Perk-a-Colas are a feature that can be found in all Zombies maps, except for Dead Ops Arcade and the Call of Duty: World at War version of Nacht der Untoten. Each drink gives the player a perk to help them survive and fend off the zombie horde. Some are based off of perks found in multiplayer (such as Juggernog and Speed Cola mirroring Juggernaut and Sleight of Hand respectively). The same machines spawn on fixed locations on each map, with the exception of Shi No Numa, Shangri-La, Moon, Nuketown Zombies and Die Rise, where the Perk-a-Cola machines will randomly spawn at a spawn point, with some exceptions. If a player is knocked down, he/she will lose all the perks he/she has purchased and will have to buy them again, unless he/she has obtained the Focusing Stone, completed the Richtofen's Grand Scheme, completed Maxis' or Richtofen's side of Mined Games , or successfully uses Tombstone Soda or Who's Who.
Juggernog
Juggernog
- "When you need some help to get by, something to make you feel strong. Reach for Juggernog tonight, sugar seduction delight! When you need to feel big and strong, reach for Juggernog tonight!"
- — Juggernog Jingle
Juggernog Jingle 
- Main article: Juggernog
Juggernog enhances the player's health by 250%. Therefore, in order for a player to be downed, it will take 4 hits (six quick hits with permanent Juggernog on Buried, Die Rise and Tranzit) instead of only two from normal zombies and Space Monkeys, or five instead of three from Hellhounds, Crawler Zombies and Minions. George A. Romero will down the player in two hits without Juggernog, three hits with it. The perk costs 2500 points, and is by many considered the most important perk to have. It is located in:
- The German side of the starting room in Verrückt
- One of huts in Shi No Numa (spawns in random order along with other Perk-a-Colas)
- Near the Bouncing Betty in Der Riese
- In a small corner next to the Bowie Knife in Kino der Toten
- In the war room next to the panic room in "Five"
- In the PM63 room in Ascension
- At the base of the top half of the ship in Call of the Dead
- Opposite of the PM63 next to the Mud-Pit Maze, or near the entrance to the cave system in the Mine Cart area in Shangri-La (changes place with Speed Cola)
- Next to the teleporter in the No Man's Land in Moon (changes place with Speed Cola each time the area is visited)
- Spawns as one of the meteors in random order and location every 100 kills in Nuketown Zombies
- In the small upstairs building in Town (in both Survival and TranZit)
- Top floor in the small house in Farm
- In one of the elevators in the skyscraper with access to the roof in Die Rise (changes place with Double Tap Root Beer, Pack-a-Punch Machine and Mule Kick)
- Near the Gondola at docks in Mob Of The Dead (needed to be powered up in Afterlife Mode)
- Behind the debris near where the mystery box first spawns in Buried (the debris needs to be destroyed by The Giant to reach it)
- Same place in Borough as Buried
According to the machine, it is made with real eggs. Every character enjoys its taste (with the exception of Nikolai Belinski in Der Riese with a remark about it being the worst vodka he's tasted). All of the characters in Mob of the Dead appear to dislike its taste. It mirrors Juggernaut.
Speed Cola
Speed Cola
- "Your hands are slow, your movements sluggish, your lack of speed, just brings you anguish. Just take a sip, you will move faster. Just try it now! And speed is mastered! Press those lips against the only one that really moves you. Speed Cola speeds up your life!"
- — Speed Cola jingle
Speed Cola Jingle
- Main article: Speed Cola
Speed Cola decreases reload time by 50% and allows barriers to be built 60% faster. It costs 3000 points. It is located in:
- Next to the kitchen in the American side in Verrückt
- One of huts in Shi No Numa (spawns in random order along with other Perk-a-Colas)
- Near the FG42 in Der Riese
- In the room with the Stakeout and MP40 in Kino der Toten
- In the hallway leading to the elevator to other floors in the starting floor in "Five"
- In a small room leading to Lunar Lander Б (nearest to the Pack-a-Punch Machine) in Ascension
- At the bottom of the Ice Slide in Call of the Dead
- Opposite of the MPL next to the Mud-Pit Maze, or near the entrance to the cave system in the Mine Cart area in Shangri-La (changes place with Juggernog)
- Next to the teleporter in the No Man's Land in Moon (changes place with Juggernog each time the area is visited)
- Spawns as one of the meteors in random order and location every 100 kills in Nuketown Zombies
- Inside the Diner in TranZit
- In the bank in Town
- Bottom floor in the small house in Farm
- In one of the elevators in the starting skyscraper in Die Rise (changes place with Who's Who)
- In the corner of the Warden's Office near the table in Mob of the Dead and Cell Block
- On the second floor of the Courthouse in Buried
According to Richtofen, the main ingredient may rot the consumer's mind, and according to Nikolai Belinski, it is spicy. Every character enjoys its taste. It mirrors Sleight of Hand.
