zHunters Personal Boss Fight

zHunters Personal Boss Fight is a multiplayer-focused mod for Minecraft 1.20.1 Fabric that makes boss fights and other configured entity encounters fairer by rewarding players based on their participation instead of who lands the final hit.

The mod tracks each player's damage contribution during a fight and gives every qualifying participant their own personal loot. It can also distribute compatible boss-kill advancements to all players who meet the participation requirement.

Features

• Personal Boss Loot — Qualified players receive their own personal copy of the managed loot instead of competing for a single drop pile.
• Damage-Based Participation — By default, players must contribute at least 15% of the entity's maximum health to qualify for the fight. This value can be changed in the configuration.
• Independent Fight Tracking — Every entity instance is tracked separately, allowing multiple identical bosses or entities to be fought simultaneously in different locations or dimensions without mixing player contributions.
• Projectile Damage Tracking — Supported player-owned projectiles can have their damage attributed to the player who caused the attack.
• Personal Boss-Kill Advancements — When enabled, the mod automatically searches for compatible minecraft:player_killed_entity advancements for the entity types configured in the boss list and can grant them to every qualifying participant.
• Multiple Advancements — If a configured entity has multiple compatible boss-kill advancements, all matching criteria can be granted to each qualifying participant.
• Existing Advancement Protection — Players who already completed an advancement do not receive duplicate progress. They still receive their personal loot normally when participating in future fights.
• Config-Driven Entity List — The bosses list determines which entities are managed by the mod. Despite the name, the system can be used with any entity you choose, not only traditional bosses.
• Automatic Advancement Discovery — No separate advancement list is required for normal use. When an entity is added to the configuration, the mod checks the server's loaded advancements for compatible kill criteria for that entity.
• Persistent Rewards — Pending item rewards remain saved across reconnects and server restarts.
• Excluded Drops — Specific items can be excluded from personal distribution on a per-entity basis when certain drops should remain shared.
• Ender Dragon Support — The Ender Dragon receives special handling for its Dragon Egg, allowing qualifying players to receive their own personal reward.
• Persistent Dragon Egg Progress — A player only receives the personal Dragon Egg reward once, while continuing to receive normal personal loot from future eligible fights.
• Safe Advancement Processing — Advancement discovery is performed when the server starts and after successful data-pack reloads rather than during every game tick or every boss death.

How It Works

When a configured entity takes damage, the mod records the contribution of each participating player for that specific entity.

When the entity dies, the mod checks which players reached the configured participation threshold.

For example:

Entity Maximum Health: 10,000
Required Participation: 15%

Player A → 4,000 damage → Qualified
Player B → 2,000 damage → Qualified
Player C → 1,000 damage → Not Qualified

Player A and Player B would each receive their own personal copy of the managed loot.

The system does not divide loot proportionally according to damage. Once a player reaches the configured threshold, they qualify for the full personal reward.

Boss-Kill Advancements

Boss-kill advancements are handled separately from loot.

For example, if the following entity is configured:

minecells:concierge

the mod checks the advancements loaded by the server for compatible:

minecraft:player_killed_entity

criteria targeting:

minecells:concierge

If multiple compatible advancements exist for the same entity, all matching criteria can be granted to every qualifying participant.

If a player already has one of those advancements, their existing progress remains unchanged. The player still receives their personal loot normally.

The system intentionally avoids automatically completing advancements that contain additional requirements that the player may not have actually fulfilled. This prevents the mod from bypassing custom advancement conditions such as specific weapons, damage types, locations, effects, or other requirements.

Multiplayer Boss Fights

Each fight is tracked using the individual entity instance rather than only the entity type.

For example:

Concierge A
→ Alice
→ Bob

Concierge B
→ Carlos
→ David

Even though both entities are:

minecells:concierge

their participation data remains completely separate.

This allows the same boss or entity to be fought at the same time in different locations or dimensions without mixing damage contribution, loot, or fight data.

Configuration

The configuration file is:

.minecraft/config/zhunters_personal_boss_fight.json

Important options include:

• minimumDamageFraction — Required fraction of the entity's maximum health. The default value 0.15 means 15%.
• awardBossKillAdvancements — Enables or disables automatic distribution of compatible boss-kill advancements.
• debugLogging — Enables detailed diagnostic logging when needed.
• bosses — The list of entity IDs controlled by the mod. Add new entities here to make them part of the Personal Boss Fight system.
• excludedItemsByBoss — Defines specific drops that should remain excluded from personal distribution.

The bosses list is the source of truth for the mod.

You can add any entity ID you want, including bosses from other mods, vanilla entities, or even normal mobs.

For example:

"bosses": [
    "minecells:concierge",
    "minecraft:wither",
    "minecraft:warden",
    "twilightforest:hydra"
]

When a new entity is added to this list, it is automatically included in the damage tracking and personal loot system.

The same configured entity is also considered when building the automatic advancement index.

Loot Rewards

Qualified players receive their own copy of the managed loot.

For example, if a configured entity normally drops:

1x Boss Weapon
2x Boss Material
5x Boss Token

and three players qualify for the fight, each player can receive:

Player A
→ 1x Boss Weapon
→ 2x Boss Material
→ 5x Boss Token

Player B
→ 1x Boss Weapon
→ 2x Boss Material
→ 5x Boss Token

Player C
→ 1x Boss Weapon
→ 2x Boss Material
→ 5x Boss Token

The reward is not split between the players.

Pending Rewards

If a player's inventory cannot hold the complete reward, the remaining items are stored as pending rewards.

Pending rewards are persistent and can survive:

• Leaving the server
• Reconnecting
• Server restarts

This prevents qualified players from losing rewards simply because their inventory was full when the entity was defeated.

Ender Dragon

The Ender Dragon receives special handling because of its unique Dragon Egg behavior.

Instead of allowing the normal global Dragon Egg reward to determine who receives it, the mod can provide a personal Dragon Egg reward to qualifying participants.

A player can receive the personal Dragon Egg reward once.

Future Ender Dragon fights can still provide that player with their normal personal loot.

Compatible Mods

The mod is designed to work with any entity registered by another mod as long as its entity ID is added to the configuration.

The default configuration includes entities from:

• Mine Cells
• AdventureZ
• Aquamirae
• Minecraft Comes Alive Reborn
• Marium's Soulslike Weaponry
• The Twilight Forest

The mod can also manage vanilla entities such as:

• Wither
• Warden
• Ender Dragon

Installation

Install zHunters Personal Boss Fight on the server and client as required by your setup.

Launch the game once to generate:

.minecraft/config/zhunters_personal_boss_fight.json

Add or remove entity IDs from the bosses list according to the bosses or entities you want the mod to manage.

No additional advancement configuration is required for normal use.

Compatibility

Minecraft: 1.20.1
Mod Loader: Fabric
Java: 17+

The mod is designed to work alongside entities, loot tables, and advancement systems provided by other mods without requiring those mods to directly support zHunters Personal Boss Fight.

Credits

Created by zClashTM.

License

zHunters Personal Boss Fight is licensed under the MIT License.