wowdecomp

A C++ decompilation of the World of Warcraft 3.3.5a client (Wow.exe, build 12340, June 2010).

Join the discord for other clients and to show off some cool stuff you build.

https://discord.gg/DsZMGUD8aT

Every function is reconstructed from the original binary and keeps the address it came from in an // OFFSET: tag, so each one can be compared against the original. The source tree follows the layout of the original client (Engine/Source/<Module>, WoW/Source/<Module>, original file names).

x64 is the main target. Win32 still builds and is used to check struct layouts against the 32-bit original.

Progress

The percentages below measure how much of the original binary has a counterpart in this source tree. They do not say how much of the game works, and the missing part is not missing gameplay: the client builds into a complete executable and the game is 100% playable. Bugs could still be hiding, though; a ported function can behave differently from the original.

Measured against the 12340 binary on 2026-10-15. A function counts as ported when its address is tagged in the source.

	Ported	Total	Share of the original
Functions	24,515	27,157	90.3%
Code bytes	5,270,186	5,656,573	93.2%

The total leaves out 658 functions that IDA identifies as compiler library code and 132 import thunks. Most of the untagged remainder is code the build gets elsewhere: compiler-generated code (static initializers, template instances) that our compiler emits on its own, C runtime helpers, and third-party libraries that are linked from their upstream sources instead of being decompiled (FreeType, zlib, PCRE, parts of FMOD Ex).

Requirements

• Windows 10 or 11
• Visual Studio 2022 with the Desktop development with C++ workload (MSVC v143 and a Windows SDK)
• CMake 3.10 or newer (the one that ships with Visual Studio works)
• For Win32 builds only: NASM, on PATH or passed as -DNASM_EXECUTABLE=<path>, and DivxDecoder.dll from your 3.3.5a client copied to ThirdParty/DivxDecoder/ (the build copies it next to the executables; the x64 build uses its own decoder instead)
• A World of Warcraft 3.3.5a (12340) client. No game data is included in this repository.

Building

From a Developer PowerShell or any shell with cmake on PATH:

git clone https://github.com/SatyPardus/wowdecomp.git
cd wowdecomp

# x64 (main target)
cmake -S . -B build/x64 -G "Visual Studio 17 2022" -A x64
cmake --build build/x64 --config Release --target WowClient --parallel

# Win32 (optional, needs NASM)
cmake -S . -B build/win32 -G "Visual Studio 17 2022" -A Win32
cmake --build build/win32 --config Release --target WowClient --parallel

In-source builds are refused, so keep the build directory separate (build/ above).

The client is written to bin/Win/:

Target	x64	Win32
WowClient	WowClient64.exe	WowClient32.exe
Wow	Wow64.exe	Wow32.exe

WowClient is the client with a crash logger: it opens a console window and writes WowClient_crash.log when the client crashes. Wow is the same client without it. You can also turn the logger off in WowClient with -DWOWCLIENT_CRASH_LOG=OFF.

Options

CMake option	Default	Effect
WOWDECOMP_DISABLE_SIGNATURE_CHECKS	OFF	Skip the MPQ file and .toc.sig signature checks, so modified game data and interface files load
WOWCLIENT_CRASH_LOG	ON	Build WowClient with the crash logger
WOWCLIENT_OUTPUT_OVERRIDE	empty	Name the WowClient executable something other than WowClient64 / WowClient32

Running

1. Copy the Data folder of your 3.3.5a client into bin/Win/, so you have bin/Win/Data/.
2. Point Data/<locale>/realmlist.wtf at the server you want to connect to.
3. Start bin/Win/WowClient64.exe (or Wow64.exe).

Layout

Path	Contents
Engine/Source/	Engine modules: Storm, Gx (Direct3D 9 / OpenGL), Model2, Frame/FrameXML UI, SoundEngine, Lua, ...
WoW/Source/	Game modules: objects, world rendering, UI, networking, database, glue screens
WoW/Common/	Code shared by the game modules
ThirdParty/	Libraries linked from their upstream sources
Tools/WowClient/	The WowClient executable target
Tools/XvidDecoder/	x64 movie decoder that replaces the original 32-bit DivxDecoder.dll

Special thanks

• binana
• thunderbrew
• whoa
• TOMRUS, for the initial IDB
• Everyone who has reported bugs so far
• The WoW modding community