the Director spawn health kits at a fairly frequent rate.

In The Passing, First Aid Kits can sometimes be recovered from dead Fallen Survivors if they are carrying it.

Usage
It takes five seconds to use the First Aid Kit to heal yourself or another Survivor, during which you cannot defend yourself in any way. However, in Left 4 Dead 2, if you are under the effects of Adrenaline while healing yourself or another Survivor, it will only take three seconds. Instead of restoring a set amount of health, First Aid Kits will only restore 80% of damage the Survivor has taken. For example, if a Survivor has taken 70% damage, using a First Aid Kit will add 56% (80% of 70) to the Survivor's health, bringing the Survivor to 86% health. This healing is not based on any temporary health a Survivor might have after taking pain pills, and will remove any extra health gained by them. After incapacitation, Survivors will always have only 1 permanent health (the rest will be temporary), and thus will always receive 80 health points from a First Aid Kit. Note that First Aid Kits can never bring a Survivor back to 100% health, so using more to try to do so is a waste.

Defibrillator
"What the fu- aww hell I'm back here again!"

- Coach "Come on! Work, damn it!"

- Nick

The Defibrillator (also referred by Survivors as "chest paddles") is a medical resource featured only in Left 4 Dead 2. It is a one-time use only device that will revive a dead Survivor.

For game balancing purposes, Survivors cannot carry a Defibrillator and First Aid Kit at the same time.

Official Description
Bring teammates back from the dead. Like the First Aid Kit, a Defibrillator Unit is a one-time use item. Defibs can resuscitate fallen teammates, and take three seconds to use.

Usage
To use the Defibrillator, a player must first select it from inventory. This action will reveal where the closest teammate's corpse is lying via emitting a faint red glow. The user must approach the corpse and hold either of the attack buttons. A charging meter, which takes three seconds to complete, will appear followed by a short burst of electricity whereupon the dead Survivor's body will do a sudden jump and will be resurrected.

A resurrected Survivor comes back with 50 health (which is permanent health that does not decline like the temporary health obtained after being incapacitated). This player will have no items save for their secondary weapon, and must pick up their dropped equipment from the ground. A team message will come up on the left side of the screen identifying who brought whom back to life.

Tactically, it is recommended most Survivors carry First Aid Kits and to designate just one Survivor as the team's "Defibrillator medic". The Defibrillator is especially useful when playing on Expert and Realism Modes since the risks of a player dying prematurely are extreme in the former and in Realism Mode (along with Versus Mode), there are no rescue closets.

Defibrillators don't tend to spawn often, usually one per level apart from a few exceptions. If a Survivor is on the verge of death, the Director will tend to spawn one nearby. If the group is near a first aid cabinet, one Defibrillator may be included in the cabinet.

A Defibrillator can be used on any Survivor corpse - even if they have already been saved from a rescue closet. It should be noted that in earlier versions of the game if the defibrillator was used on a player's own corpse, the player's "consciousness" would enter the body of the newly-revived teammate. Moreover defibrillation was impossible if somebody was standing over the target corpse. These variables have been changed subsequently. Now when a Survivor is revived, the Survivor in a rescue closet will disappear and if a Survivor is rescued via rescue closet, the corpse does. This serves to maintain the number of Survivor graphic images at a maximum of four at anytime.

Depending on the situation, there may be times when it is a good strategy to intentionally kill a teammate, then revive them with the defibrillator. For example, killing a near-death teammate who is operating at the margin of health in black and white visual mode then using the defibrillator on them will reset their incapacitation count, and restore them to 50 permanent health. This tactic can be crucial on the higher difficulty settings where health packs and pills/adrenaline are at a premium. However, it's better to ask for permission from teammate before doing this, sometimes it will be mistaken as trolling or teamkilling.

Survivor Bots cannot pick up or use Defibrillators. The only way they can hold it is if a human player was controlling a Survivor in an online game, and picks one up, but then quits or goes idle, leaving the bot to take over the Survivor holding the Defibrillator. They will not use it and will immediately swap it for a first aid kit if one is available lying around.

If someone dies from hanging (holding onto a ledge), they cannot be revived using the Defibrillator since they fall and become a ragdoll. However if they are killed by another Survivor whilst hanging (rather than losing their grip and falling to their death) their body may fall into an accessible area that allows them to be defibrillated and revived. An example of one such opportunity exists in respect to the stairs to the first floor in the finale of Dead Center.

