Zombie Infection

This article is about the official game mode. For community versions with a similar name and concept, see Zombie game mode.

Murky's swamp town.

“

Huddle up, humans- but not too close, you never know who will turn... — Zombie Infection publicity blurb

”

Zombie Infection is a community-created game mode added in Scream Fortress XV with the October 9, 2023 Patch. It features the RED team (also referred to as "Humans" or "Survivors") fighting to survive against the undead hordes of BLU team Zombies.

Gameplay

At the start of a round, all players begin on RED team and are given a small period of time to prepare their defenses. After this, a certain number of players based on the amount of players on RED team are randomly chosen to become infected. When a RED player dies, they are moved to the BLU team and play as a Zombie. BLU team wins if they manage to infect all Humans, while RED team wins if the remaining Humans hold out long enough without all being infected. Eight seconds are added to the timer for each RED player that is infected.

Humans

• When there are 3 Humans left, all surviving Humans deal Mini-Crit damage. When there is 1 Human left, the last surviving Human deals full Critical hits.

Weapon modifications

•   The Homewrecker can destroy a Zombie Engineer's EMP grenade.
•   The Pomson 6000 now causes a Zombie's ability to go on cooldown on hit.
•   The Huntsman and Fortified Compound deal double damage.
•   The B.A.S.E. Jumper cannot be deployed if the user is among the last three survivors.
•   Heavy's Miniguns deal 40% less damage.
•   Sentry Guns deal 60% less damage.

Zombies

• Zombies are mostly limited to only using melee attacks (doing 65 base damage), however, each Zombie class features a unique ability or passive.
• Zombies cannot deal Critical hits, pick up Ammo or Health packs, and do not drop ammo on death (except for the Engineer if he has an unused EMP grenade).
• Zombies never take fall damage.
• All Zombies wear a Voodoo-Cursed Soul, have a green footstep Halloween Spell effect, and have a voice modifier applied that deepens their voice.
• Zombies explode on death (dealing no damage) and drop a small health kit (Zombie Pyros drop a medium health kit instead).

The number of starting Zombies is predefined for each team with less than 18 players. For teams with 18 or more players, it is calculated by rounding up the result of the number of RED players divided by 5.

RED players	Nº of Zombies
1 – 4	1
5 – 8	2
9 – 12	3
13 – 17	4
18	4
19	4
20	4
21	5
22	5
23	5
24	5

