D2MOO - Diablo II Method and Ordinal Overhaul

This project is a re-implementation of the Diablo2 game coupled with patching facilities for modders. The aim is to provide the modding community with an easy tool to understand and patch the game. To ensure that we stay as close as possible to the original game, we do not provide fixes for bugs (yet).

The game assets, main executable code and anything related to hacking or piracy is NOT endorsed by the authors, and as such we will not provide code related to such subjects. The original game assets and binaries is required to use this project.

How to build

Dependencies

For the patching we rely on the D2.Detours project, which is included as a git submodule. (use the git submodule update --init command, or clone this project with git clone --recursive) You will also need to install the CMake build system and Visual C++ (or any C++ compiler that can generate .DLLs on Windows) which are freely available.

Build the project

The preferred way is to use CMake presets. You can either open D2Moo using the Visual studio "Open folder" or generate a VS solution (in out/build/VS20XX) using:

# Configure the CMake project
cmake --preset VS2019
# Build the release config
cmake --build --preset VS2019 --config Release
# Install
cmake --build --preset VS2019 --config Release --target install

Note: The ninja preset requires to run the cmake configuration step to be ran from the x86 Native Command Prompt.

Or, if you do not wish to use the presets

# Configure the CMake project
cmake -A Win32 -B YOU_BUILD_DIR
# Build the release config
cmake --build YOU_BUILD_DIR --config Release
# Install
cmake --install YOU_BUILD_DIR --config Release --prefix YOUR_INSTALL_FOLDER

Usage

• Build D2MOO
• Launch Diablo2 (or D2SE) by using the command D2.DetoursLauncher [Path to D2 or D2SE].
  • If the Game.exe/D2SE.exe executable is not provided, you can start it from the game folder. It can also detect the installation path.
  • The detours .dll expects patch dlls to be in patch folder of the Diablo2/D2SE executable. This can be overriden using the DIABLO2_PATCH environment variable.

The debug targets are already configured and set as startup project when using Visual Studio.

Note that it will spawn the game/D2SE as a subprocess, so you might be interested in the following Visual Studio extension Microsoft Child Process Debugging Power Tool. Then go to Debug > Other debug targets > Child process debugging settings, enable & save.

Versions

The project is currently based on the 1.10f version of the game. Feel free to submit patches for other versions of the game!

FAQ

Why is the code so ugly and with names such as a1, a2, ... ?

The code was originally extracted using a reverse engineering tool, and slowly cleaned to use more understandable names.

Can I build D2Common.dll and replace it directly with the one from the game ?

Not yet, but this is one of the objectives ! We are in the (slow) process of checking each ordinal (exported functions) and patching them one by one. See D2Common.patch.cpp for the current status of each ordinal.

Why are some DLLs missing ?

Reversing the game is very time consuming. Since D2Common.dll and D2Game.dll contain most of the game logic, this is where the focus has been set. Any contribution and help is welcome !

How can I write my own mod using this ?

The documentation for that is not written yet, please contact us directly on the Phrozen Keep forums / Discord server. More importantly, we need your feedback to determine a roadmap.

Why yet another project for D2 modding and code editing ?

We felt that the current projects are not good enough, and more importantly did not cover enough parts of the game. Having a centralized code that one can launch and use as reference will make it easier, we hope, for the modding community.

I can not set breakpoints in Visual Studio

Please have a look at Microsoft Child Process Debugging Power Tool.

I have other questions !

Please feel free to open an issue or visit the Phrozen Keep forums / Discord server !

Credits

This could not have been done without the amazing help and work of the Phrozen Keep community! Non-exhaustive list of members who helped putting this together (alphabetical order):

• @Conqueror
• @dzik
• @FearedBliss
• @Firehawk
• @Harvest
• @Kieran
• @Kingpin
• @Lectem
• @lolet
• @Mentor
• @MirDrualga (aka @IAmTrial)
• @misiek1294
• @Mnw1995
• @Myhrginoc
• @Necrolis
• @Nefarius
• @Nizari
• @Ogodei
• Paul Siramy
• @raler (that sparked the idea for the current name of the project)
• @SVR
• @Szumigajowy
• @whist
• ...

If you think you should be on this list, reach us on the forum, discord, or open a pull request!

Legal

The source code in this repository is intended for non-commercial use only. However it uses a permissive license so that any modder may use this. Credits to the team are appreciated, and the license must be preserved in derivative work.

Battle.net(R) - Copyright (C) 1996 Blizzard Entertainment, Inc. All rights reserved. Battle.net and Blizzard Entertainment are trademarks or registered trademarks of Blizzard Entertainment, Inc. in the U.S. and/or other countries.

Diablo(R) - Copyright (C) 1996 Blizzard Entertainment, Inc. All rights reserved. Diablo and Blizzard Entertainment are trademarks or registered trademarks of Blizzard Entertainment, Inc. in the U.S. and/or other countries.

D2MOO and any of its' maintainers are in no way associated with or endorsed by Blizzard Entertainment(R).