Infestations & Sieges has hit the PTR today! A big thank you to all of our beta testers on Steam! Please note, whether you're new to the PTR or have been in the group a while, starting a new community is recommended for this update. Read on for the full patch notes. [Not in our Steam beta but want to be? Read all about it here.]

Happy holidays!

Table of Contents:

  • Overview
  • Update Details
    • Plague Hearts
    • Infesting Hordes
    • Infestations
    • Siege Sites
    • Siege Event
    • Radio Commands
    • Outpost Defenses
  • Known Issues


Every few years, the survivors of the zombie outbreak are reminded that the Blood Plague threatening their communities is constantly mutating and adapting new ways to kill them. Plague Hearts have recently started displaying a sinister level of intelligence and coordination, sending out new types of zombie hordes to locate and assault your Bases directly.

These new Infesting Hordes now create and reinforce Infestations, using them as forward operating bases along the path to your community. When Infestations finally arrive within striking distance of a Base, they form Siege Sites that regularly send Siege Hordes directly into your Base. These new directed Infestations and Sieges are a more deadly and dynamic threat than you’ve faced before, but can also be controlled with a bit of strategy and grit.

Now, your only hope for survival is to push back the Infestations and keep Sieges under control until you’re ready to take out the source of it all: the Plague Hearts.

Update Details

Plague Hearts

  • Now all Plague Hearts on a given map start out dormant - that is not actively trying to seek out and destroy your Base. However, they don’t remain dormant forever!
    • Dormant / awake Plague Hearts each have a unique icon on the map and menus
  • As you explore Plague Territory, certain actions now raise the alertness of a Plague Heart until it fully “awakens” and begins sending out Infesting Hordes.
  • After a Plague Heart is awakened, it will begin sending Infesting Hordes out to create and reinforce Infested Sites along the way to your Base
    • Awakened Plague Hearts never become dormant again and must be destroyed
  • Destroying a Plague Heart after it awakens will cause all of its created Infestations to wither over time, losing strength and zombies, until it dissipates on its own.

Infesting Hordes

  • Awakened Plague Hearts begin regularly launching Infesting Hordes out into the world
    • When arriving at an uninfested location, Infesting Hordes create new Infestations, effectively making an outpost for the Horde
    • When arriving at a currently infested location, Infesting Hordes increase the Severity of that Infestation, bolstering it with even MORE zombies
  • Infestations can also generate Infesting Hordes, though this does lower their Severity as a portion of the zombies pick up and follow a Screamer to a new location
  • Most outpostable sites, including player controlled Outposts, can become Infested by the arrival of an Infesting Horde, nullifying any active benefits until cleared out
  • Destroy an Infesting Horde before it arrives at a destination to slow Infestation growth
  • The more Noise in your base, the faster Infestations grow and spread to your base - quieter bases take longer for Hordes to locate and reach


  • Infestations, once created, have a number of pips above them to indicate their Severity Level
    • Higher Severity Infestations have more zombies, eventually attracting dangerous Freaks like Ferals and Juggernauts into the mix
  • Since Screamers control Infestations on behalf of the Plague Hearts, killing all Screamers present at an Infestation will clear the Infestation instantly
    • The Severity Level of an Infestation is tied to how many Screamers are present, so you always know how many to look for at each Severity
  • Each Infesting Horde that arrives at an Infestation will increase the Severity Level.
  • Each Infesting Horde that leaves from an Infestation will decrease the Severity Level
    • When a Plague Heart controlling an Infestation (indicated by highlighting the Infestation on the map) is destroyed, that Infestation’s Severity Level ticks down over time to 0 and eventually clears itself automatically
  • Infestations also increase the density of the ambient zombie population around them