Zombie abilities

Class	Abilities	Cooldown	HUD icon
Zombie Scout	Speed Demon   Passive: 75% faster movement speed (520 Hu/s) and 25% extra jump height.   Passive: Triple jump.   Passive: 50 less max health (75 total max health).	N/A
Zombie Soldier	Pounce   Ability: Leap into the air, in the direction the player is looking. Landing on a player's head results in a stomp similar to the Mantreads.   This leap counts as blast jumping.   Passive: 25 extra max health (225 total max health).	5 seconds
Zombie Pyro	Dragon's Breath   Ability: Shoot a Dragon's Fury fireball. The initial cast of the fireball can reflect projectiles and airblast enemies.   Passive: Immunity to all flames and liquids. Explodes upon death and knocks back enemies in a 125 Hammer unit radius.   Passive: Every hit ignites Humans for a total of 3 seconds, dealing 8 damage per second. Burning enemies take Mini-Crits.   Passive: On death, no health kit is dropped.   Passive: 75 extra max health (250 total max health).   Passive: 30% damage penalty.	5 seconds
Zombie Demoman	Blast Charge   Ability: Explosive Charge, similar to the Charge when wearing a shield, dealing 275 damage in a 150 Hammer unit radius.   The player is ÜberCharged and made immobile for a short time before the charge.   Passive: 25 extra max health (200 total max health).	6 seconds
Zombie Heavy	The Tank   Passive: Deals 220% damage, immune to knockback, 35% damage resistance, 50% resistance to Sentry Gun damage, and increased knockback dealt.   Passive: Instantly destroy buildings in a single hit.   Passive: 225 extra max health (525 total max health).   Passive: 10% slower move speed (207 Hu/s).   Passive: Drop a medium health kit upon death.	N/A
Zombie Engineer	EMP Grenade   Ability: Throw an EMP bomb, temporarily disabling any buildings for 6.5 seconds and doing 110 damage after 3.5 seconds in a 500 Hammer units radius.   EMP explosion shakes the screen of players near it.   Passive: 25 extra max health (150 total max health).   Passive: If an Engineer dies with an unused EMP grenade, he drops a medium ammo pack.	9 seconds
Zombie Medic	Heal   Ability: Heals and ÜberCharges himself and teammates in a 275 Hammer units radius around him. Cannot attack while using this ability.   The healing and ÜberCharge effect is identical to the Overheal magic spell.   Forces the player into a third person perspective when used.   Passive: Heal nearby teammates passively.   Passive: 25 extra max health (175 total max health).	7 seconds
Zombie Sniper	Spit   Ability: Spit an acid ball that, when it lands, damages any Human and building that stands on it. The acid deals fire damage, which melts the Spy-cicle, and deals half damage to buildings.   The initial acid ball hit deals 45 damage and the acid pool deals 25 damage per tick (50 damage per second) and stays for 5 seconds. Standing on the acid as a Human shows a green burning overlay on the HUD.   The acid pool has a 130 Hammer unit radius.   The acid ball can be held for a maximum of 5 seconds.   Passive: Drop a pool of acid on death.   Passive: 25 extra max health (150 total max health).	10 seconds
Zombie Spy	Reveal   Ability: Mark Humans in a radius around the player, revealing their location with an outline.   Reveal has a radius 1000 Hammer units and reveals Humans for 20 seconds.   Passive: Automatically cloak. Attacking or using Reveal uncloaks the Zombie Spy for 3 seconds.   Passive: 25 extra max health (150 total max health).	10 seconds

Strategy

Main article: Community Zombie Infection strategy

Maps

Main article: List of maps

Zombie Infection maps carry the zi_ prefix; community maps are identified with an italic font.

Name	Picture	File name
Atoll		zi_atoll
Blazehattan		zi_blazehattan
Devastation		zi_devastation_final1
Murky		zi_murky
Sanitarium		zi_sanitarium
Woods		zi_woods

Changelog

This is the changelog of the gamemode before it was added to the game.

Changelog:

V3 Patch Notes (27.9.2023)

• Visual Adjustments:
  • New User Interface
    • Added an entirely new graphical user interface to Zombie infection.
    • New UI includes ability icons for each class as well as an on-screen ability charge meter.
  • Added screenshake effect to Zombie spy's reveal ability.

• Adjustments:
  • The last three survivors now receive Mini-Crits, in addition to the final survivor receiving Critical Hits.
  • Zombies now receive an additional 8 seconds per kill, previously 5.
  • Added chat notifications when survivors receive a bonus.
  • Changed Zombie weapons to use item definition for their respective voodoo soul item.
    • With this change, Zombies no longer see "The Prinny Machete" on their HUD.
  • Changed Zombie weapons to use correct fist sound effects and kill icon.
  • Removed !hud chat command.
  • Removed !version chat command.
  • Removed debug logging code from Workshop release.
  • Adjusted convars to disable autobalance voting and team scramble voting.
  • Changed the way viewmodel animations are set in code to reduce jerkiness, especially at high ping.

• Bug Fixes:
  • Fixed numerous bugs related to humans respawning after a round in which they were a Zombie.
  • Fixed bugs related to the Zombies not seeing their own particles and player model.
  • Fixed bugs related to Zombie particle effects not properly dispersing when a Zombie has died.
  • Fixed bugs related to announcer voice lines playing inappropriately.
  • Fixed a bug where Zombie Spy's reveal range was multiplied by 10.
  • Fixed a bug where Zombie Pyro was able to be made wet.
  • Fixed a bug that caused a charging Zombie Demoman to not explode in some situations.
  • Fixed a bug related to Engineer's Gunslinger not being correctly re-applied after a round has ended.
  • EMP grenade no longer causes Engineer to T-pose.
  • Spit no longer causes Sniper to T-pose.
  • Fixed multiple crash bugs.
  • Many more undocumented bug fixes.

