Spawn Management

Overview

The spawn management system handles NPC spawning, respawning, territory-based spawning, and spawn data persistence in L2J Mobius Chronicle 4. Key Classes:

org.l2jmobius.gameserver.model.Spawn - Individual spawn instance
org.l2jmobius.gameserver.data.xml.SpawnData - XML spawn loader (singleton)
org.l2jmobius.gameserver.data.SpawnTable - Central spawn registry (singleton)
org.l2jmobius.gameserver.managers.DayNightSpawnManager - Day/night spawn control

Spawn Class

Location: org.l2jmobius.gameserver.model.Spawn Represents a single NPC spawn point with respawn mechanics.

Constructor

// By template
public Spawn(NpcTemplate template) throws ClassNotFoundException, NoSuchMethodException

// By NPC ID
public Spawn(int npcId) throws ClassNotFoundException, NoSuchMethodException

Example:

Spawn spawn = new Spawn(20001); // Orc Fighter
spawn.setXYZ(-84080, 243298, -3728);
spawn.setAmount(5);
spawn.setRespawnDelay(60); // 60 seconds
spawn.init();

Core Properties

_maximumCount

int

Maximum number of NPCs this spawn manages.

public void setAmount(int amount)
public int getAmount()

_currentCount

int

Current number of spawned NPCs (read-only).

_respawnMinDelay

int

Minimum respawn delay in milliseconds.

public int getRespawnMinDelay()

_respawnMaxDelay

int

Maximum respawn delay in milliseconds.

public int getRespawnMaxDelay()

_doRespawn

boolean

Whether automatic respawning is enabled.

public boolean isRespawnEnabled()
public void stopRespawn()
public void startRespawn()

Key Methods

Initialization

init

int

Initializes the spawn and creates all NPCs.

public int init()

Process:

Spawns NPCs until _currentCount reaches _maximumCount
Sets _doRespawn based on respawn delay (enabled if > 0)

Returns: Number of NPCs spawned

doSpawn

Npc

Spawns a single NPC instance.

public Npc doSpawn()
public Npc doSpawn(boolean isSummonSpawn)

Parameters:

isSummonSpawn - If true, shows summon animation

Returns: Spawned Npc instance or null on failureProcess:

Creates NPC from template using reflection
Sets instance ID
Calculates spawn position (random if territory-based)
Corrects Z coordinate using GeoEngine
Sets HP/MP to maximum
Sets random or fixed heading
Spawns NPC into world
Increments _currentCount

Respawn Control

decreaseCount

void

Handles NPC death and schedules respawn.

public void decreaseCount(Npc oldNpc)

Process:

Decrements _currentCount
Removes NPC from spawn list
If respawn enabled and under max count:
- Increments _scheduledCount
- Schedules respawn via RespawnTaskManager
- Uses random delay if _respawnMaxDelay differs from _respawnMinDelay

respawnNpc

void

Immediately respawns an NPC.

public void respawnNpc(Npc oldNpc)

Reinitializes the NPC at spawn location (used by RespawnTaskManager).

Location Management

setXYZ

void

Sets spawn coordinates (inherited from Location).

public void setXYZ(int x, int y, int z)

setLocation

void

Sets spawn location from Location object.

public void setLocation(Location loc)

setSpawnTerritory

void

Sets spawn territory for random position spawning.

public void setSpawnTerritory(NpcSpawnTerritory territory)

When territory is set, NPCs spawn at random positions within the territory boundaries.

isTerritoryBased

boolean

Checks if spawn uses territory-based positioning.

public boolean isTerritoryBased()

Returns: true if territory is set and X/Y coordinates are 0

Respawn Timing

setRespawnDelay

void

Sets respawn delay with optional randomization.

public void setRespawnDelay(int delay)
public void setRespawnDelay(int delay, int randomInterval)

Parameters:

delay - Base respawn delay in seconds
randomInterval - Random variance in seconds (±)

Example:

spawn.setRespawnDelay(60, 20);
// Respawns between 40-80 seconds

Converted to milliseconds internally:

_respawnMinDelay = (delay - randomInterval) * 1000
_respawnMaxDelay = (delay + randomInterval) * 1000

getRespawnDelay

int

Gets average respawn delay.

public int getRespawnDelay()

