WTS WTS — Kroma: Lineage II Interlude on the latest LU4 client

[kroma-l2]

Kroma — Lineage II Interlude on LU4 Client (Latest client)

 

I'm selling this project. Here's what it actually is and what's been done.

 

This is a few months of work, most of it on the reverse engineering side. I built it because I wanted to open my own Interlude server on it. That's not happening any more — I've moved on to other projects and don't have the free time left to take it the rest of the way, so I'd rather it went to someone who will.

 

The idea was to take the modern LU4 client and make it run an Interlude version of the game. Not a reskin of an old client — the actual current client, playing Interlude, against a server I wrote. That's what this is, and it works end to end: the client boots, authenticates, connects, and you play. There are six repositories. Roughly, it splits into three kinds of work: reverse engineering the client, writing the server, and rebuilding the client's own content so it matches Interlude.

 

Fully reverse engineered

 

The client's protocol wasn't documented anywhere, so it was derived from scratch off real traffic. I built a sniffer (bypassing anticheat packet encryption) that drops into the client's binaries folder and dumps live traffic to disk, then a separate Java toolchain that decrypts those captures — login and game traffic, both directions. Everything the server knows about the protocol came out of that loop: capture, decrypt, read, implement, test against the real client.

 

On top of that there's a native x64 hook and injector in C++. It points the client at your own servers and handles its authentication and session layer, plus a few client-side stability fixes that were needed to keep it from falling over once it's talking to something that isn't the official backend. The hooking is pattern-based rather than address-based, so a client patch
doesn't automatically break it.

 

The reverse-engineering notes are in the repos — the patterns, the disassembly, the decompiled functions, what each one does and why it's hooked. That documentation is a real part of what's being sold; it's the difference between inheriting a working system and inheriting a black box.

 

The server

 

Interlude ruleset, aCis lineage, but substantially rewritten and extended to speak the LU5 client's protocol with modern features like Party matching, Offline shops or Mailbox.

The geodata has been updated according to some layout changes in LU4 cities.

There's also a separate login server handling the client's auth flow.

 

Customized client to adapt to Interlude

 

This is the part people underestimate. The retail client ships retail content — retail NPCs, retail items, retail zones, retail UI. All of that had to be reshaped.

The whole client-side pipeline is scripted: extract the retail PAKs, apply every edit from data files, rebuild, drop the result back into the game folder. 23 purpose-built C# tools, ~6,700 lines, organised into three pipelines that are guaranteed not to write over each other. There's a documented checklist for regenerating everything from scratch when a new patch drops.

The important thing is that none of it is hand-editing. Every change is a line in a data file. When the client updates, you re-run the scripts instead of redoing the work from memory.

 

All NPC / item / drop lists updated according to Interlude

 

The client's own data tables were rewritten from the real Interlude client data files — `npcname-e`, `itemname-e`, `skillname-e`, `systemmsg-e`, `npcgrp`.

That means roughly 6,470 NPC and skill name/title updates and about 4,000 Drops/Spoils rows written directly into the client's `NPCDataTable` and `SkillTable`, so the client shows Interlude names, Interlude item text, Interlude system messages, and Interlude drop and spoil lists. There are also custom NPC rows on top of that, plus 304 game action rewrites.

 

Opened the catacombs

 

In the LU4 client the catacombs and necropolises are unusable — flooded, unlit, and with holes in the geometry. All three were fixed:

• Water removed. Water exclusion volumes were placed over all 12 of them: Rifts, Apostate, Patriots, Devotion, Dark Omens, Heretics, Pilgrims, Saints, Worship, Martyr, Forbidden Path and Witch. This was more involved than it sounds — the volumes' scale is ignored at runtime, so the tool picks the best-fitting native template per hole, and nearby lakes and rivers are separate water bodies that have to be excluded individually or you get leftover water borders.
• Lights added. About 28,900 light definitions imported into the client's level files.
• Missing walls fixed. Mesh actors replaced and spawned to close the gaps in the geometry.

 

Removed the modern "slop" features from the UI

 

The LU4 client is full of things that have no business in an Interlude server, and most of them are wired into the UI. Those are stripped out:

• The assistant manager — the auto-hunt / auto-play slot on the XP bar
• Vitality*and the XP lock button
• The fatigue system — updated the format to a regular VIP format
• The in-game browser and in-game radio buttons
• The "Learn Skill" tab in the player skills window

Removals are scripted by path, so they survive a client patch and are trivially reversible if a buyer wants any of them back.

 

Reworked the UI toward an actual Lineage II feel

 

The original LU4 UI looks AI-generated. It doesn't feel like Lineage II. A good part of it has been reworked toward the classic look — the menu button row rebuilt as a wrapping layout with a proper background, the self status and target windows cleaned up, and 590 asset field edits covering textures, positions, colours, text and compiled Blueprint literals.