• Balance Changes:
  • Zombie Changes:
    • Reduced melee range and bounds multiplier to 1.
    • Zombies max ammo for primary, secondary, and metal is now 0.
    • Zombies no longer have a speed boost at all times but have a small speed boost when not engaged in combat for 5 seconds.
    • Zombies now drop a small health kit on death.
    • Zombies no longer drop a small ammo box on death.
    • Reduced damage multiplier for all Zombie classes to 1, except for Zombie Pyro which is reduced to 0.7.
    • Zombies now take 40% less damage from heavy's minigun and sentry guns.
  • Survivor Weapon Adjustments
    • The Crusader's Crossbow now deals 300% damage to Zombies.
    • The Huntsman now deals 200% damage to Zombies.
    • Zombies now deal 50% less damage to Demoman with a shield equipped.
    • the Rocket Jumper and the Stickybomb Jumper start with a full clip, but can now only hold 1 reserve ammo at any time.
  • Voice Responses
    • Placeholder Yeti voice responses have been removed and replaced with the original class voice lines at 0.7 pitch.

• Class Specific Changes:
  • Zombie Soldier
    • Pounce now launches you in the direction you are facing.
    • Pouncing now correctly removes FL_ONGROUND and adds TF_COND_BLASTJUMPING.
    • Zombie soldier can now stomp enemies when falling from a pounce with enough velocity.
  • Zombie Medic
    • Healing ability now gives players in an area around you a brief ÜberCharge and quick healing.
    • Range of healing ability reduced from 350 to 275.
  • Zombie Engineer
    • Building disable time for EMP grenade raised from 5 to 6.5.
    • Changed grenade scale to 1.4 from 1.2.
    • Changed grenade hitbox scale from 0.25 to 1.
    • Multiple EMP grenades hitting a single building no longer stacks disable time.
    • If the Zombie engineer dies while their EMP grenade is charged, they will drop a small ammo box.
  • Zombie Scout
    • Zombie scout now has triple jump.
  • Zombie Heavy
    • Health reduced to 600 from 740.
  • Zombie Spy
    • Zombie spy no longer leaves green footstep trails.

Update history

October 9, 2023 Patch #1 (Scream Fortress 2023)

• Added maps: Atoll, Devastation, Murky, Sanitarium, and Woods.

