LethalBreed siege manual
Annexes
Français
Edition
1.21.11, Fabric
Subject
Holding a shelter against a horde that learns
Licence
MIT

A siege manual, for anyone sleeping outdoors

LethalBreed

They read the distance between you and them, and they close it. Over the top, under the floor, straight through. A wall buys you seconds, and this manual tells you how many.

At dusk, a horde massed at the foot of an obsidian wall, with a staircase of blocks the zombies have placed climbing the face towards a villager stranded on top.
Plate I They do not climb. They put blocks under their own feet and step up onto them, one at a time, while the rest work on the stone in the same spot.

What a wall buys you

Nothing in this mod goes through stone. Everything eats it. The only question worth asking a material is how many seconds it holds, and the answer is one division.

A zombie standing against a block adds 0.04 points of progress per tick, divided by the hardness of the block. At 1.0 the block falls. That is the formula the server runs, copied here without rounding.

Breach calculator

The mod's shipped defaults

1

1 block

The block falls in1.938 ticks
Crowd multiplier1.0one breaker
Wall pierced right through1.9seconds
Thickness to hold one minute32blocks deep

How many bodies fit in front of the breach

The wall does not lose to one zombie. It loses to the sixth.

Every extra breaker on the same block adds 0.6 to the multiplier, and the sum is bounded at 4.0. The bound lands on the sixth body: past that, the queue behind buys them nothing, and that is your one piece of good news for the night.

What sets the number is not the size of the horde, it is the geometry in front of the block. A corridor one block wide presents a single face. Open ground presents eight.

An aerial view of a long obsidian wall lit by a row of lanterns: one single point of the face is under attack, all the rest is untouched.
Plate II Above, forty blocks of wall and a single point of attack: rallying gathers them instead of spreading them out. Below, drag the width of the passage. The bodies touching the block count, the rest wait.

3 blocks

Time to open a two-block breach, bare-handed, by material
MaterialHardnessAloneCurrent passageSaturated, six bodies

They go over, and the sky closes nothing

A tall wall does not push the horde back, it asks it to build a staircase. It knows how.

The distance field does not read a face as a refusal, it reads it as a cost. When the cost of going round beats the cost of building, the zombie puts a block under its feet, steps up, and does it again. A tower two blocks wide changes nothing in that sum: it lengthens it.

What changes it is an overhang. A ledge sticking out one block forces the column to step sideways, and a column that steps sideways falls into nothing.

Four zombies stacked at the top of a column of blocks they have just placed against an obsidian wall, one of them still holding its shovel.
Plate III Above, the column as it appears in game. Below, the section: the same column against a bare wall, then against a wall with a ledge.

They dig, and water does not stop them

Moats are the trap that looks like a plan. They do not swim, that much is true. They fill.

Water is not a wall to the distance field, it is a buildable cell. A flooded trench does not send the horde away, it points at a place to put blocks, and it turns your ditch into a bridge while you are looking somewhere else.

What actually works fits in one sentence: a moat stops nothing if it has a floor. What stops them is the void under the bridge, because a block placed over nothing falls with whoever placed it.

Plate IV Section of the trench. The red line is the cheapest route as the field scores it.

3 blocks

2 blocks

Counting the nights

Difficulty does not follow your progress, it follows the clock. Thirty minutes of world, one phase more, whether you built or slept.

Each step pulls up health, damage, speed, the number of zombies out at night and how often their waves come. Every one of those curves has its own ceiling, and a hard cap above it: a zombie will never one-shot a player in full armour.

Phase ladder

Curves from ProgressionConfig

6

World time0minutes elapsed
Health multiplier1.00ceiling 8.0
Damage multiplier1.00ceiling 6.0
Zombies out1.0times the normal cap

Telling the unusual apart

Eight variants, each unlocked by a phase. None of them is a final tier: the last arrives at the eleventh and the others keep coming all the same.

The share climbs with the counter, from one zombie in twenty at the start to one in three at the ceiling. What really changes from the sixth phase on is not their number, it is that two different ones turn up in the same wave.

    Putting the manual in the world

    Two files in a folder, and the first night already looks nothing like the one before it.

    1. Install Fabric for Minecraft 1.21.11, then Fabric API.
    2. Drop the LethalBreed jar into mods/.
    3. Run it once, close it, then open config/lethalbreed.json if you want to change anything. It is all in there, and the in-game settings screen writes to the same file.

    The distance field is solved on the graphics card when there is one, and falls back to the processor without changing anything in the game when there is not. A dedicated server with a card in it uses that too.