Quick Revive
Quick Revive
- "When everything's, been draggin' you down, grabbed you by the hair and pulled you to the ground, if you wanna get up, you need a little revive. If you wanna get up... YOU NEED A LITTLE REVIVE!"
- — Quick Revive Jingle
Quick Revive Jingle Alternate (older) version of the jingle - Main article: Quick Revive
Quick Revive decreases the player's revive time with 50% in co-op, and allows the player to revive themselves in solo (in Call of Duty: Black Ops and Call of Duty: Black Ops II) by giving the player Mustang and Sally while automatically becoming revived within ten seconds when downed. It also does not require power. To balance this, it is only available three times. It costs 1500 points in co-op in all games and in solo in Call of Duty: World at War, and 500 in solo Call of Duty: Black Ops and Call of Duty: Black Ops II. This "Second Chance" version of Quick Revive is not featured in Mob of the Dead due to the addition of Afterlife Mode. It is located in:
- The American side of the starting room in Verrückt
- One of huts in Shi No Numa (spawns in random order along with other Perk-a-Colas)
- Near the Teleporter C in Der Riese
- In the starting room in Kino der Toten, "Five", Ascension, Call of the Dead, Shangri-La, Farm and TranZit
- In the Receiving Area in Moon
- Spawns as a meteor at the start of the game somewhere in the starting area in Nuketown Zombies (Solo only)
- Top floor in the bar in Town
- In front of the barn in Farm
- In an elevator near M14 or the PDW-57 in Die Rise
- Can be seen after falling down from the starting room in Buried
According to characters, it tastes like fish. Every character, aside from Takeo Masaki, greatly dislikes its taste. It partially mirrors Second Chance.
Double Tap Root Beer
Double Tap Root Beer
- "Cowboys can't shoot slow or they'll end up below. When they need some help, they reach for the Root beer shelf (Ye-haa) Cowboys can't shoot slow, or they'll end up below, when they need some help, they reach for the Root beer shelf. YA THIRSTY PARTNER!?"
- — Double Tap Root Beer Jingle
Double Tap Root Beer Jingle
- Main article: Double Tap Root Beer
Double Tap Root Beer (Double Tap II in Call of Duty: Black Ops II) increases the player's fire rate by 25%, and in Call of Duty: Black Ops II also makes bullet weapons shoot two bullets (twice the pellets on shotguns) in addition, effectively doubling damage. This can either be a blessing or a curse; while the player can potentially kill zombies faster, the ammo consumption can grow too big on weapons with an already high rate of fire and substantially decrease accuracy. Despite this, it is very useful on weapons with low rates of fire, such as pump-action shotguns, bolt-action rifles, BAR, HK21 et cetera where the ammo will not drain uncontrollably but further increasing the weapons' lethality. This perk costs 2000 points. It is located in:
- The German side next to the MP40 in Verrückt
- One of huts in Shi No Numa (spawns in random order along with other Perk-a-Colas)
- On the lower side of the bridge in Der Riese
- In the alley in Kino der Toten
- Next to the elevator leading to the starting room in the war room in "Five"
- Not available in Ascension
- In the far back end of the ship near the Claymore in Call of the Dead
- In any of the rooms below ground in Shangri-La (changes place with Stamin-Up, PhD Flopper and Deadshot Daiquiri)
- In the lower room in the laboratories in Moon
- Spawns as one of the meteors in random order and location every 100 kills in Nuketown Zombies
- Top floor of the barn in Farm (in both Survival and TranZit)
- Next to the Mystery Box spawn in the alley in Town
- In one of the elevators in the skyscraper with access to the roof in Die Rise (changes place with Juggernog, Pack-a-Punch Machine and Mule Kick)
- In the Citadel Tunnels in Mob Of The Dead
- On the top floor near the Gondola, also where Electric Cherry is when playing Mob of the Dead, in Cell Block
- Inside the Mansion on Buried on the right of the entrance.