October 13, 2023 Patch

• Updated zi_murky, zi_atoll, zi_devastation_final1, zi_woods, and zi_sanitarium
  • These changes are aimed to make playing as a Zombie more engaging, and to weaken the Human meta of bunkering without hurting their ability to roam and fight
    • Zombie Spy is now passively cloaked, only losing his cloak for 3 seconds when attacking or using his "Reveal" ability
      • This change will allow Zombie Spy to circumvent Sentry Guns that are watching large areas, and allow him to sneak into or around strongholds
    • Zombie Soldier's "Pounce" ability is now significantly higher, and has a 5 second cooldown (from 8)
      • These changes will bolster Zombie Soldier's role as a Recon pick and a roof buster, capable of launching through sentry fire
    • Zombie Sniper's "Spit" ability now damages buildables
    • Zombie Sniper now drops a puddle of spit on death
      • Both of these changes will make you feel like you're contributing more with your spit, and if that's not enough, you at least get to drop one on death to cause a small area of denial
    • Zombie Pyro no longer drops small health kits
    • Zombie Pyro's "Hellspawn" passive now releases a flaming explosion on death on top of the existing Gas Passer cloud
      • These changes should strengthen their afterburn capability, and make them a scarier threat if you let them too close
    • Zombie Heavy's "Tank" ability now adds the Battalion's Backup buff (immunity to Critical hits, 35% resistance to regular damage, and a 50% resistance to Sentry Gun damage)
    • Zombie Heavy deals 20% increased melee damage
      • Sentry and Crit resistance will bring Zombie Heavy's effective hp up much higher, buffing his role as a tank that you really oughta stay away from. His slower speed is unchanged, so you're still able to run. The changes will just make bunkering much more difficult with him around.
    • Zombie Engineer's EMP no longer rolls on shallow surfaces, and now does 110 damage instead of fractional damage
      • This change will turn EMP grenades into a much more immediate threat, instantly breaking mini Sentry Guns, crippling level 1 Sentry Guns, and wounding other buildings
    • Zombie Scout's "Speed Demon" passive now comes and additional 25% jump height boost
      • Zombie Scout already has a triple jump, but increasing jump height will make him even more of a pest buzzing around your head, and better at climbing onto roofs once a hold is destroyed
    • 1/5 of the server will be converted to zombies at the end of setup (from 1/6), and will also round up
      • It's become clear that there simply aren't enough zombies selected at the start of the round. Initial pushes should be easier to perform with a couple more units.
    • Sentry Guns deal 40% damage to zombies (from 60%)
      • Engineers are simply way too oppressive. The Dispenser is invaluable for the sake of ammo, and the sentry still has use as a knockback tool, but now should be significantly less frustrating to play against.
    • Demoman shield items no longer halve the damage taken by zombies
      • He was just too strong and incredibly unfun to duel. The extended reach of swords is already amazing against melee-only characters. His strong maneuverability is unchanged.
    • Zombie Medic Heal cooldown reduced to 7 seconds (previously 11)
    • All Zombies except for Scout, heavy, and Spy, now have +25 HP (from +10)
  • Fixed a bug where Zombie Demo could detonate himself before the charge had started
  • Fixed a bug where Bonk! Atomic Punch could persist through Zombie conversion
  • Fixed various issues caused by Zombie Demo surviving his own charge
  • Fixed issues with the Zombie HUD not correctly displaying certain strings
  • Fixed exploit related to adding additional time
  • Added additional HIDEHUD bits to remove irrelevant HUD elements when playing Zombie
  • Added an instructional video (Thanks Funicular!)

October 19, 2023 Patch

• Updated zi_murky, zi_atoll, zi_devastation_final1, zi_woods, and zi_sanitarium
  • If a game is in progress and there are no players on BLU team or RED team the game will now end
  • Fixed a bug that allowed Dead Ringer Spies to die without triggering a round loss
  • Fixed a bug that caused Zombies to not see combat text correctly
  • Fixed a bug that caused Rocket Launchers and Sticky Bomb Launchers to start with a low ammo
  • Fixed a bug that caused changing player loadout to kill human players (particularly on Murky)
  • Fixed an issue with missing particle effects for Medic's Heal ability
  • Adjusted the number of Zombies selected at round start for low player counts
  • Corrected unintended changes in the last update
    • Changed the damage dealt by Zombie Soldier's Stomp
      • In the previous update, Soldier would instantly kill his stomp target. This was not intended
      • The new damage calculation is (10 + fall damage x 3). This is the same as the Mantreads
    • Changed the Sentry Gun to deal 40% damage to Zombies
      • In the previous update, this was 35%. This was not intended
    • Added a sound effect to Pyro's explosion of flames on death
    • Removed some debug print statements
  • Reworked Demoman's Blast Charge to fix several exploits and bugs
    • These changes should also make Blast Charge more reliable and less frustrating to use
  • Blast Charge is now triggered based on the player's velocity
    • When player's speed drops below a threshold while charging, they explode
    • Additionally, anything that would usually interrupt a shield charge will now trigger the explosion
  • Fixed a bug that caused ÜberCharge applied by Blast Charge to persist longer than intended
  • Fixed a bug that caused Blast Charge to fail to kill the player in situations where the player should be killed
  • Fixed a bug that caused Blast Charge to briefly display the player's first person view before detonation
  • Fixed a bug that caused the player to be unable to attack, jump or duck after surviving Blast Charge
  • Fixed many bugs that caused Blast Charge to fail to detonate
  • Fixed many bugs related to Blast Charge being cast at the same time as being converted to Zombie

July 18, 2024 Patch #1 (Summer 2024 Update)

• Updated zi_intro.webm media file.

