Size/stat variation and random effects
Each zombie carries stable random "genes", drawn the moment it appears: size, speed, damage, health, leap power. The seed is derived from its UUID (size/speed/damage/health share one draw, leap has its own salt), so it is fixed for the entire duration of the record and stable across reloads, no two zombies are ever fully identical, but a given individual no longer varies once born.
| Attribute | Min | Max |
|---|---|---|
| Size (SCALE) | 0.85 | 1.25 |
| Speed | 0.9 | 1.2 |
| Damage | 0.85 | 1.3 |
| Max health | 0.9 | 1.2 |
| Leap | 0.85 | 1.2 |
A safety floor of 0.05 is applied to size and speed so that no draw produces an invisible or fully frozen zombie. A "giant" (size ~1.25) potentially breaks more blocks overhead to carve itself a path.
Beneficial potion effects at spawn
In legacy mode, roughly 25% of zombies receive, upon appearance, a permanent beneficial potion effect (infinite duration, saved), amplifier from 0 to 3, drawn from an eight-entry pool: Speed, Strength, Resistance, Jump Boost, Haste, Health Boost, Absorption, and an exclusive custom effect named LEAP.
Two deliberate exclusions. Fire Resistance is kept out of the pool so daylight burning stays a real constraint at the early tiers: past tier 5 they become immune to it anyway. Regeneration is kept out too, but for a technical reason: the base game refuses it to the undead, so it would have done nothing.
The LEAP effect
Multiplies the horizontal component of the leap by 1.0 + 0.35 × (amplifier + 1)
and widens its trigger range (2.5 to 8.0 blocks). Unlike Jump Boost (vanilla, which makes it jump
higher), LEAP makes it leap farther, and the two effects stack on the same zombie.
Configuration
| Field | Description | Default |
|---|---|---|
| randomEffectChance | Chance that a zombie receives a beneficial effect at spawn. | 0.25 |
| randomEffectMaxAmplifier | Maximum amplifier. | 3 |
| leapEffectPerLevel | Leap range bonus per level of LEAP. | 0.35 |
| leapMinRange / leapMaxRange | Leap trigger range (fields live in CombatMoveConfig, not WorldSpawnConfig). | 2.5 / 8.0 |
| safeDropBlocks | Drop deemed safe without a detour, see descent (field lives in CombatMoveConfig). | 3 |