- On Grief Mode Buried to the left of outside the Mansion.
According to Tank Dempsey, it tastes chewy. Every character either comment on its effect or its jingle. It mirrors the perk from multiplayer, Double Tap.
Stamin-Up
Stamin-Up
"Stamin-up-Min-Up! (x3) When you need some extra runnin', when you need some extra time, when you want to keep on gunnin', when you like a twist of lime. When you need to keep on moving, when you need a get-away, when you need to keep on groovin', when you need that vitamin K, babe, you know you want me! Let's run the extra mile! I'll open your eyes and I'll make you see! I'll make it worth your while! Stamin-up-Min-Up! Sounds like it's Staaaaamin-Up time! Oh yeah, drink it baby. Bring it!"
Stamin-Up Jingle
- Main article: Stamin-Up
Stamin-Up increases the player's movement usefulness, as it increases movement speed by 7% and sprint duration by 100%. Stamin-Up was first introduced in Ascension. It can greatly assist the player in large maps such as Call of the Dead to get to other places faster, as well as with heavy weaponry (such as light machine guns and launchers) to allow the player more mobility. It costs 2000 points. It is located in:
- Near the AK-74u in Ascension
- Behind the lighthouse in a small building near the Stakeout in Call of the Dead
- In any of the rooms below ground in Shangri-La (changes place with Double Tap Root Beer, PhD Flopper and Deadshot Daiquiri)
- In Tunnel 11 near Semtex in Moon
- Ground floor of the bar in Town (in TranZit)
- Outside the bar in a small corner near M14 in Town (in Survival)
- End of the hedge maze in Buried, near Pack-A-Punch.
According to the characters, it has a sour taste. It mirrors Marathon, Lightweight, and Extreme Conditioning.
PhD Flopper
PhD Flopper
- "PhD, the night-time scene. PhD, the streets are mean. PhD, the things I have seen, the good (PhD), the bad, and the in-between (Flopper). When you dive to prone, you are surely gonna own, PhD (Flopper)! When you dive to prone, it's gonna shake ya to the bone, all the zombies gonna groan, 'cause of PhD! PhD, the feelin's growing strong. PhD, so right that it feels wrong. PhD, like the chorus of a song (Flopper). PhD, not short but not too long. Slap your body to the floor, everybody needs some more, of your lovin', your explosive lovin'. When you dive to prone, it's gonna shake ya to the bone, all the zombies gonna groan, cause of PhD! (Flopper)! Damn straight!"
- — The jingle of the PhD Flopper.
PhD Flopper Jingle
- Main article: PhD Flopper
PhD Flopper gives the player immunity against explosive and falling damage, as well as triggering a strong explosion when diving to prone on a fall that would normally give fall damage. PhD Flopper was first introduced in Ascension. This perk is very useful if the player uses explosive weapons a lot, particularly Ray Gun, Scavenger and Mustang and Sally. Its explosive dive ability can also be used as a stand-alone up to approximately round 20. It costs 2000 points. It is located in:
- Near Lunar Lander Д (nearest to MP5K) in Ascension
- Under the lighthouse side entrance (near MP5K) in Call of the Dead
- In any of the rooms below ground in Shangri-La (changes place with Double Tap Root Beer, Stamin-Up and Deadshot Daiquiri)
- In the bio dome in Moon
- The Library area (Mob of the Dead spawn area) in Cell Block
- It is unavailable but can be seen in both Die Rise and Mob of the Dead
According to the characters, it is incredibly chewy (even suggesting it can be eaten instead of drunk), and according to Robert Englund, it is made of chemicals. It mirrors Lightweight Pro and partially Flak Jacket. The characters, such as Samantha , comment on it tasting of prunes.
Deadshot Daiquiri
- "To err is human, to forgive is divine. Well I'm not forgiving, and the error ain't mine! They ain't quite human; least they're not to my eyes. One sip of this and I'll give 'em the shock of their lives! Yeah, we got the guns and we got the bombs! In deadshot heaven, we pop skulls for fun! Zero in baby, zero on that spot, the hot spot baby, give it all you got! So quit complainin', about your bad aimin'! Just try, try again for me! With the headshot power of Deadshot Daiquiri!"