October 10, 2024 Patch #1 (Scream Fortress 2024)

• Added map: Blazehattan
• Updated zi_murky, zi_devastation_final1, zi_atoll, zi_woods, and zi_sanitarium
  • General Changes
    • Zombies no longer spawn instantly- their respawn timer is now dependant on the map
    • Changed team names to "Survivors" and "Zombies" (Instead of "RED" and "BLU")
      • Note: this change is only visible in casual mode or servers with mp_tournament set to 1
    • Survivor Spy can now disguise as a Zombie and will be seen as a Zombie by the enemy team (Thanks Sprinkles!)
      • Note: disguised Survivor Spies will still be highlighted by Zombie Spy’s “Reveal” ability
    • The Pomson 6000 now puts Zombie abilities on cooldown on hit
    • Survivor Pyro can now destroy Zombie Engineer's EMP Grenade by hitting it with the Homewrecker
    • Walking in to Zombie Sniper's Spit now consumes the Spycicle^(sic) and prevents initial damage
    • Standing in Zombie Sniper's Spit now emits additional sound effects and a burning green HUD overlay
    • Added new kill icons for every zombie attack
  • Zombie Changes
    • Removed the out-of-combat speed buff from all Zombies
    • Zombie Pyro
      • Zombie Pyro has a new ability - "Dragon's Breath"
        • Fires a Dragon's Fury fireball
        • The initial cast of the fireball can reflect projectiles and airblast enemies
      • Zombie Pyro now deals Mini-Crits to burning players on melee hit
      • Zombie Pyro now creates a small explosion on death, knocking back enemies in a 125 hu radius
      • Zombie Pyro no longer emits a Gas Passer cloud on death
    • Zombie Demoman
      • Added new sound effects to telegraph Zombie Demoman's Blast Charge ability
    • Zombie Heavy
      • Zombie Heavy's health reduced to 450 (from 600)
      • Zombie Heavy now drops a Medium Health Kit on death
    • Zombie Sniper
      • Zombie Sniper's Spit damage vs buildables is now reduced by half
      • Zombie Sniper's Spit now applies a screen overlay to players standing in the pool
    • Zombie Medic
      • Zombie Medic now emits health like a Dispenser to nearby Zombies
      • Zombie Medic can no longer attack while using Heal
      • Added a new sound effect for Zombie Medic's Heal ability
    • Zombie Spy
      • Zombie Spy no longer emits particle effects while cloaked, making him fully invisible when not attacking. Jumpscare warning!
    • Zombie Scout
      • With other zombies getting slower, Zombie Scout's speed stands out more than ever before
  • Bug Fixes
    • Fixed a bug that allowed Zombie Demoman to survive his own Blast Charge (Thanks gasous nebule!)
    • Fixed a bug that caused Zombie Demoman to not receive kill credit when killing players with Blast Charge
    • Fixed a bug that caused Zombies to not gib correctly
    • Fixed a bug that caused Zombie cosmetics to persist on RED players after the round restarts
    • Fixed a bug that caused Zombie Sniper's Spit Pool to nudge players slightly in certain circumstances
    • Fixed a bug that caused players to have the incorrect player skin when respawning at round start
    • Fixed a bug that would cause players to become stuck in spectate mode when attempting to join a game in progress
    • Fixed an issue with "game_text" entities not being correctly cleared after round reset

October 11, 2024 Patch

• Updated zi_atoll, zi_blazehattan, zi_devastation_final1, zi_murky, zi_sanitarium, and zi_woods
  • Fixed missing overlay material for Sniper's Spit ability
  • Fixed missing particle effects for Pyro's Dragon's Breath ability
  • Fixed a bug that would cause players to get stuck in spectate mode^(sic) when attempting to join a game in progress

