LethalBreed siege manual Spawning Manual Français

Phased night spawning

Specimens of the plain zombie type appear naturally at night; their maximum count and their spawn cadence climb sharply with the difficulty phase. At tier 0, the mob-cap is zero and nothing spawns naturally, which is the "classic" baseline, not untouched vanilla behavior.

Mob-cap and frequency

The count of simultaneous zombies is floor(vanilla_cap × mobcap(phase)), the spawn cadence adds ceil(frequency(phase)) − 1 extra spawn passes per chunk per tick, that count being itself clamped to spawnMaxExtraPasses (512 by default, a safety net for the server-thread loop). Each pass still respects the cap, so it speeds up the filling without ever exceeding it. Both curves are formula-driven and bounded (growth × phase^exponent, with no table). They climb freely up to tier 15, then bend onto a ceiling they approach without ever reaching: ×30 for density, ×24 for frequency. Every tier up to 15, and therefore every row of the table below, is unchanged.

PhaseTable · mobcap(phase) = 0.9153 × phase^1.1, frequency(phase) = 1.0667 × phase^1.0
Phasemobcap(phase)frequency(phase)
00.00.0
10.921.07
55.385.33
1011.5210.67
1518.0116.0

The mob-cap follows a slightly convex curve (exponent 1.1) while the frequency is near-linear (exponent 1.0): beyond phase 15 both keep climbing, but towards their ceiling (×30 and ×24), which they never reach.

Strict restriction. onlyPlainZombie = true by default: any other hostile specimen (skeleton, creeper, husk, drowned, spider, zombie villager, zombified piglin) is cancelled at spawn, in every phase.

Extrapolation confirmed. At tier 15, the mob-cap climbs up to ×18.01 the vanilla cap; beyond that, the curve closes in on its ×30 bound (phaseMobcapCeiling).

Configuration

WorldSpawnConfig
FieldDescriptionDefault
nightSpawnEnabledEnables phased night spawning.true
onlyPlainZombieCancels any hostile that is not a plain zombie.true
spawnMaxExtraPassesMaximum number of extra spawn passes per chunk per tick.512
blockBabyZombiesPrevents baby zombies from spawning.true
blockDrownedPrevents drowned from spawning, including vanilla's conversion after 30 seconds under water: the drowned it produces is discarded on load. At shipped settings, drowning kills the zombie well before that delay.true