Returns: Average of min and max delays in milliseconds

hasRespawnRandom

boolean

Checks if respawn has random component.

public boolean hasRespawnRandom()

Other Properties

setChaseRange

void

Sets maximum chase distance for monsters.

public void setChaseRange(int chaseRange)
public int getChaseRange()

NPCs won’t pursue targets beyond this range from spawn point.

setRandomWalking

void

Enables/disables random walking.

public void setRandomWalking(boolean value)
public boolean getRandomWalking()

setName

void

Sets spawn identifier name.

public void setName(String name)
public String getName()

Spawned NPC Tracking

getSpawnedNpcs

Deque<Npc>

Gets all NPCs currently spawned by this spawn.

public Deque<Npc> getSpawnedNpcs()

Returns: Thread-safe deque of spawned NPCs

getLastSpawn

Npc

Gets the most recently spawned NPC.

public Npc getLastSpawn()

SpawnData

Location: org.l2jmobius.gameserver.data.xml.SpawnData Loads and manages NPC spawns from XML files.

Singleton Pattern

SpawnData spawnData = SpawnData.getInstance();

XML Spawn Format

File Location: data/spawns/

<?xml version="1.0" encoding="UTF-8"?>
<list enabled="true">
    <spawn name="town_gludio">
        <!-- Fixed position spawn -->
        <npc id="30001" x="-80826" y="149775" z="-3043" 
             heading="0" respawnDelay="60" />
        
        <!-- Multiple count spawn -->
        <npc id="20001" count="5" x="-84080" y="243298" z="-3728"
             respawnDelay="300" respawnRandom="60" />
        
        <!-- Territory-based spawn -->
        <territory shape="NPoly" minZ="-4000" maxZ="-3000">
            <node x="-85000" y="240000" />
            <node x="-83000" y="240000" />
            <node x="-83000" y="245000" />
            <node x="-85000" y="245000" />
        </territory>
        
        <npc id="20002" count="10" zone="town_gludio" 
             respawnDelay="180" />
        
        <!-- Day/night spawn -->
        <npc id="20010" x="-80000" y="150000" z="-3000"
             periodOfDay="night" respawnDelay="60" />
        
        <!-- Custom AI parameters -->
        <AIData>
            <disableRandomWalk>true</disableRandomWalk>
            <disableRandomAnimation>true</disableRandomAnimation>
        </AIData>
        <npc id="30100" x="-80000" y="150000" z="-3000" />
    </spawn>
</list>

Key Methods

addNewSpawn

void

Adds a new spawn and persists to XML.

public synchronized void addNewSpawn(Spawn spawn)

Process:

Adds to SpawnTable
Determines XML file based on world tile coordinates
Appends spawn entry to existing file or creates new one
Creates directory data/spawns/Others/ if needed

deleteSpawn

void

Removes spawn from table and XML file.

public synchronized void deleteSpawn(Spawn spawn)

Process:

Removes from SpawnTable
Locates XML file
Removes matching spawn entry
Deletes file if it becomes empty

getSpawnFile

String

Gets the XML file path for a spawn template ID.

public String getSpawnFile(int templateId)

Territory Shapes

Supported Shapes:

NPoly - N-sided polygon (3+ vertices)

<territory shape="NPoly" minZ="-4000" maxZ="-3000">
    <node x="-85000" y="240000" />
    <node x="-83000" y="240000" />
    <node x="-83000" y="245000" />
</territory>

Cuboid - Rectangular box (2 vertices)

<territory shape="Cuboid" minZ="-4000" maxZ="-3000">
    <node x="-85000" y="240000" />
    <node x="-83000" y="245000" />
</territory>

Cylinder - Circular area (1 center point + radius)

<territory shape="Cylinder" minZ="-4000" maxZ="-3000" rad="1000">
    <node x="-84000" y="242500" />
</territory>

Banned Territories

Exclude areas within spawn territories:

<spawn name="hunting_ground" zone="forest_area">
    <territory shape="NPoly" minZ="-4000" maxZ="-3000">
        <!-- Main spawn area -->
        <node x="-90000" y="240000" />
        <node x="-80000" y="240000" />
        <node x="-80000" y="250000" />
        <node x="-90000" y="250000" />
    </territory>
    
    <banned_territory shape="Cylinder" minZ="-4000" maxZ="-3000" rad="500">
        <!-- Don't spawn near this point -->
        <node x="-85000" y="245000" />
    </banned_territory>
    
    <npc id="20001" count="20" zone="forest_area" />
</spawn>

SpawnTable

Location: org.l2jmobius.gameserver.data.SpawnTable Central registry for all active spawns.