 

This part is not finished, and I want to be straight about that But the tooling to continue it is all there, and it's the good kind of tooling: you can target any widget property in any UI asset by dotted path, remove widgets by path without knowing their auto-generated slot names, and edit text that's dynamically bound through Blueprint bytecode rather than stored as a plain property. Continuing the UI work means adding lines to a data file, not reverse engineering anything new.

 

Other client-side work

 

• A custom login scene, built in a real Unreal Engine project that's included
• Interlude music restored, plus ambient sound work (cities only for now)
• Custom splash and branding

 

What's included

 

All six git repositories, the Unreal Engine project and its custom assets, all the tooling — injector, hook, sniffer, decryptor, asset editor — every data set including geodata, XML, HTML and the SQL schema, the build and repack scripts, and the per-repo technical documentation including the reverse-engineering notes.

 

Happy to answer questions or show it running.

 

Gallery

 

A video to show the project is legit:

 

 

 

10k USD debatable

Edited 3 hours ago by kroma-l2
video

[Huggo]

I suggest you provide Test server for public and add a price.

[kroma-l2]

3 hours ago, Huggo said:

I suggest you provide Test server for public and add a price.

 

Unfortunately, it would require a lot of work. I added a video in the post. Feel free to ask me to capture anything you want.

[Huggo]

 Youtube and MXC acc created today, no test server, no price tag, looking like LU4 community Test server, if honestly looks fishy asf to me xD

[kroma-l2]

10 minutes ago, Huggo said:

 Youtube and MXC acc created today, no test server, no price tag, looking like LU4 community Test server, if honestly looks fishy asf to me xD

 

Ask me for proofs, and I will provide them on video

Edited 3 hours ago by kroma-l2

[Setekh]

You know how you can point out at a AI "project" with out the blatant AI text(like generic unimportant injection of features as Party matching, Offline shops or Mailbox & "substantial table rewrites") in this kinda posts?

They come out out of no where, suddenly, they sell you a solution you can do yourself if you have a 5x or 20x AI sub.

 

Selling the work of other and just saying "i rewrote AB data from one part of the other", gr8 bro! Anyone today can do it.


On another note, first time seeing Lu4, gourgious! Tho some of the lighting is fucked in this client, it looks way better than standard l2, but what's with this unshaded shit. SSAO or some cheap GI too costly? lol

Edit: In the Aden church, I saw some SS reflections and AO... but bad

Edited 2 hours ago by Setekh

[kroma-l2]

9 minutes ago, Setekh said:

You know how you can point out at a AI "project" with out the blatant AI text(like generic unimportant injection of features as Party matching, Offline shops or Mailbox & "substantial table rewrites") in this kinda posts?

They come out out of no where, suddenly, they sell you a solution you can do yourself if you have a 5x or 20x AI sub.

 

Selling the work of other and just saying "i rewrote AB data from one part of the other", gr8 bro! Anyone today can do it.


On another note, first time seeing Lu4, gourgious! Tho some of the lighting is fucked in this client, it looks way better than standard l2, but what's with this unshaded shit. SSAO or some cheap GI too costly? lol

 

Testing every packet by hand was painful, I don't think an AI will launch L2, edit one packet byte, do one actions, see the result in game. Rinse and repeat. And yes, I used AI to embellish my message as my English level sucks.

Edited 2 hours ago by kroma-l2
bad english

[Setekh]

What do you mean, that's 1o1 live smoke testing with AI, it even suggest it itself. If you had to do it in the big 2026 by hand, thats a skill issue bro lol

[Trance]

20 minutes ago, kroma-l2 said:

 

Testing every packet by hand was painful, I don't think an AI will launch L2, edit one packet byte, do one actions, see the result in game. Rinse and repeat. And yes, I used AI to embellish my message as my English level sucks.

It can, if you set it up cleverly. But that’s not the point.
You’re selling something half-baked that was made with AI in most cases.
"This is a few months of work"

[kroma-l2]

33 minutes ago, Trance said:

It can, if you set it up cleverly. But that’s not the point.
You’re selling something half-baked that was made with AI in most cases.
"This is a few months of work"

 

What is half baked? And what do you mean by made with AI in most cases? What do you know?

 

It was about 2 months of work on their newer client, and one extra was wasted on their first unreal engine 4 client since they completely changed the game protocol plus none of the original injected dll was usable on the newer client.

 

I edited their UI by hand (over 1k individual changes that needs PAK file rebuild + game restart).

 

If you guys can make it in a few days with the help of AI, that's great, I did not. 

 

[Setekh]

sure buddy

[Huggo]

How I said not even test server and selling something,  acc in mxc created in youtube same day,  no price tag, a bit how scamers works in other words saying .

[rexen]

Even if are work there, you use a client made for other project on U4 (now are U5 btw) to make packets communication with server and ask for 10k over price as fuck
And no test server why? if server side is based on acis mean is java you can rent a VPS for 5usd with linux and run on it