- — The jingle of Deadshot Daiquiri.
Deadshot Daiquiri
Deadshot Daiquiri Jingle
Deadshot Daiquiri increases hip fire accuracy by 35%, reduces recoil on all weapons (most notably on sniper rifles), removes idle sway on sniper rifles and changes the auto-aim to target head instead of torso (except on sniper rifles). Deadshot Daiquiri was first introduced in Call of the Dead. It costs 1500 points on consoles, and 1000 on PC (as PC does not support auto-aim, giving less benefit of the perk). It is located in:
- On the lighthouse catwalk next to the zipline in Call of the Dead
- In any of the rooms below ground in Shangri-La (changes place with Double Tap Root Beer, Stamin-Up and PhD Flopper)
- Top floor in the laboratories in Moon
- Roof access room in the Infirmary next to the room with the Uzi and Hellhound wall in Mob of the Dead
- In the Cafeteria in Cell Block
According to the characters, it has a very sweet taste, even resembling yogurt and strawberries to Takeo Masaki and Samantha Maxis (respectively). It mirrors Steady Aim and partially Grip.
Mule Kick
Mule Kick
- "Legend tells us of a man, a hero in a tortured land, where Señoritas lived in fear. Their lonely nights in deep despair, he was EL BURRO! (Hee-Haw, Hee-Haw). Across the fields, across the plains. He ran so fast he dodged the rain. He was El Burro! He hurried in to save the day, gun in hand, in thrice they say. He was strong like a Mule, he was stubborn like a Mule, he even kicked like a Mule, El Burro! (El Burro!). A man not equal, so they say. But some and more, it's just the way! He was El Burro! He was EL BURRO! EL BURRO!"
- — The jingle of Mule Kick, cut from Moon due to the fact that the machine is in an airless environment. The jingle can be heard in-game at Die Rise
Mule Kick Jingle
- Main article: Mule Kick
Mule Kick gives the player the ability to carry a third weapon but upon going down you will lose the third weapon. Mule Kick was first introduced in Moon, but on 9/27/12, it was made available on all maps in Call of Duty: Black Ops (except Dead Ops Arcade) via a hotfix. It costs 4000 points and is located in:
- In the starting room, next to the M1A1 Carbine in Nacht der Untoten
- In the first cell block near Thompson in Verrückt
- In the starting room, near Gewehr 43 in Shi No Numa
- In the melting room near Thompson in Der Riese
- Near PM63 in Kino der Toten
- In the war room near Juggernog in "Five"
- Below Speed Cola in Ascension
- On the top far end of the ship in Call of the Dead
- In the waterfall in Shangri-La
- Near the AK-74u in Moon
- In one of the elevators in the skyscraper with access to the roof in Die Rise (changes place with Juggernog, Pack-a-Punch Machine and Double Tap Root Beer)
- Unavaliable but visible with PhD Flopper on the dock in Mob Of The Dead
- In the area near the M14 in Cell Block (Grief only)
- On the top of the gunsmith shop in Buried
According to Tank Dempsey, it tastes like beer, while according to Takeo Masaki it tastes like cola, suggesting it has a deprived taste. It partially mirrors Overkill.
Tombstone Soda
Tombstone Soda
- "Rest in pieces, down for the count. No revival, you're bleedin' out. Your epitaph says you died a wealthy man, but you can have it all come back and seal the master plan with Tombstone! It's Tombstone! It's Tombstone! It's Tombstone! Health is drainin' you're on the ropes. Death is waitin', don't lose your hopes. Your will and testament ain't making that much sense, you're listed as the only heir to whom you may bequest. It's Tombstone! It's Tombstone! It's Tombstone! It's Tombstone! Tombstone"
- — The Tombstone Soda jingle.
Tombstone Soda Jingle
- Main article: Tombstone Soda
Tombstone Soda allows the player to collect back their equipment after death via a power-up (as well as die prematurely in the process), including all of the perks (with the exception of the Tombstone Soda), weapons and ammo. As the player goes down, the player can hold the 'use' button to die prematurely. When the round ends, the player will respawn and be able to collect the power-up (shaped like a tombstone) left on the spot that the player was downed on. Only the particular player can collect the power-up, and the power-up will disappear in a period of time. Being revived will make the perk not take effect. Tombstone Soda only appears in Green Run and does not appear in solo. It costs 2000 points. It is located in:
- In the room available after turning on the power in the Power Plant (in TranZit)
- On the alley leading to Double Tap Root Beer 2.0 in Town (Survival only)
Its taste and characters' opinions of it are unknown. It does not mirror any multiplayer perk, although it has some similarities with Second Chance.