Singleton Pattern

SpawnTable spawnTable = SpawnTable.getInstance();

Key Methods

getSpawnTable

Map<Integer, Set<Spawn>>

Gets complete spawn table.

public Map<Integer, Set<Spawn>> getSpawnTable()

Returns: Map of NPC ID → Set of spawns

getSpawns

Set<Spawn>

Gets all spawns for an NPC ID.

public Set<Spawn> getSpawns(int npcId)

Returns: Set of spawns or empty set if none

getSpawnCount

int

Counts spawns for an NPC.

public int getSpawnCount(int npcId)

getAnySpawn

Spawn

Gets any spawn for an NPC ID.

public Spawn getAnySpawn(int npcId)

Returns: First spawn found or null

addSpawn

void

Registers a spawn.

public void addSpawn(Spawn spawn)

Creates new spawn set if needed (thread-safe).

removeSpawn

void

Unregisters a spawn.

public void removeSpawn(Spawn spawn)

Removes spawn set if it becomes empty.

Usage Examples

Create and Initialize Spawn

try {
    // Create spawn for Orc Fighter (20001)
    Spawn spawn = new Spawn(20001);
    
    // Set location
    spawn.setXYZ(-84080, 243298, -3728);
    spawn.setHeading(0);
    
    // Configure spawn behavior
    spawn.setAmount(5); // Spawn 5 NPCs
    spawn.setRespawnDelay(300, 60); // 240-360 seconds
    spawn.setRandomWalking(true);
    spawn.setChaseRange(1000);
    
    // Initialize and spawn NPCs
    int spawned = spawn.init();
    System.out.println("Spawned " + spawned + " NPCs");
    
} catch (Exception e) {
    e.printStackTrace();
}

Territory-Based Spawning

try {
    Spawn spawn = new Spawn(20002);
    
    // Create spawn territory
    NpcSpawnTerritory territory = ZoneManager.getInstance()
        .getSpawnTerritory("hunting_ground_1");
    
    spawn.setSpawnTerritory(territory);
    spawn.setAmount(10);
    spawn.setRespawnDelay(180);
    
    spawn.init(); // Spawns at random positions in territory
    
} catch (Exception e) {
    e.printStackTrace();
}

Day/Night Spawns

try {
    Spawn nightSpawn = new Spawn(20010); // Night monster
    nightSpawn.setXYZ(-80000, 150000, -3000);
    nightSpawn.setRespawnDelay(60);
    
    // Register as night creature (don't init directly)
    DayNightSpawnManager.getInstance().addNightCreature(nightSpawn);
    
    // Create day spawn
    Spawn daySpawn = new Spawn(20011); // Day monster
    daySpawn.setXYZ(-80000, 150000, -3000);
    daySpawn.setRespawnDelay(60);
    
    DayNightSpawnManager.getInstance().addDayCreature(daySpawn);
    
} catch (Exception e) {
    e.printStackTrace();
}

Query Spawns from Table

SpawnTable spawnTable = SpawnTable.getInstance();

// Get all Orc spawns
int orcId = 20001;
Set<Spawn> orcSpawns = spawnTable.getSpawns(orcId);

System.out.println("Found " + orcSpawns.size() + " Orc spawn points");

for (Spawn spawn : orcSpawns) {
    System.out.println("  Location: " + spawn.getX() + "," + spawn.getY() + "," + spawn.getZ());
    System.out.println("  Amount: " + spawn.getAmount());
    System.out.println("  Respawn: " + spawn.getRespawnDelay() / 1000 + "s");
}

Dynamic Spawn Creation

// Create spawn at player location
Player player = ...;

try {
    Spawn spawn = new Spawn(30001); // Guard
    spawn.setXYZ(player.getX(), player.getY(), player.getZ());
    spawn.setHeading(player.getHeading());
    spawn.setAmount(1);
    spawn.setRespawnDelay(0); // No respawn
    
