Increasing maximum amount of NPC's

A lot of servers are starting to use OSRS spawn dumps + have their own custom NPC spawns/instances, issue is most 317 clients are still only allowing 16k or 32k npcs, this is how to increase it too 65k(what OSRS currently uses)

Client side:

Change npc array size

npcs = new Npc[65536];

Find the following still in Client.java

 = new Npc();

Above it change the while() loop/break + the first bit read to match

while (stream.bitsRemaining(i) >= 28) {
    int k = stream.readBits(16);
    if (k == 65535) {
       break;
    }
    if (npcs[k] == null) {
       npcs[k] = new Npc();
    }

Server Side

Again change your npc collection to support 65k npc's

Find where your npc update packet sends the npc index, below is for Xeros

public void addNewNPC(NPC npc, Stream str, Stream updateBlock, boolean flag) {
    int id = npc.getIndex();
    npcList[npcListSize++] = npc;
    str.writeBits(14, id);

Change the writeBits(14, id) too writeBits(16, id);

Next server side you'll want to find the following

writeBits(14, 16383);

Change this too

writeBits(16, 65535);

And this should be it, you can now properly support 65k npcs. The examples used here are for Xeros, but it shouldn't be hard to replicate for other bases

Edited April 20, 20241 yr by Adam