BetterPeaceMode

Two additional peace-oriented game modes for Minecraft Java Edition: Better Peace and Real Peace.

Vanilla Peaceful removes hostile mobs entirely, and vanilla Easy/Hard leave every hostile mob free to start fights. BetterPeaceMode fills the space between those two extremes with two selectable modes:

Vanilla Peaceful, plus one rule: friendly mobs no longer attack each other. A fox stops hunting chickens, wolves stop hunting sheep, and any other animal-versus-animal predation is suppressed. Player-versus-mob conflict is untouched, so the world still behaves like the Peaceful everyone knows.

Better Peace, plus hostile mobs are allowed back:

• Hostile mobs spawn normally, at the difficult spawn density, which means the world stays populated the way a Hard-difficulty world does.
• No hostile entity starts a fight. Zombies, skeletons, creepers, spiders, endermen and piglins ignore players, villagers, animals and each other while they are unprovoked.
• The ender dragon and the wither are exempt: they remain hostile.
• Provocation creates a one-to-one grudge. The moment an entity is actually hit, it remembers exactly who hit it and may retaliate against that entity and only that entity, for a bounded window (600 ticks by default). Hitting any entity therefore starts a fight.
• Every entity can fight back. Hostile mobs already know how; cows, sheep, chickens, villagers and every other peaceful mob are given the ability the first time they are provoked. Mobs that ship an attack-damage value keep it, and the rest are assigned one by size (1 for small, 2 for medium, 3 for large), scaled by retaliationDamageMultiplier.
• Provoked entities call for help. By default the caller spawns up to 7 helpers of its own type within 16 blocks, giving a hate group of 8 including itself. While any member of the group is still alive it keeps topping the group up on a randomised 10-30 s schedule, reaching twice the radius, and replenishment arrivals carry randomised Speed II-V and Strength I-III. Once every member has died the group is dropped and the calls stop.
• One group per enemy, shared by every race. A hate group belongs to the entity being fought, not to the caller: any mob provoked by the same attacker joins the fight that already exists instead of opening a second one. Four zombies that a player hits in the same brawl therefore form one group of four plus seven helpers, not four groups of eight.
• The area around a call has an entity budget. Before spawning helpers the mod counts the mobs in a chunk-aligned area around the caller (one chunk by default, or the whole server simulation distance if you prefer) and refuses to add more once the configured maximum is reached. A saturated area - a full animal pen, a village, a mob farm - simply stops producing helpers until something dies.
• Super reinforcements (optional). With superReinforcements enabled every helper arrives with double maximum health and indefinite Resistance, Regeneration and Fire Resistance on top of the normal replenishment buffs. Vanilla refuses Regeneration on undead helpers, so zombies and skeletons keep the other two.
• Parents guard their young. Any adult of the same species within 16 blocks of a baby hates whatever living entity comes within 4 blocks of that baby, and attacks it - a cow will charge the wolf that walked up to its calf. Siblings and herd mates are never treated as threats, and creative or spectator players are ignored so a parent cannot lock onto someone it can never hurt.
• Nether mobs stay calm outside the Nether and do not mutate: piglins do not turn into zombified piglins and hoglins do not turn into zoglins, and while they are away from home they will not start a fight - though they will still retaliate if attacked.
• Hard difficulty's zombie reinforcement swarm is disabled, so combat stays strictly one-to-one.
• The player keeps the Peaceful regeneration rate (1 HP and 1 saturation per second while hurt), which the Hard difficulty alone would not provide.
• Attacks that never go through AI target selection are covered too: a slime or a pufferfish hurts whatever it touches, and those contact hits are cancelled outright while the creature is unprovoked - no damage, no knockback, no invulnerability window, and no grudge.

config/betterpeacemode.json is created on first launch:

{
  "gameMode": "VANILLA",
  "friendlyPeace": false,
  "realPeace": false,
  "keepBossHostile": true,
  "hostilesIgnoreEachOther": true,
  "crossDimensionCalm": true,
  "aggroDurationTicks": 600,
  "universalRetaliation": true,
  "retaliationDamageMultiplier": 1.0,
  "reinforcementsEnabled": true,
  "reinforcementCount": 7,
  "reinforcementRadius": 16.0,
  "autoReinforce": true,
  "autoReinforceMaxSeconds": 30,
  "autoReinforceRadiusMultiplier": 2.0,
  "areaLimitEnabled": true,
  "areaLimitRadiusChunks": 1,
  "areaLimitUseSimulationDistance": false,
  "areaLimitMaxEntities": 24,
  "superReinforcements": false,
  "babyGuardEnabled": true
}

Requires permission level 2 (gamemasters) or higher, so single-player worlds and server operators both work.

In single-player the same settings are available from an in-game screen, opened with the mod's key binding (default B). On a dedicated server the client screen edits the local config, so operators should use the command or the server's config file instead.

The mode is expressed as a small set of vanilla entry points rather than as a rewrite of mob AI:

• Target acquisition (Mob#setTarget, plus the four subclasses that override it - fox, creeper, enderman and zombified piglin) is gated, which stops a mob from ever starting a pursuit.
• Damage application (LivingEntity#hurtServer) is gated, which cancels friendly-versus-friendly and unprovoked hits before any of vanilla's hurt bookkeeping runs, and records the one-to-one grudge in both directions for the hits that do land.
• A once-per-second server sweep re-checks live targets, pins the difficulty for the active mode, keeps Nether mobs from mutating, prunes expired grudges and bounds the cost to a fixed budget. A faster pass on the same sweep drives the baby guard.
• The grudge itself is kept by the mod rather than by vanilla's lastHurtByMob, because vanilla forgets that field after 100 ticks and would silently cap the configured window at five seconds.
• SpearUseGoal#tick is guarded against a null target. 1.21.11 hands zombies and zombified piglins that goal, and vanilla's MeleeAttackGoal#stop clears the target when it is displaced, which crashes the server when it happens to a zombie that is fighting a creative-mode player.
• Zombie reinforcements are pinned to zero so no fight can escalate into a swarm.

$env:JAVA_HOME = "<a JDK 25>"      # Loom 1.18 needs JDK 25 to run
.\gradlew.bat build                # the mod itself still targets Java 21

Output: build/libs/BetterPeaceMode-v26.0-Alpha.4-JE-1.21.11-Fabric.jar.

• Minecraft 1.21.11, Fabric Loader 0.19.3+ and Fabric API (the command surface uses the Fabric command callback).
• Client and dedicated server both work; the rules are installed from the common entry point.
• Works alongside other mods. The patches touch only well-known vanilla methods and become no-ops when the selected mode is vanilla.

License: Apache-2.0

GitHub@NDBlockConnect