Entity Goal System

Overview

The Goal System is the core AI behavior framework in Minecraft, controlling how entities make decisions and execute actions. It is divided into two main components: goalSelector (daily behavior goals) and targetSelector (attack/target goals).

Core Concepts

goalSelector

Manages daily behaviors like wandering, attacking, breeding, etc. Lower priority numbers execute first.

Priority	Typical Use
0	Critical (e.g., float when in water)
1-2	Combat (e.g., melee attack)
3-4	Movement (e.g., random wander)
5+	Idle behaviors

targetSelector

Manages target selection and tracking, used for hostile mobs to find and track attack targets.

Lifecycle Methods

Goals have a clear lifecycle:

Stage	Method	Description
Can Use	canUse()	Check if goal can be activated
Start	start()	Called when goal starts executing
Tick	tick()	Called each tick while goal is active
Can Continue	canContinueToUse()	Check if goal should continue
Stop	stop()	Called when goal stops

Common Goal Classes

Movement Goals

Goal Class	Description
FloatGoal	Float in water
RandomStrollGoal	Random wandering
LookAtPlayerGoal	Look at player
MoveTowardsTargetGoal	Move toward target
BreedGoal	Find mate and breed

Combat Goals

Goal Class	Description
MeleeAttackGoal	Melee attack target
RangedAttackGoal	Ranged attack
HurtByTargetGoal	Attack what hurt it

Usage Examples

// Add goal
const FloatGoal = Java.loadClass("net.minecraft.world.entity.ai.goal.FloatGoal");
mob.goalSelector.addGoal(0, new FloatGoal(mob));

// Add target goal
const NearestAttackableTargetGoal = Java.loadClass("net.minecraft.world.entity.ai.targeting.NearestAttackableTargetGoal");
mob.targetSelector.addGoal(0, new NearestAttackableTargetGoal(mob, Player.class, true));

Notes

• Goal priority: Lower number = higher priority
• Only one goal per priority level in each selector
• Use removeGoal to clear goals
• For 1.19+, consider using Brain system instead