Who's Who
- "I was talkin' to myself just the other day, I was hearin' lots of things I never thought I'd say, but one thing I said really blew my mind (Who's who?) I said I don't know me, but I know you, and if you listen closely we can talk it through, it ain't as simple as we're gonna find (Who's who?) I think I will save you, I think I don't blame you, 'cause I like you and you like me. I was talkin' to myself just the other day, then the bad man came and took me away, I feel bad, but not as bad as me (Get off me, man!) I was talkin' to myself just the other day, (You've got the wrong man!) then the bad man came and took me away, (I'm not your man!) I feel bad, but not as bad as me (Not who I am!) (Who's Who?)"
- — Who's Who Jingle
Who's Who
Who's Who Jingle
- Main article: Who's Who
Who's Who allows the player to spawn a doppelganger of their character when downed, who can then revive the original player as well as others. The doppelganger spawns near the original character, has blurry vision and is equipped with only an M1911. If the player succeeds in reviving oneself, all weapons and perks are kept except Who's Who. In addition, dying in a way that the player cannot be revived (such as falling down the gap), Who's Who will respawn the player without having to wait for the round's end. It currently only appears in Die Rise. It costs 2000 points. It is located in:
- In one of the elevators in the starting skyscraper in Die Rise (changes place with Speed Cola)
Its taste and characters' opinions of it are unknown. It slighly shares similarities with the perk Second Chance.
Electric Cherry
Electric Cherry
Electric Cherry is a perk-a-cola introduced in the Zombie Map Mob of the Dead for Call of Duty: Black Ops II. It creates an electro-static shockwave around the player whenever they reload their weapon. The perk costs 2000 points to purchase, the color for this perk is light blue (although the color of the drink is cherry red), and the icon is a red cherry. It has no similarities with any multiplayer perks. There is also no known jingle for this perk-a-cola.
- Electric Cherry is located near the above entrance to the Gondola, and is also next to a crafting station.
This beverage is necessary to complete the A Burst of Flavor achievement/trophy, requiring killing ten zombies within the given radius of one entire shockwave.
Vulture Aid
Vulture Aid
- Main article: Vulture Aid
Vulture Aid is a perk-a-cola introduced in the Zombie Map Buried for Call of Duty: Black Ops II. It costs 3000 points and has four effects. This perk is also necessary to complete either the Richtofen or Maxis side of the easter egg.
- It can let you see the locations of perks, wall guns, the Pack a Punch machine and the mystery box wherever you are on the map.
- It makes zombies occasionally drop small amounts of ammo and points, they disappear after a while.
- Will cause certain zombies to release a green colored cloud of gas upon death, which will cause them to be ignored by the zombies while standing in it.
- The eyes of the zombies will glow much brighter making them easier to see.
Vulture-Aid is located in the back of the church near the alter in Buried. You need to give The Giant (Zombies) some booze so he can break the debris in front of the church entrance to get inside. It partially mirrors Scavenger, as well as Engineer.
Cut Perk-a-Colas
Amm-O-Matic
- Main article: Amm-O-Matic
The unused texture for the Amm-O-Matic
Amm-O-Matic (also known as Amm-o-Matic) is a canceled vending machine in Der Rise. Although it cannot be seen or used in Der Riese, there is a stairway that leads up to it. The stairway is visible, but the player is unable to climb to the top of it. It is located somewhere near Juggernog. It seems that the idea was scrapped at the last second by Treyarch. Unused sound files that remain on the games disc confirm that this machine was designed to give the player a Max Ammo upon purchase. It is likely that this machine would have been expensive or could only be used a specific number of times. It is not known if it will appear in future projects. Its color is sky blue, similar to the Quick Revive machine, and its symbol resembles a bullet.
Candolier
- Main article: Candolier
Candolier is a Perk-a-Cola machine that was originally set to appear in Call of Duty: Black Ops, but was cut from the game. Not much is known about the machine, but it is most likely going to be the same function as the perk Bandolier from Call of Duty 4 and World at War by giving the player the ability to carry extra ammo. Its color is light green, and its symbol is a showing of a row of bullets, implying the idea of carrying extra ammo upon the perk being bought and used.
