Setup Siege Server

Siege and Base Defense

For servers built around defending a base. Every 10th night a horde arrives at dusk, and during those nights zombies break weak walls, build steps and fill gaps, and stack on each other to climb defenses. Each siege makes the next one harder, and from day 50 zombies attack bases every night and day.

This is the Siege Nights recipe from the Config Guide, plus towering and a night ceiling. Back up the world first, and read Before You Start if this is your first guide.

Commands

Run these in order:

/za preset standard
/za events on
/za events interval 10
/za events chance 1
/za events dusk on
/za events duration 10
/za scaling steps 10
/za scaling extrazombies 4
/za breaking on
/za breaking startday 50
/za breaking events on
/za placing on
/za placing startday 50
/za placing events on
/za towering on
/za towering startday 50
/za towering events on
/za spawn nightmax 60

• The events lines make every 10th day a guaranteed horde from dusk to about dawn.
• scaling steps 10 raises zombie strength once every 10 days, on the morning after each horde (days 11, 21, 31, ...). extrazombies 4 adds up to 4 zombies to every wave as strength rises.
• breaking, placing, and towering with startday 50 and events on work only during hordes and blood moons until day 50, then all the time.
• spawn nightmax 60 lets siege nights gather a bigger crowd than the normal cap of 50 around each player.

Config File

Edit with the server stopped. These go on top of the Standard values:

# [horde]
enableHordeEvents = true
hordeIntervalDays = 10
hordeStartChance = 1.0
hordeStartsAtDusk = true
hordeDurationMinutes = 10
# [scaling]
scalingStepDays = 10
maxExtraZombiesPerWave = 4
# [blockbreaking]
enableZombieBlockBreaking = true
zombieBlockBreakingStartDay = 50
zombieBlockBreakingDuringEvents = true
# [blockplacing]
enableZombieBlockPlacing = true
zombieBlockPlacingStartDay = 50
zombieBlockPlacingDuringEvents = true
# [towering]
enableZombieTowering = true
zombieToweringStartDay = 50
zombieToweringDuringEvents = true
# [nightspawning]
maxNightZombiesPerPlayer = 60

What To Expect

• Normal days and nights before day 50: Standard waves. Zombies do not touch blocks.
• Siege nights (days 10, 20, 30, 40): a horde title at dusk. Waves every second at three times the chance, with 5 zombies each plus the scaling bonus. Zombies with a target that is behind a wall try to break it, about once every 5 seconds each with a 20% chance per try. They break blocks up to wooden-door hardness: dirt, glass, wood, and doors. Stone, ores, chests, machines, and light sources are protected.
• Building: zombies place cobblestone to make one-block steps or fill one-block gaps, up to 8 blocks per zombie. They cannot build floating bridges.
• Towers: when at least three zombies crowd below a raised player or a wall they cannot path around, they stack up to one block above the target's level. At most 3 towers chase each player. Towers come apart again on their own when the target is reachable on the ground.
• Blood moons count as siege nights too. Run /za bloodmoon off if only the scheduled hordes should allow sieges.
• From day 50: breaking, placing, and towering run every day and night.
• Rules that still apply: zombies only break or build while chasing a target and when they are blocked, never while wandering. The mobGriefing game rule and claim or protection mods can stop them.

Base-Building Tips For Players

• Stone-type blocks (stone, cobblestone, bricks, deepslate) need a pickaxe, so zombies cannot break them unless an admin allows it.
• Lights keep new waves from spawning inside the base, and zombies cannot break the lights by default.
• A one-block gap or one-block step will not stop zombies that can place blocks. Height and solid stone walls will.
• Towers need a crowd. Narrow approaches and spread-out defenses keep crowds small.

Tuning

To make it...	Run
Let late-game zombies break stone too	/za breaking toolblocks on and /za breaking hardness 50
Break only soft blocks	/za breaking hardness 1.0
Make breaking faster	/za breaking chance 0.4
Build with a different block	/za placing block minecraft:dirt
Allow more blocks per zombie	/za placing limit 16
Taller towers	/za towering offset 3
Fewer towers per player	/za towering maxperplayer 1
Top zombies leap off towers	/za towering jumping on
Tower zombies stand instead of sit	/za towering pose stand
Sieges every 5 days	/za events interval 5 and /za scaling steps 5
Keep sieges to event nights forever	/za breaking startday 1000000 (same for placing and towering)
Only the scheduled hordes	/za bloodmoon off
Bigger siege crowds	/za spawn nightmax 100

With mobGriefing Off

Some servers turn the mobGriefing game rule off to stop creeper damage. That also stops zombie breaking and placing. To keep zombie sieges while creepers stay harmless:

/za breaking mobgriefing off
/za placing mobgriefing off

Claim and protection mods can still cancel zombie block changes, because the mod always fires the normal block events.

Claims

Zombie breaking and placing go through the loader's normal block events, so claim mods that block mob griefing inside claims protect those areas. Test one claimed base on a siege night before announcing sieges to players.

Undo

/za breaking off
/za placing off
/za towering off
/za scaling steps 0
/za scaling extrazombies 0
/za preset standard

/za towering off also takes apart every loaded tower safely. Blocks zombies placed stay in the world.