OpenSpiel Installation on Windows

OpenSpiel now has official support for Windows with pre-built binary wheels available on PyPI. Windows wheels are built and tested automatically via GitHub Actions CI for Python 3.11, 3.12, and 3.13.

This section assumes that you are into the isolated virtual environment. To create one: PowerShell python -m venv .venv; .venv\Scripts\activate If you need, activate the permissions: PowerShell Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope CurrentUser

[!WARNING] Current API mostly functions under the assumption of a direct pip installation (Option 1). Contributing guidelines ../CONTRIBUTING.md currently work with unix-based commits due the endings difference. If you plan to contribute to the library, for now, strongly consider using a Unix- or Linux-based environment. See, for example, WSL2 environment Option 3.

Note: Windows support is currently experimental. If you encounter any issues, please open an issue on GitHub so we can improve the Windows experience.

Option 1: Quick Installation using pip (Recommended)

The easiest way to install OpenSpiel on Windows is using pip:

pip install open-spiel

Optional dependencies

For additional features like visualization and machine learning: Bash pip install open-spiel[full]

Verification

Test your installation: python -c "import pyspiel"

Create a simple game

Directly in CLI:

python -c 'import pyspiel; game = pyspiel.load_game("tic_tac_toe"); state = game.new_initial_state(); print("OpenSpiel is working!")'

or in an editor:

import pyspiel
game = pyspiel.load_game("tic_tac_toe")
state = game.new_initial_state()
print("OpenSpiel is working!")

Output all the available games

python -c 'import pyspiel; print(pyspiel.registered_names())'

Building from Source

If you need to build from source or contribute to the project:

Prerequisites

• Python 3.11+ (get from python.org)

• Git (get from git-scm.com)

• CMake 3.15+ (get from cmake.org)

• Visual Studio 2019 or later with C++ development tools from Microsoft

[!NOTE] Don’t foget to add installed programmes to PATH checking the option when committing the installation.

Build Steps

1. Clone the repository: bash git clone https://github.com/deepmind/open_spiel.git cd open_spiel

2. Build the wheel: bash python -m pip wheel . --no-deps -w dist

3. Install the built wheel: bash pip install dist/open_spiel-*.whl

Troubleshooting

“CMake not found” - Install CMake from cmake.org and add it to your PATH

“Git not found” - Install Git from git-scm.com and add it to your PATH

“MSVC compiler not found” - Install Visual Studio Community with C++ development tools - Or install “Microsoft C++ Build Tools”

“Import pyspiel failed” - Make sure you installed the package: pip install open-spiel. - Try finding it in the list of installed packages: pip show open-spiel. - In case of any errors try reinstalling: pip uninstall open-spiel && pip install open-spiel

Development Installation (Python API)

Clone the repository

git clone https://github.com/deepmind/open_spiel.git
cd open_spiel

Clone necessary submodules:

For the full process, you can refer to the installation script (../open_spiel/scripts/install.sh).

git clone --single-branch --depth 1 https://github.com/pybind/pybind11.git pybind11
git clone -b 20250814.1 --single-branch --depth 1 https://github.com/abseil/abseil-cpp.git open_spiel/abseil-cpp
git clone -b master https://github.com/nlohmann/json.git open_spiel/json
cd open_spiel/json && git checkout 9cca280a4d0ccf0c08f47a99aa71d1b0e52f8d03 && cd ../..
git clone -b master https://github.com/pybind/pybind11_json.git open_spiel/pybind11_json
cd open_spiel/pybind11_json && git checkout d0bf434be9d287d73a963ff28745542daf02c08f && cd ../..
git clone -b master https://github.com/pybind/pybind11_abseil.git open_spiel/pybind11_abseil
cd open_spiel/pybind11_abseil && git checkout 73992b5 && cd ../..
git clone -b develop --single-branch --depth 1 https://github.com/jblespiau/dds.git open_spiel/games/bridge/double_dummy_solver

[!NOTE] CLI separators “&” and “|” appear not in every version (for example, in PowerShell, they are active since Version 7.xx.xx). If the code does not work, replace “&&” with “;”.

It may take substantial amount of time.

pip install -e .