October 18, 2024 Patch

• Updated zi_atoll, zi_blazehattan, zi_devastation_final1, zi_murky, zi_sanitarium, and zi_woods
  • Reduced Zombie Engineer's EMP Grenade Cooldown from 10 seconds to 9 seconds
  • Adjusted Zombie Pyro's death explosion to briefly ignite players hit by the blast
  • Fixed a bug that allowed Zombie Medic to spawn infinite Dispenser entities (Thanks Psychicpie!)
  • Fixed Zombie Heavy's ability appearing as an active instead of a passive on the HUD (Thanks NeoDement!)
  • Fixed a bug that caused Zombie Heavy's knockback effect to trigger on afterburn damage when quickly swapping from Pyro to Heavy

October 25, 2024 Patch

• Updated zi_atoll, zi_blazehattan, zi_devastation_final1, zi_murky, zi_sanitarium, and zi_woods
  • General
    • Re-encoded all Zombie Infection sound effects as .WAV
      • This fixes issues with sound effects not playing correctly and spewing errors in the console
  • Bug fixes
    • Fixed a bug that caused Sniper's Spit Pool to deal much more damage than intended
    • Fixed a bug that caused team names to not display correctly when playing on mp_tournament mode
    • Fixed a bug where Engineer would sometimes scream like a charging Demoman while throwing an EMP Grenade
  • Zombie Changes
    • Sniper's Spit Pool damage vs Survivors no longer stacks when standing in multiple zones
    • Zombie Heavy is no longer immune to Critical hits
    • Zombie Heavy's max health raised to 525 (from 450)
    • Zombie Pyro's max health raised to 250 (from 175)
    • Zombie Pyro now drops a medium health kit on death
  • Survivor Changes
    • Crossbow weapons no longer have a flat damage multiplier against Zombies
    • The B.A.S.E Jumper^(sic) can no longer be deployed if you are one of the last three survivors
    • Jumper Weapons can no longer store reserve ammunition

November 4, 2024 Patch

• Updated zi_atoll, zi_blazehattan, zi_devastation_final1, zi_murky, zi_sanitarium, and zi_woods
  • Fixed an exploit allowing some players to respawn as a human or play as a human on the Zombie team.

Bugs

• Afterburn caused by the Pyro Zombie's on-hit ignite does not trigger hitsounds.
• The game mode's HUD elements can sometimes fail to load, and a large black or white line appears diagonally across the screen instead.
• The first person viewmodel arms can sometimes fail to load.
• Sometimes, players may join the game as a spectator.
  • The Voodoo-Cursed Soul and green footstep Halloween Spell effect ends up wherever a spectator is currently looking, which by default is in the center of the map.
    • These effects may also merge with the player upon changing rounds, even as a Human form. This can also obstruct first person viewmodels if they are attached to the player. The Voodoo-Cursed Soul merged with a player does not match the class they are currently playing as, instead it is the Voodoo-Cursed Soul of the class they were in the previous round.
• The Thriller taunt has a chance to replace the Zombie Heavy's High Noon kill taunt, when it does not normally replace kill taunts.
• The Zombie Heavy swings slower than the other Zombies.

Unused content

• Zombies under the effect of Jarate were originally meant to take Critical hits instead of Mini-Crits, as suggested by some commented out code.

Trivia

• This game mode was inspired by the Infection gametype in Halo: Reach.
• The Demoman Zombie, Sniper Zombie, and Heavy Zombie are inspired by Special Infected from Left 4 Dead 2.

Gallery

• 

  First person view for the Scout Zombie.

• 

  First person view for the Soldier Zombie.

• 

  First person view for the Pyro Zombie.

• 

  First person view for the Demoman Zombie.

• 

  First person view for the Heavy Zombie.

• 

  First person view for the Engineer Zombie.

• 

  First person view for the Medic Zombie.

• 

  First person view for the Sniper Zombie.

• 

  First person view for the Spy Zombie.

• 

  The EMP grenade used by the Engineer Zombie.

• 

  Bug showing a large diagonal white line across the screen, instead of the game mode's HUD elements, as well as the first person viewmodel hands failing to load.

• 

  Bug showing the mode's HUD elements failing to load.

• 

  The HUD when playing as a Zombie.

References

 When updates release, the code will likely have shifted a few lines or have moved somewhere else entirely.