About

AjaxChess.com is a free online chess platform built for players of all skill levels. Whether you're new to chess or a seasoned tournament player, the site offers classic puzzles alongside unusual variants like Kriegspiel, a hidden-information form of chess where you can't see your opponent's pieces.

The site is built and maintained by Richard Cross, founder of Regis Consulting, a software consultancy specializing in web development. AjaxChess.com is built from scratch using Python, FastAPI, and modern web technologies — no off-the-shelf engines, no borrowed game logic. Every game mode, every feature, and every line of code is original work.

What's on the Site

  • Kriegspiel: A multiplayer variant where each player sees only their own pieces and must deduce the opponent's position from move announcements. Supports three rule variants — Classic, Lovenheim, and Rochester — with optional clocks, bots, and spectators.
  • Knight's Tour: A classic mathematical puzzle where you must move a knight to every square on the board exactly once. Available in 5×5 through 8×8 board sizes, with a timed leaderboard.
  • Chess Puzzles: Tactical puzzles to sharpen your pattern recognition and calculation skills.
  • FICS Connection: Connect to the Free Internet Chess Server directly from your browser and play live games against humans worldwide.
  • Blog: Articles on chess history, variants, strategy, and the story behind the site.
  • Links: A curated list of chess resources and our sister site, Minesweeper.org.

Why Kriegspiel?

Kriegspiel ("war game" in German) was invented in the 19th century as a training exercise for Prussian military officers. The chess variant of the same name strips away the perfect information that defines standard chess, replacing it with fog of war. You can see your own pieces, but you don't know where your opponent's pieces are — you can only infer their positions from what the referee announces after each move attempt.

Playing Kriegspiel develops a different set of skills from standard chess: probability estimation, risk tolerance under uncertainty, and reading what your opponent's silence tells you about their position. It's one of the oldest and most intellectually interesting chess variants, and we think it deserves a modern, well-implemented home on the web.

About the Developer

AjaxChess.com is built and maintained by Richard Cross and the team at Regis Consulting. Richard has been building software since the late 1990s, working on everything from enterprise platforms to indie web projects. AjaxChess.com is a sibling project to Minesweeper.org, a free online minesweeper game with leaderboards, multiplayer duels, and no-guess puzzle generation.

Have questions, feedback, or a bug to report? Use the Contact page or email ajaxchess@gmail.com.

GitHub

Technical Details

  • Backend: Python and FastAPI
  • Frontend: Vanilla JavaScript with server-rendered HTML
  • Real-time: WebSockets for Kriegspiel multiplayer
  • Chess engine: python-chess for move validation and Stockfish integration
  • Hosting: AWS
  • Open source: The project is on GitHub.

The site is designed to be fast, lightweight, and accessible. It works on desktop and mobile browsers without requiring any downloads or plugins.

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