Siege Sites

  • When an Infesting Horde reaches an infestable location close enough to launch a Horde directly at your Base, it may create a Siege Site instead of a regular Infestation
    • Siege Sites will have red pips instead of green, to indicate their severity
  • When an Infesting Horde reaches an existing Siege Site it increases the Severity Level
    • Similar to Infestations, Siege Site Severity indicates how the composition of zombies and freaks at the Site - higher Severities mean harder fights
  • As long as Siege Sites exist, there is a chance for them to trigger a Siege Event, which results in Siege Hordes being launched from every active Siege Site toward your Base
    • This decreases the Severity of a Siege Site, same as Infestations
    • Siege Hordes are released in waves until every Siege Site has reached 0 Severity and despawn (or Siege Sites are manually killed)
  • The chance of a Siege triggering is represented by your Base’s Threat
    • The number of Siege Sites and their Severity both increase Threat
    • Higher Threat means longer, harder Sieges that are triggered faster
  • Siege Sites can be attacked and pruned before a Siege triggers, just like Infestations
    • Killing all the Screamers present will also automatically clear Siege Sites

Siege Event

  • Sieges have a chance to trigger based on your current Threat level (higher Threat, the higher the chance and difficulty) 
    • The Siege itself takes some extra time before beginning, with the Siege Hordes collecting nearby outside of your base until they decide to strike
  • Unlike Infestations which get weaker as their Severity level decreases, the waves of Siege Hordes released by the Siege Sites launch in order from easiest to hardest
  • Siege Hordes assault the base whether you’re present or not, and once it has been triggered a Siege will only end when all Siege Sites are destroyed or depleted
  • If your Active Character is not present in your base at the end of a wave, you see a popup notification about how your Survivors did without you and a Siege Consequence
    • Siege Consequences are applied at random based on your selected Difficulty, but it’s never good: they range from survivor injuries to facility damage or worse
    • Arriving at your base anytime during a Siege will prevent any Siege Consequences from being applied for that wave and any you’re present for
      • If you miss a few waves you can still show up late and save the day - all Consequences stop when you arrive before that wave’s end
      • Additionally if you leave mid-siege to clear out Siege Sites and are successful before the end of a wave, you skip any Consequences

Radio Commands

  • You’re not in this alone - you can use the Radio to send Survivors from your Community to help deal with Infestations while you attend to other matters
  • The “Scout All Infestations” call will consume fuel in exchange for a Survivor driving around locating new Infestations you might not be aware of
  • The “Take out a nearby infestation” call will help mitigate some of the growth by automatically pruning an Infestation on the map for you

Outpost Defenses

  • Similar to Radio commands, your Outposts can also be leveraged to fight back against the Infestations by enabling Outpost Defenses
    • These Outpost Defenses have costs and durations, but when used correctly can provide unique strategies for containing Infestation growth
  • Landmines, when enabled on Outposts along frequently traveled Horde routes, will automatically blow them up, along with any ambient zombies as they enter the safezone, preventing Infestation growth
  • Zombie Bait, when enabled on Outposts in out of the way areas, will divert the path of Infesting Hordes and mess with their ability to reach your base effectively
  • Disruption Signal, when enabled on Cell Tower Outposts, will slow down the rate at which Infestations and Plague Hearts decide to act against you by confusing them
  • Hovering over your home base or outposts to see their scouting range. The player will be notified when Infesting hordes that path through these scouting ranges and their icons will be added to the map.

Known Issues

Below is a list of known issues within the Infestations and Sieges feature set that are currently active in the PTR build.

  • Armored Zombies are immune to the “Landmines” outpost defenses. 
  • Infesting hordes don't update their directional arrows on the map UI when rerouted by the “Lures” outpost defense.
  • Infested sites will not pulse their parent plague heart if they are outside of the plague sphere. 
  • Clients will see pips above siege sites as green instead of the intended red.
  • Clients don’t see outpost or home base scouting ranges when hovering over their icons in the map menu.
  • Dormant Plague Heart icons on the map menu don’t update for clients when the plague heart is awoken in a multiplayer session.
  • Safehouse outposts are currently missing the Zombie Lure outpost defense action.
  • Radio Tower outposts have the Signal Disruptor outpost defense action button in the incorrect location.