# l2j-gameserver

> Implements L2J gameserver architecture, networking, and player interactions for the Tales of Aden private server.
Use when: writing game logic, adding handlers, creating packets, or modifying core server behavior

- Author: valeriybaranyshyn-pixel
- Repository: valeriybaranyshyn-pixel/Tales-of-Aden
- Version: 20260202145225
- Stars: 0
- Forks: 0
- Last Updated: 2026-02-06
- Source: https://github.com/valeriybaranyshyn-pixel/Tales-of-Aden
- Web: https://mule.run/skillshub/@@valeriybaranyshyn-pixel/Tales-of-Aden~l2j-gameserver:20260202145225

---

---
name: l2j-gameserver
description: |
  Implements L2J gameserver architecture, networking, and player interactions for the Tales of Aden private server.
  Use when: writing game logic, adding handlers, creating packets, or modifying core server behavior
allowed-tools: Read, Edit, Write, Glob, Grep, Bash
---

# L2J GameServer Skill

The GameServer is the core gameplay engine handling all player actions, NPCs, combat, events, and world state. It uses a layered architecture: NIO network → packet handlers → game logic handlers → entity model → database.

## Quick Start

### Register a New Skill Handler

```java
// 1. Create handler implementing ISkillHandler
public class MySkill implements ISkillHandler {
    private static final L2SkillType[] SKILL_IDS = { L2SkillType.MY_TYPE };
    
    @Override
    public void useSkill(Creature activeChar, L2Skill skill, L2Object[] targets) {
        for (L2Object obj : targets) {
            if (!(obj instanceof Creature)) continue;
            Creature target = (Creature) obj;
            // Apply skill logic
            int damage = (int) Formulas.calcPhysDam(activeChar, target, skill, shld, crit, ss);
            target.reduceCurrentHp(damage, activeChar, skill);
        }
    }
    
    @Override
    public L2SkillType[] getSkillIds() { return SKILL_IDS; }
}

// 2. Register in SkillHandler constructor
registerSkillHandler(new MySkill());
```

### Create a Voiced Command

```java
// Implement IVoicedCommandHandler in handler/voicedcommandhandlers/
public class MyCommand implements IVoicedCommandHandler {
    private static final String[] COMMANDS = { "mycommand" };
    
    @Override
    public boolean useVoicedCommand(String command, Player activeChar, String target) {
        activeChar.sendMessage("Command executed!");
        return true;
    }
    
    @Override
    public String[] getVoicedCommandList() { return COMMANDS; }
}

// Register conditionally in VoicedCommandHandler
if (Config.ENABLE_MY_COMMAND) {
    registerHandler(new MyCommand());
}
```

## Key Concepts

| Concept | Usage | Example |
|---------|-------|---------|
| Singleton Manager | Thread-safe lazy init via inner class | `SingletonHolder._instance` |
| Handler Pattern | Type-dispatch via ordinal/hashCode | `_datatable.put(type.ordinal(), handler)` |
| Packet Template | read() → readImpl(), run() → runImpl() | `L2GameClientPacket` |
| AI State Machine | Intention → Event → State change | `setIntention(ATTACK)` → `onEvtThink()` |
| Skill Hash | Fast lookup: `skillId * 256 + level` | `SkillTable.getSkillHashCode()` |

## Common Patterns

### Schedule a Task

**When:** Delayed or periodic execution needed

```java
// One-time delayed task
ThreadPool.schedule(() -> {
    player.sendMessage("5 seconds passed!");
}, 5000);

// Periodic task
ThreadPool.scheduleAtFixedRate(() -> {
    broadcastStatus();
}, 0, 60000); // Every 60 seconds
```

### Send Packet to Player

**When:** Client needs visual/data update

```java
// Direct send
player.sendPacket(new MagicSkillUse(activeChar, target, skillId, level, hitTime, reuseDelay));

// Broadcast to nearby
activeChar.broadcastPacket(new Attack(activeChar, target, damage, miss, crit, shld));
```

## See Also

- [patterns](references/patterns.md) - Singleton, handler, and packet patterns
- [workflows](references/workflows.md) - Adding features, debugging, testing

## Related Skills

When working with L2J GameServer:
- See the **java** skill for Java 11 conventions and L2J coding patterns
- See the **ant** skill for building the server JAR
- See the **mariadb** skill for database schema and queries
- See the **ai-system** skill for L2SummonAI and creature AI implementation
- See the **packet-protocol** skill for L2 binary protocol details
- See the **skill-system** skill for L2Skill data model and effects
- See the **pvp-events** skill for TvT, CTF, DeathMatch implementation