If during the installation you get fatal error C1083: Cannot open include file: 'graphviz/cgraph.h': No such file or directory, it is recommended to separately download Graphviz and reinstall with the following command (or use Chocolatey): Bash python -m pip install --config-settings="--global-option=build_ext" ` --config-settings="--global-option=-IC:\Program Files\Graphviz\include" ` --config-settings="--global-option=-LC:\Program Files\Graphviz\lib" ` pygraphviz

Using with Conda

conda create -n openspiel python=3.11
conda activate openspiel
pip install open-spiel

Option 2: Windows Installation using Visual Studio Community Edition (Full installation)

This option will describe how to install and use OpenSpiel on Windows 11 via Visual Studio Community Edition. This process has been written for Windows 11 and tested on Windows 11 Version 25H2, build 26200.8037 (April 2026).

When installing Visual Studio, enable the C++ and Python development, and also the C++ CMake tools for Windows. C++/CLI support and C++ Clang tools may also be useful (but not necessary).

You will need to have the following dependencies installed:

• CMake

• git

• Python >= 3.11. Tick the box during installation to ensure Python executable is in your path.

• Recommended: Windows Terminal / Powershell.

The rest of the instructions will assume that OpenSpiel is cloned in C:\Users\MyUser\open_spiel.

Open a Windows Terminal (Windows Powershell), clone OpenSpiel and its dependencies (commands adapted from the installation script (../open_spiel/scripts/install.sh)

cd C:\Users\MyUser
git clone https://github.com/deepmind/open_spiel.git
cd open_spiel
git clone --single-branch --depth 1 https://github.com/pybind/pybind11.git pybind11
git clone --single-branch --depth 1 https://github.com/pybind/pybind11_json.git open_spiel\pybind11_json
git clone --single-branch --depth 1 https://github.com/abseil/abseil-cpp.git open_spiel\abseil-cpp
git clone --single-branch --depth 1 https://github.com/nlohmann/json.git open_spiel\json
git clone https://github.com/pybind/pybind11_abseil.git open_spiel\pybind11_abseil
git clone -b develop --single-branch --depth 1 https://github.com/jblespiau/dds.git open_spiel\games\bridge\double_dummy_solver

Open Visual Studio and continue without code. Then, click on File | Open -> CMake, and choose C:\Users\MyUser\open_spiel\open_spiel\CMakeLists.txt. CMake will then run; once you see CMake generation finished, choose Build -> Build All. The files will be available in C:\Users\MyUser\open_spiel\open_spiel\out\build\x64-Debug, when the build completes with “Build All succeeded.” Extra compilation options may be necessary if errors occur.
MSVC options to deal with required C++ standard, file encoding (for chess characters) and large object files include /std:c++20, /utf-8, /bigobj. To use them together with default MSVC arguments, you can use the following CMake command line arguments: -DCMAKE_CXX_FLAGS="/std:c++20 /utf-8 /bigobj /DWIN32 /D_WINDOWS /GR /EHsc"

To be able to import the Python code (both the C++ binding pyspiel and the rest) from any location, you will need to add to your PYTHONPATH the root directory and the open_spiel directory. Open Windows environment variables and add to the PYTHONPATH. Add the directories C:\Users\MyUser\open_spiel\open_spiel\out\build\x64-Debug and C:\Users\MyUser\open_spiel\open_spiel\out\build\x64-Debug\python to PYTHONPATH. If your PYTHONPATH does not exist, then create a new environment variable for it. To check that python is working, you can run the example in open_spiel\python\examples.

OpenSpiel has various Python dependencies which may require installing. At a minimum, you will need the ones in pyproject.toml.

pip install absl-py
pip install attrs
pip install numpy

For a complete list, depending on what you will use, see optinal dependencies of the ../pyproject.toml. To set a env variable in the current terminal you can use the command set(some help)

Option 3: Windows Installation using Windows Subsystem for Linux (WSL2)

This section describes the installation steps to get OpenSpiel running in a Windows 10/11 environment using WSL2.

Process

1. Install WSL2 with Ubuntu:

   Run the following command in an elevated Windows Powershell:

   wsl --install
   

   This installs WSL2 with Ubuntu by default. Restart your machine if prompted.

2. First time run of Ubuntu:

   Open Ubuntu from the Start Menu. Provide a username and password for the default user account.

3. Once the Ubuntu environment is running, follow the standard Linux installation instructions in install.md to clone, build, and set up OpenSpiel.