Tufbrew
- Main article: Tufbrew
Tufbrew is a cut Perk-a-Cola referenced in Ascension's game files. The name suggests the perk may have increased the player's strength in other ways than Juggernog does.
Pronaide
- Main article: Pronaide
Pronaide was a cut perk in Ascension that would make the player go prone faster than normal. It can be assumed it was an early predecessor to PhD Flopper. Not much else is known about the perk.
Obtaining More than Four Perks
- Main article: Random Perk Bottle
Starting with the release of Ascension, the maps could contain more than four perks. However, the player can only buy four perks at one time: attempting to buy another when currently owning four will result in failure. To circumvent this, there are a few methods on maps after Ascension to obtain more than four, up to eight perks. The most popular is Random Perk Bottle, a power-up that awards every player with an extra random perk. Also, obtaining the Focusing Stone and completing Richtofen's Grand Scheme will award the player all perks that last until the end of the game. However, despite there being five with the release of Mule Kick in the Call of Duty: Black Ops versions of Verrückt, Shi No Numa, Der Riese, Kino der Toten and "Five", there is no way to obtain more than four. Tombstone Soda also allows the player to get more than four perks; the player must buy the wanted perks before collecting the tombstone, which gives the player the previously owned perks along with the newly bought ones. In Die Rise, killing all of the Minions without shooting them during their respective round will award players a free perk bottle. The player is also able to obtain the 6 perks on the map by completing the easter egg. In Buried, the player can obtain a free perk bottle by killing a certain number of the Mistresses. The player also acquires all 7 perks upon completion of the "Mined Games" easter egg on Buried for Maxis.
Trivia
- In Der Riese, going prone in front of the perk machines will give the player 25 points (although visually showing as 20 or 30 in Call of Duty: World at War). This is a joke as to how a quarter can sometimes be found in a vending machine.
- It is impossible to sprint, interact with other utilities and go prone while drinking a perk. The player is free however, to rebuild barriers.
- The Perk-a-Cola machines are powered by electricity, but require a relay of Element 115 inside to be powered for a purchased drink to take effect.
- When the player buys the Perk-a-Cola, the jingle is shortened and only its ending can be heard. They play the songs randomly if the player goes near the machines throughout the game.
- Speed Cola, Stamin-Up, Mule Kick,Tombstone Soda and Electric Cherry are the only machines where the player can actually see the drink in the machine.
- An unusable Juggernog bottle can be found on the table near the pool in the multiplayer map Villa in Call of Duty: Black Ops.
- An unusable Juggernog, Double Tap, Speed Cola and two Quick Revive bottles can be found in the glass case just in front of the Quick Revive vending machine in Kino der Toten.
- In Samantha's destroyed room, there are soda bottles for Juggernog, Quick Revive, Speed Cola and Double Tap Root Beer on the floor.
- When drinking the cola in Call of Duty: Black Ops, the third-person animation used seems to be a re-use of the animation for using the radio. The character will put the bottle up to his head and make talking motions.
- When drinking in the Wii version, the bottle does not come close to the character's lips.
- All Perk-a-Cola machines except for Mule Kick in Call of Duty: Black Ops have a bloody hand print on them.
- In Mob of the Dead, all the Perk-a-Colas and the Pack-a-Punch, with the exeption of Electric Cherry, have a strange static effect on them. But because of Mob of the Dead taking place before the Pack-a-Punch or the Perk Machines were even made, the Demonic Announcer was somehow able to bring them into the past, meaning that the Perk Machines and the Pack-a-Punch are active between two different points in time.
- In Mob of the Dead, the perk machines play a heavily distorted version of their jingles, resembling a bell toll.
- Among all the DLC Perks, they all cost 2000 points except Deadshot Daiquiri which is 1500 points(1000 on PC), Mule Kick which is 4000 points, and Vulture Aid Elixir which is 3000 points.
- As of the June 27, 2013 update, all Perk-A-Colas in Mob of the Dead have a updated HUD icon. It is most likely to fit in with the unique HUD on the map.
- In Buried an unknown perma-perk can be unlocked to allow the player(s) to retain their perks after being downed and revived.