NPC Class

WorldObject
  └── Creature
      └── Npc
          ├── Attackable (Monsters)
          ├── Monster
          ├── Guard
          ├── Merchant
          ├── Teleporter
          └── ... (50+ specialized types)

Attackable monster = (Attackable) npc;
monster.addDamageHate(player, 0, 1000); // Add hate
boolean isAggressive = monster.isAggressive();

Guard guard = new Guard(template);
guard.setIsAutoAttackable(false);

Merchant merchant = new Merchant(template);
merchant.showBuyWindow(player, 0);

Teleporter teleporter = new Teleporter(template);
teleporter.showTeleportList(player);

// Get NPC template
NpcTemplate template = NpcData.getInstance().getTemplate(30001);

// Create spawn
Spawn spawn = new Spawn(template);
spawn.setLocation(x, y, z, heading);
spawn.setRespawnDelay(60); // 60 seconds

// Spawn the NPC
Npc npc = spawn.doSpawn();

public class CustomNpc extends Npc {
    public CustomNpc(NpcTemplate template) {
        super(template);
    }
    
    @Override
    public void showChatWindow(Player player) {
        NpcHtmlMessage html = new NpcHtmlMessage(getObjectId());
        html.setFile(player, "data/html/custom/welcome.htm");
        html.replace("%name%", player.getName());
        player.sendPacket(html);
    }
    
    @Override
    public void onBypassFeedback(Player player, String command) {
        if (command.equals("givereward")) {
            player.addItem("Reward", 57, 10000, this, true);
        }
    }
}

// In quest script
public class MyQuest extends Quest {
    private static final int QUEST_NPC = 30001;
    
    @Override
    public String onTalk(Npc npc, Player player) {
        QuestState qs = getQuestState(player, true);
        
        if (npc.getId() == QUEST_NPC) {
            if (qs.isStarted()) {
                return "quest_running.htm";
            } else {
                return "quest_start.htm";
            }
        }
        return null;
    }
    
    @Override
    public String onKill(Npc npc, Player killer, boolean isSummon) {
        QuestState qs = getQuestState(killer, false);
        if (qs != null && qs.isCond(1)) {
            qs.setCond(2, true);
        }
        return null;
    }
}

public class RaidBoss extends GrandBoss {
    private static final int MINION_ID = 20001;
    
    public RaidBoss(NpcTemplate template) {
        super(template);
    }
    
    @Override
    protected void onDeath(Creature killer) {
        // Despawn all minions
        Map<Integer, Npc> summons = getSummonedNpcs();
        if (summons != null) {
            for (Npc minion : summons.values()) {
                minion.deleteMe();
            }
        }
        
        // Handle rewards
        if (killer.getActingPlayer() != null) {
            Player player = killer.getActingPlayer();
            // Give rewards to party/raid
        }
        
        super.onDeath(killer);
    }
    
    // Spawn minions when HP drops
    @Override
    public void reduceCurrentHp(double damage, Creature attacker, 
                                Skill skill, boolean isDOT) {
        double hpRatio = getCurrentHp() / getMaxHp();
        
        if (hpRatio < 0.5 && getScriptValue() == 0) {
            setScriptValue(1); // Mark as triggered
            spawnMinions();
        }
        
        super.reduceCurrentHp(damage, attacker, skill, isDOT);
    }
    
    private void spawnMinions() {
        for (int i = 0; i < 5; i++) {
            addMinion(MINION_ID, false);
        }
    }
}

// Set custom AI
Npc npc = spawn.doSpawn();
npc.setAI(new CustomAI(npc));

// Custom AI class
public class CustomAI extends NpcAI {
    public CustomAI(Npc npc) {
        super(npc);
    }
    
    @Override
    protected void onEvtAttacked(Creature attacker, int damage) {
        // Custom attack response
        if (getRandom(100) < 30) {
            // 30% chance to teleport when attacked
            Npc npc = (Npc) _actor;
            npc.teleToLocation(npc.getSpawn().getLocation());
        }
        super.onEvtAttacked(attacker, damage);
    }
}