Zombie Apocalypse Addon - Everything Can Be Customized

Turn your Minecraft world into a long-term zombie survival scenario where daytime is no longer safe.

Zombie Apocalypse Addon replaces the usual "survive the night, relax during the day" loop with constant pressure, escalating danger, event surges, and deep server-side control. Zombie-class mobs can spawn around players during both day and night, hordes and blood moons can raise the pressure even higher, and enemy stats can scale as the world gets older.

This is not just "more zombies." It is a configurable zombie survival framework built for servers, challenge worlds, apocalypse packs, and long-running PvE worlds.

Quick Info

Multiplayer: install on the server only
Client install: optional for multiplayer
Singleplayer: install on the client, because singleplayer runs an integrated server
Current targets: NeoForge 1.21.1 and Forge 1.20.1
All admin commands require OP level 2
Most major systems can be changed live with commands

What This Mod Adds

Custom zombie-class spawning around players during both day and night
Optional zombie sunlight immunity
Optional baby zombie spawn control
Natural and manual horde events
Random and forced blood moon nights
Morning day-counter announcements
Manual apocalypse day control
Early-world daylight spawn grace period
Day-based difficulty progression
Advanced attribute tuning for spawned zombie-class mobs
Biome and dimension-based spawn and stat behavior
Temporary spawn pressure relief after player death
Persistent kill tracking and milestone advancements
Optional bonus zombie drops, including configurable gunpowder drops
Optional spawn particles and sounds
Detailed config comments for easier setup

Zombie-class mobs include:

Zombie
Husk
Drowned
Zombie Villager

Core Gameplay Systems

Constant Threat Spawning

Custom spawn waves can run near survival players all day and night.

You can control:

how often spawn checks happen
the chance of a spawn wave
how many mobs are attempted per wave
the per-player nearby zombie cap
spawn range around each player
minimum spawn distance
spawn-position attempts per mob
whether overworld spawns require open sky
whether baby zombie spawns are allowed

This lets you tune the mod for anything from a tense vanilla-style survival world to a full hardcore apocalypse server.

Horde Events

Hordes are timed high-pressure zombie surges with their own settings.

You can configure:

day interval for horde scheduling
chance a scheduled horde actually starts
horde duration
event spawn interval
horde wave size
horde spawn multiplier
on-screen event notifications

Admins can also start or stop hordes manually.

Blood Moon Nights

Blood moons can happen randomly at night or be forced manually.

During a blood moon:

spawn pressure increases heavily
event multipliers stack with normal spawning systems
players can receive on-screen alerts when notifications are enabled

Day Counter and Day Control

The mod includes an apocalypse day counter system.

Show the current day on screen every morning
Toggle morning day announcements in config or by command
Check the current day with /zday status
Set the apocalypse day manually with /zday set <day>

When the day is changed, apocalypse event scheduling state is reset so horde and blood moon logic stays consistent.

Early-Day Daylight Spawn Grace

If you want the beginning of a world to be less punishing during daylight, daytime custom spawning can be delayed until a chosen day.

Examples:

0 = daytime spawning is active immediately
10 = daytime spawning only starts on day 10
15 = daytime spawning only starts on day 15

This can be changed in the config or live with command.

Difficulty Scaling

Zombie pressure can scale as the world progresses.

The mod supports:

scaling start day
maximum scaling day
legacy speed and health scaling
full attribute scaling through the advanced attribute system

This creates a stronger long-term survival curve instead of flat difficulty.

Variant, Biome, and Dimension Logic

Spawn composition and stat behavior can change based on where mobs spawn.

Supported behavior includes:

more husks in desert-like biomes
more drowned in water-heavy biomes
mushroom fields as optional safe zones
optional custom spawning in the Nether and End
biome and dimension context multipliers for attributes

Death Cooldown

After a player dies, spawn pressure can be reduced temporarily to avoid repeated instant deaths.

This is useful on servers and harder setups where nonstop pressure can otherwise snowball too hard.

Stats, Milestones, Drops, and Effects

The mod includes support systems around the main apocalypse gameplay:

persistent zombie kill tracking
death cooldown tracking
optional bonus zombie drops
configurable gunpowder drops from zombie-class mobs
optional spawn particles and sounds
optional debug logging
zombie kill milestone advancements at 250, 1000, and 3000 kills

Advanced Attribute System

One of the largest systems in the mod is the attribute pipeline for zombie-class mobs when they enter the world.

Supported attributes:

Health
Attack Damage
Movement Speed
Armor
Follow Range
Knockback Resistance

Attribute Flow

For each affected mob, values are applied in this order:

Start from vanilla base values
Apply global base profile
Apply per-variant profile if enabled
Apply biome and dimension context multipliers if enabled
Apply attribute-based day scaling if enabled
Apply legacy health and speed scaling compatibility values
Clamp to safe limits

Why This Matters

This lets you build very specific difficulty behavior.

Examples:

all spawned mobs are slightly faster globally
husks hit harder than standard zombies
drowned are tankier in water biomes
Nether spawns are faster and more aggressive
late-game mobs detect players from farther away

You can keep the system simple, or tune it deeply for server balance.

Commands

All commands require OP level 2.