    Npc npc = spawn.doSpawn();
    if (npc != null) {
        player.sendMessage("Spawned: " + npc.getName());
        
        // Add to spawn table and persist
        SpawnData.getInstance().addNewSpawn(spawn);
    }
    
} catch (Exception e) {
    player.sendMessage("Failed to spawn NPC");
}

Delete Spawn

Spawn spawn = ...; // Get spawn instance

// Despawn all NPCs
for (Npc npc : spawn.getSpawnedNpcs()) {
    npc.deleteMe();
}

// Remove from table and XML
SpawnData.getInstance().deleteSpawn(spawn);

Stop/Start Respawning

Spawn spawn = ...;

// Temporarily disable respawn
spawn.stopRespawn();

// Kill remaining NPCs (won't respawn)
for (Npc npc : spawn.getSpawnedNpcs()) {
    npc.doDie(null);
}

// Re-enable respawn later
spawn.startRespawn();
spawn.init(); // Spawn new NPCs

Random Spawn System

If enabled in configuration (RandomSpawnsConfig.ENABLE_RANDOM_MONSTER_SPAWNS):

// Monsters spawn with random offset from defined position
int randX = spawnX + Rnd.get(MIN_RANGE, MAX_RANGE);
int randY = spawnY + Rnd.get(MIN_RANGE, MAX_RANGE);

// Validated with GeoEngine
if (GeoEngine.canMoveToTarget(...) && GeoEngine.canSeeTarget(...)) {
    // Use random position
}

Requirements:

Heading must not be -1 (fixed heading disables random)
Must be monster (not NPC/quest monster)
Not in water zone
Not raid/minion/flying
Not in instance
Not in exclusion list

RespawnTaskManager - Schedules NPC respawns
DayNightSpawnManager - Manages day/night creature spawning
RaidBossSpawnManager - Handles raid boss spawns
GrandBossManager - Manages grand boss spawns
NpcPersonalAIData - Custom AI parameters per spawn
ZoneManager - Spawn territory management

Source Reference

Source: java/org/l2jmobius/gameserver/model/Spawn.java:50
Source: java/org/l2jmobius/gameserver/data/xml/SpawnData.java:62
Source: java/org/l2jmobius/gameserver/data/SpawnTable.java:33

Core

Game Models

Managers

Overview

Spawn Class

Constructor

Core Properties

Key Methods

Initialization

Respawn Control

Location Management

Respawn Timing

Other Properties

Spawned NPC Tracking

SpawnData

Singleton Pattern

XML Spawn Format

Key Methods

Territory Shapes

Banned Territories

SpawnTable

Singleton Pattern

Key Methods

Usage Examples

Create and Initialize Spawn

Territory-Based Spawning

Day/Night Spawns

Query Spawns from Table

Dynamic Spawn Creation

Delete Spawn

Stop/Start Respawning

Random Spawn System

Source Reference

Build docs developers (and LLMs) love

Core

Game Models

Managers

​Overview

​Spawn Class

​Constructor

​Core Properties

​Key Methods

​Initialization

​Respawn Control

​Location Management

​Respawn Timing

​Other Properties

​Spawned NPC Tracking

​SpawnData

​Singleton Pattern

​XML Spawn Format

​Key Methods

​Territory Shapes

​Banned Territories

​SpawnTable

​Singleton Pattern

​Key Methods

​Usage Examples

​Create and Initialize Spawn

​Territory-Based Spawning

​Day/Night Spawns

​Query Spawns from Table

​Dynamic Spawn Creation

​Delete Spawn

​Stop/Start Respawning

​Random Spawn System

​Related Systems

​Source Reference

Build docs developers (and LLMs) love

Overview

Spawn Class

Constructor

Core Properties

Key Methods

Initialization

Respawn Control

Location Management

Respawn Timing

Other Properties

Spawned NPC Tracking

SpawnData

Singleton Pattern

XML Spawn Format

Key Methods

Territory Shapes

Banned Territories

SpawnTable

Singleton Pattern

Key Methods

Usage Examples

Create and Initialize Spawn

Territory-Based Spawning

Day/Night Spawns

Query Spawns from Table

Dynamic Spawn Creation

Delete Spawn

Stop/Start Respawning

Random Spawn System

Related Systems

Source Reference