NBG CHESS VARIANT

Novixx Board Game (Chess) is a chess variant like Drawback Chess, but open source. Add your own drawbacks in drawbacks.py and then modify the random.choice in game.py (will make it automatic later)

https://nbg.novixx.com:8080/

Certificate is untrusted (and thus the browser warning) (12/1/2025), will switch to cloudflare soon. You can obviously run it locally too.

You can't donate to Novixx Systems (yet) but you can support the project that we based NBG on, PyChess (see below)

ORIGINAL PYCHESS README: START

www.pychess.org

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Pychess-variants is a free, open-source chess server designed to play chess variants.

Currently supported games are listed on https://www.pychess.org/variants

For move generation, validation, analysis and engine play it uses:

• Fairy-Stockfish
• fairy-stockfish.wasm
• fairyfishnet fork of fishnet

On client side it is based on chessgroundx fork of chessground

As you know, pychess-variants is a free server and it will remain free forever. However, maintaining and improving the server costs time and money.

If you like our work and find our server useful, please donate through Patreon or directly through paypal !! Your contribution will be greatly appreciated and help me continue to develop this awesome server.

Installation

Prerequisites

• You need MongoDB up and running. Mongo daemon

Project setup

# Install python requirements with pip
pip install . --user
# Use pip with [dev] for local development with testing tools
pip install .[dev] --user

# Alternatively, use uv to install python requirements in a virtual env
uv sync
# Use uv with --extra dev for local development with testing tools
uv sync --extra dev

yarn install                            # Install node requirements
yarn dev                                # Compile typescript files to javascript
yarn md                                 # Compile md files to html

Start server

python3 server/server.py

Or if uv is used

uv run server/server.py

Docker setup

If you want to avoid installing dependencies (mongo, node, python) you can instead run the server locally in docker using compose. To start it, simply run:

docker compose up --build

This recompiles the frontend and starts the server and DB. Once it is up, you can connect to localhost:8080 in your browser.

Supported browsers

Pychess-variants should support almost all browsers. Though older browsers (including any version of Internet Explorer) will not work. For your own sake, please upgrade. Security and performance, think about it!

Only Fairy-Stockfish analysis might not work on all browsers.