If timed correctly, it is possible to defibrillate a hanging player after killing them with friendly fire, such that their corpse falls to the ground below and the player returns to life there rather than with the survivor that revived them. For example, speedrunners playing the Dead Center campaign would use this glitch in The Hotel on a player hanging on the ledge outside the room with the map. This ledge is directly over the lobby of the hotel, as well as the safe room, and using this glitch allowed the players to skip the entire level.

In reality, portable defibrillators cannot revive somebody from death; they are merely designed to physically restart the fibrillating (i.e. contracting out of sync) heart muscle, which may revive a person from the near-death condition (unless the patient's brain is dead, which takes about 5 minutes after the heart stopped beating properly). It specifically cannot save people from dying of wounds, so the in-game defibrillator is just a symbolic 'revival item', not any sort of realistic representation of a defibrillator.

On very rare occasions when a Survivor died, it required 2 or more defibrillators to revive the Survivor. This was patched on February 20, 2011.

Defibrillator behavior in Versus was changed slightly as of the June 18th 2010 update: The Director now spawns Defibrillators based on map length, and are limited to only one spawn per map unless there are multiple guaranteed spawn points on a map, e.g. The Atrium. Reviving a dead Survivor also results in a penalty of 25 points.

Pain Pills
"Pills here!"

- The Survivors "Ah, a little pick me up."

- Francis/Nick

Pain Pills, unlike the First Aid Kit, will only give the user 50 temporary points of health when taken. When carried by Survivors, it is held on the Survivor's right hip, probably on the belt.

Pain Pills can be given to teammates by pressing the melee button (right mouse button on PC by default, or left trigger on Xbox 360).

Since the health from Pain Pills is only temporary, it will slowly decrease over time, dropping one point every few seconds until all of the temporary health is gone. The Pain Pills you take will restore your movement speed and stop you from limping for as long as your total health is above or equal to 40%. Since temporary health goes down one point every five seconds, the effects of Pain Pills will last four minutes and 10 seconds, assuming no damage is taken.

Keep in mind that when taking damage while both permanent health and temporary health exist, permanent health will be taken first. If you have temporary health and your actual health is reduced to 1, your temporary health will continue dropping either from damage or time until it runs out, leaving you with 1% health until you either heal or get incapacitated.

Adrenaline Shot
"Grabbin' a shot!"

- The Survivors

Adrenaline Shots are included in Left 4 Dead 2, occupying the temporary healing slot.

Official Description
An Adrenaline Shot gives you a fifteen-second health and energy boost that lets you run faster, use items & revive twice as fast, and run through zombies without getting slowed down by their attacks.

Usage
Upon injection, the user gains 25 temporary health. For 15 seconds, they move faster, do not experience melee fatigue, are immune to the Horde's slowing attacks and their speed isn't affected by water.

It also increases the speed of using First Aid Kits, reviving Survivors, completing objectives (e.g. pouring gas cans into the generator in Scavenge), reloading and switching weapons or items.

As temporary side effects, the user also experiences tunnel vision and monophonic sound, hindering their ability to determine the direction from where a sound came. This can become annoying during a split screen campaign if one player uses Adrenaline too much, as the monophonic penalty affects both players.

This item could become valuable at the end of a finale, where Survivors must reach a rescue vehicle while being impeded by the Horde.

Like Pain pills, the Adrenaline Shot can be passed to a teammate by using the melee button.

The Adrenaline Shot is a very precious item during a Scavenge game, as it can increase your speed and the speed of the gas pouring by roughly 50%. Generally two shots will be spawned during a Scavenge game.

The Adrenaline Shot in-game is based on real-life emergency "EpiPen" auto-injectors, which are filled with synthesized epinephrine: literal adrenaline. The adrenaline acts as a vasoconstrictor, slowing the body's allergic response and delaying the victim from going into anaphylactic shock. Since as much as 15% of the United States population is considered 'at-risk' for anaphylaxis, it is not beyond the realm of plausibility for the adrenaline shots to be found as often as they are, particularly if they were included as part of CEDA's Emergency Relief Supplies.

Behind the Scenes
Early screenshots show that at one time the first Aid Kit had a more box-like shape, didn't look like it was made out of soft materials, and had a carrying handle. This design can still be seen in the final version's First Aid icon.

Early videos showed it was possible to share med kits like pills instead of healing them (as seen as in this video at 0:36).

The placeholder for the adrenaline shot was nothing like a syringe, rather a re-skinned pain pills model with a yellow bottle. The texture can still be found in Left 4 Dead 2 files. It then became a syringe similar to the one used in the HUD before the current look for adrenaline.

Likewise, the defibrillator's world model placeholder was a re-skinned first Aid Kit model. Its textures can still be found in Left 4 Dead 2 files.