General

/zhelp - Show built-in help
/zburn <true|false> - Control whether zombies burn in daylight
/zkill - Remove zombie-class entities from loaded levels

Day Control

/zday - Show current world day status
/zday status - Show current world day and time-of-day
/zday set <day> - Set the apocalypse day counter

Events

/zhorde start - Start a horde immediately
/zhorde stop - Stop the active horde
/zhorde status - Show horde, blood moon, and multiplier state
/zbloodmoon - Force a blood moon now or queue it for tonight

Stats

/zstats - Show your own stats or server summary from console
/zstats <player> - Show stats for a specific player
/zstats all - Show server totals
/zstats clear - Clear tracked stats, cooldowns, and milestone progress

Spawn Settings

/zdayspawn status - Show current spawn settings
/zdayspawn enabled <true|false> - Toggle custom spawning
/zdayspawn chance <0.0-1.0> - Set spawn-wave chance
/zdayspawn babychance <0.0-1.0> - Set baby zombie chance, use 0.0 to disable new baby zombie-class spawns
/zdayspawn interval <ticks> - Set normal spawn interval
/zdayspawn eventinterval <ticks> - Set horde/blood moon spawn interval
/zdayspawn amount <1-50> - Set mobs attempted per wave
/zdayspawn attempts <1-40> - Set spawn-position attempts per mob
/zdayspawn max <1-500> - Set nearby zombie cap per player
/zdayspawn range <16-128> - Set spawn range around players
/zdayspawn mindist <8-64> - Set minimum spawn distance from players
/zdayspawn daylightstart <day> - Delay daytime custom spawning until a chosen day
/zdayspawn sky <true|false> - Require open sky for overworld custom spawns
/zdayspawn variants <true|false> - Toggle zombie variant spawning
/zdayspawn nightboost <true|false> - Toggle night spawn boost
/zdayspawn horde <true|false> - Toggle horde system
/zdayspawn hordechance <0.0-1.0> - Set scheduled horde chance
/zdayspawn daycounter <true|false> - Toggle morning day-counter titles
/zdayspawn bloodmoon <true|false> - Toggle random blood moons
/zdayspawn scaling <true|false> - Toggle day-based scaling
/zdayspawn attributes <true|false> - Toggle advanced attributes
/zdayspawn attributescaling <true|false> - Toggle attribute day scaling
/zdayspawn variantprofiles <true|false> - Toggle per-variant attribute profiles
/zdayspawn contextprofiles <true|false> - Toggle biome/dimension context profiles
/zdayspawn biomes <true|false> - Toggle biome spawn modifiers
/zdayspawn nether <true|false> - Allow custom spawning in the Nether
/zdayspawn end <true|false> - Allow custom spawning in the End
/zdayspawn cooldown <true|false> - Toggle death cooldown system
/zdayspawn effects <true|false> - Toggle spawn particles and sounds
/zdayspawn debug <true|false> - Toggle debug logging

Scaling

/zscaling status - Show current scaling state

Live Attribute Tuning

/zattr status - Show attribute system status
/zattr keys - Show key format help
/zattr keys all - Show all supported numeric and toggle keys
/zattr get <key> - Read a numeric attribute value
/zattr set <key> <value> - Set a numeric attribute value
/zattr toggle <key> <true|false> - Change a supported boolean attribute toggle

/zattr Key Groups

Numeric key groups:

base.<health|attack|speed|armor|follow|knockback>.<multiplier|bonus>
scale.<health|attack|speed|armor|follow|knockback>.<multiplier|bonus>
variant.<zombie|husk|drowned|villager>.<health|attack|speed|armor|follow|knockback>.<multiplier|bonus>
context.<desert|water|mushroom|nether|end>.<health|attack|speed|armor|follow|knockback>.multiplier
legacy.<speedMultiplier|healthBonus>

Toggle keys:

attributes.enabled
attributes.scaling
attributes.variantProfiles
attributes.contextProfiles

If you are unsure what key to use, run:

/zattr keys all

Config and Tuning

The config file is designed to be readable and includes comments, safe ranges, and explanations for new users.

You can use it for:

a more hostile vanilla-style survival world
a PvE server with escalating danger
a challenge pack apocalypse setup
a long-running world with increasing pressure over time
a softer early game that becomes harder later
a brutal server where day and night are both dangerous

Most major settings can also be changed live with commands, which makes balancing much easier during active testing.

Suggested Starting Points

For a lighter survival world:

delay daylight spawning with daylightstart
keep horde chance low
keep scaling slow
keep baby zombie chance low or disabled

For a hardcore apocalypse world:

enable day and night custom spawning
enable hordes and blood moons
enable scaling and advanced attributes
increase event wave size and event multipliers

Installation Notes

Multiplayer servers only need the mod installed on the server.
Players can join without installing the mod on their client.
For singleplayer, install it on the client.
Use the NeoForge file for Minecraft 1.21.1.
Use the Forge file for Minecraft 1.20.1.
Back up your world before changing major spawn or scaling settings.

If you want a configurable zombie apocalypse system with constant pressure, escalating events, live admin controls, and deep stat tuning, this mod is built for exactly that.