> ## Documentation Index
> Fetch the complete documentation index at: https://lastwar.tech/llms.txt
> Use this file to discover all available pages before exploring further.

# Extraction methodology

> How three custom, undocumented file formats were reverse-engineered from first principles to recover readable Lua and C# source from the APK.

Three custom, undocumented formats stood between "an `.xapk` file" and readable source. All three were cracked from first principles, without any prior tooling built for this game.

### 1: HybridCLR assembly de-obfuscation

The 117 hot-update C# assemblies ship as `assets/Assemblies/*.mdl`, renamed, single-byte-XOR-obfuscated `.dll` files. The header is deliberately corrupted just enough to defeat naive static scanners:

```python theme={null}
key = raw_bytes[3]          # the XOR key is stored in the file itself
n   = key                    # and doubles as the run length
for i in range(n):
    raw_bytes[i] ^= key       # XOR only the first `key` bytes, the rest is untouched
```

All 117 files decoded cleanly to valid PE/.NET assemblies on the first pass; 9 of the most relevant (`Assembly-CSharp.dll`, `SmartFox2X.dll`, `BestHttp.dll`, and friends) were decompiled to C# with [ILSpy](https://github.com/icsharpcode/ILSpy).

### 2: The `LWLF` Lua bundle container

The 105 MB `assets/lwScripts/LWScripts.data` is a custom archive bundling all 18,514 compiled Lua modules. Format, reverse-engineered by scanning for Lua's bytecode signature and reading backward:

```text theme={null}
LWLF magic (4B) | fileVersion (u32) | version (u32) | entry_count (u32)
per entry:
  name       .NET BinaryReader 7-bit-length-prefixed string
  byte_len   u32
  data       byte_len raw bytes (Lua 5.3 bytecode, itself self-delimiting)
```

(Later corroborated exactly against the C# reader, `LWLuaFile._Load`, see [Lua architecture](/lua-architecture).)

### 3: A deliberately non-standard Lua 5.3 bytecode header

Every compiled chunk sets the Lua chunk header's `format` byte to `1` instead of the standard `0`, and, the actual obfuscation, **omits the 1-byte "instruction size" field** that stock Lua 5.3 headers always include. Every other header field (int/size\_t/integer/float sizes, the `LUAC_INT`/`LUAC_NUM` sanity values) is stock. This is enough to make every off-the-shelf Lua decompiler reject the file outright.

<Info>
  **Fix**: A two-line patch to [unluac](https://github.com/HansWessels/unluac)'s `LHeaderType.java`, accept `format == 1`, and skip the instruction-size read when it's set, was enough to decompile all 18,514 chunks with a stock unluac release otherwise unmodified. Instruction encoding itself is completely standard Lua 5.1+, so nothing past the header needed touching.
</Info>

Once patched, this recovered readable Lua source for all 2,855 `Net/`+`Common/` modules (all 2,777 network command classes, the dispatch core, and the protobuf schemas) and all 1,279 game-data tables, the entire raw material for everything documented below.

### 4: Game data tables

`assets/table/table_*.data` is, despite the odd filename, a plain ZIP archive (magic `PK\x03\x04`), 1,279 entries, each itself Lua 5.3 bytecode encoding a data-only module (building costs, hero stats, activity config, etc). No new format needed; unluac with the same header patch handled these too.

| Artifact                          | Raw size         | Decoded to                                               |
| --------------------------------- | ---------------- | -------------------------------------------------------- |
| `assets/Assemblies/*.mdl` ×117    | \~42.7 MB        | Valid .NET assemblies, 9 decompiled to C#                |
| `assets/lwScripts/LWScripts.data` | 105 MB           | 18,514 raw `.luac` chunks; 2,855 decompiled (Net/Common) |
| `assets/table/table_*.data`       | 18.6 MB          | 1,279 decompiled Lua data tables                         |
| base APK Java/Kotlin (dex)        | \~42.3 MB        | 16,867 files via jadx                                    |
| native libs, `lib/arm64-v8a/`     | 7 relevant of 23 | Symbol/string survey only, no disassembly                |