Configure Zombie Settings

Customize zombie population, speed, strength, behavior, senses, decomposition, and respawning on your Project Zomboid server.

Zombie behavior is controlled through the SandboxVars.lua file. Settings are divided into two groups: ZombieLore (individual zombie behavior) and ZombieConfig (population and respawning).

Editing Zombie Settings

On XGamingServer, go to Files and open:

Zomboid/Server/[servername]_SandboxVars.lua

Zombie lore settings use the ZombieLore prefix:

SandboxVars.lua

SandboxVars = {
    ZombieLore = {
        Speed = 2,
        Strength = 2,
        Toughness = 2,
        Transmission = 1,
        Mortality = 5,
        Reanimate = 3,
    },
}

Zombie Speed

Value	Setting	Description
1	Sprinters	Full-speed running zombies (hardest)
2	Fast Shamblers	Brisk walking pace (default Apocalypse)
3	Shamblers	Classic slow zombies
4	Random	Each zombie gets a random speed

Zombie Strength

Value	Setting	Description
1	Superhuman	Very high damage per hit
2	Normal	Default damage
3	Weak	Reduced damage
4	Random	Each zombie gets random strength

Zombie Toughness

Value	Setting	Description
1	Tough	Takes more hits to kill
2	Normal	Default health
3	Fragile	Dies easily
4	Random	Each zombie gets random toughness

Zombie Cognition

Value	Setting	Description
1	Navigate + Use Doors	Smartest — can open doors and path around obstacles
2	Navigate	Can path around obstacles but cannot open doors
3	Basic Navigation	Minimal intelligence (default)
4	Random	Each zombie gets random cognition

Day/Night Activity

Controls when zombies are most active. Combine with Speed settings for interesting gameplay.

Value	Setting	Description
1	Both	Active day and night equally (default)
2	Night	More active at night, sluggish during day
3	Day	More active during day, sluggish at night

💡 Tip: Set ActiveOnly = 2 with Speed = 1 to create night sprinters — zombies that sprint at night but are slow during the day. This is one of the most popular custom configurations.

Zombie Senses

Sight

Value	Setting
1	Eagle (very long range)
2	Normal (default)
3	Poor (short range)
4	Random

Hearing

Value	Setting
1	Pinpoint (extremely accurate)
2	Normal (default)
3	Poor
4	Random

Smell

Value	Setting
1	Bloodhound (strong detection)
2	Normal (default)
3	Poor

Memory

Value	Setting
1	Long (remembers your position a long time)
2	Normal (default)
3	Short
4	None (forgets immediately)
5	Random

Decomposition

Controls how zombies change over months of game time.

Value	Setting	Description
1	Slows and Weakens	Zombies get slower AND weaker over time
2	Slows	Zombies slow down but maintain strength
3	Weakens	Zombies weaken but maintain speed
4	No Effect	Zombies never decompose (default)

Zombie Behavior Flags

Setting	Type	Default	Description
`ThumpNoChasing`	boolean	false	Zombies attack structures even when not chasing a player
`ThumpOnConstruction`	boolean	true	Zombies destroy player-built constructions
`TriggerHouseAlarm`	boolean	false	Zombies can trigger house alarms
`ZombiesDragDown`	boolean	true	Zombies can drag players to the ground
`ZombiesFenceLunge`	boolean	true	Zombies can lunge over fences

Fake Dead (Playing Possum)

Value	Setting
1	Some zombies pretend to be dead — reanimate when you get close
2	Even killed zombies may get back up
3	Never pretend dead (all corpses are truly dead)

Crawl Under Vehicles

Value	Setting
1	Crawlers Only
2	Extremely Rare
3	Rare
4	Sometimes
5	Often (default)
6	Very Often
7	Always

Population Settings

These use the ZombieConfig prefix:

Setting	Default	Description
`PopulationMultiplier`	1.0	Overall zombie population (0.0 = none, 4.0 = insane)
`PopulationStartMultiplier`	1.0	Population multiplier on day 1
`PopulationPeakMultiplier`	1.0	Population multiplier at peak day
`PopulationPeakDay`	28	Day when population reaches its peak
`RespawnHours`	72.0	Hours before zombies respawn in cleared areas (0 = no respawn)
`RespawnUnseenHours`	16.0	Hours a cell must be unseen before respawn
`RespawnMultiplier`	0.1	Fraction of original zombies that respawn each cycle
`RedistributeHours`	12.0	How often zombies migrate across the map
`FollowSoundDistance`	100	Distance (tiles) zombies will investigate sounds
`RallyGroupSize`	20	Maximum zombie group/horde size
`RallyTravelDistance`	20	Distance groups will migrate
`RallyGroupSeparation`	15	Minimum distance between groups
`RallyGroupRadius`	3	Radius of a zombie group

Population Scale

`PopulationMultiplier`	Label
0.0	None
0.35	Low
1.0	Normal
2.0	High
3.0	Very High
4.0	Insane

Infection and Mortality

Infection settings are also under ZombieLore. See Infection and Mortality for the full guide covering transmission, mortality timelines, and reanimation.

Recommended Presets

Casual PvE

SandboxVars.lua

ZombieLore = {
    Speed = 3,
    Strength = 3,
    Toughness = 3,
    Transmission = 4,
    Cognition = 3,
    Memory = 3,
    Sight = 3,
    Hearing = 3,
    ActiveOnly = 1,
    Decomp = 1,
    DisableFakeDead = 3,
},
ZombieConfig = {
    PopulationMultiplier = 0.5,
    RespawnHours = 0.0,
},

Slow, weak zombies with no infection and no respawning.

Night Sprinters

SandboxVars.lua

ZombieLore = {
    Speed = 1,
    Strength = 2,
    Toughness = 2,
    ActiveOnly = 2,
    Sight = 1,
    Hearing = 1,
    Memory = 1,
    DisableFakeDead = 1,
},
ZombieConfig = {
    PopulationMultiplier = 1.5,
},

Sprinting zombies at night, sluggish during the day. Eagle eyesight and pinpoint hearing.

Hardcore Survival

SandboxVars.lua

ZombieLore = {
    Speed = 1,
    Strength = 1,
    Toughness = 1,
    Transmission = 1,
    Mortality = 5,
    Cognition = 1,
    Sight = 1,
    Hearing = 1,
    Memory = 1,
    ZombiesDragDown = true,
    ZombiesFenceLunge = true,
    Decomp = 4,
},
ZombieConfig = {
    PopulationMultiplier = 4.0,
    PopulationPeakDay = 14,
},

Maximum population sprinters that can open doors. No decomposition. Peak at day 14.

No Zombies (Building Server)

SandboxVars.lua

ZombieConfig = {
    PopulationMultiplier = 0.0,
    RespawnHours = 0.0,
},

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Configure Zombie Settings

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