Crab CanonGames of surfaces, connections and time
Crab Canon brings together chess, shogi and Go on a Möbius strip, a Klein bottle and a genus-two surface, plus CrystalGo and TimeGo. Play with another person on the same device, try a local practice opponent, or explore the interactive tutorials.
Created by N-Y-L and contributors. Version 0.5.0.
Your games stay on your device
Games and computer opponents run in your browser. There are no player accounts or paid model APIs. Browser saves belong to this browser and site address; export a JSON record to keep a backup or move to another device. Localhost saves do not automatically appear at crabcanon.games.
Activity and privacy
To understand which games people play, Crab Canon counts a play session after three human moves in play mode, and counts completed tutorial lessons. Computer moves, analysis, imported records and simply opening a page do not count. Sessions are separate for each game and variant in each tab, and restart after 30 minutes without tracked activity. These counts measure sessions, not individual people.
A count sends only the game, variant, event type, lesson identifier when applicable, and a random event receipt used to prevent duplicates. It does not send your moves, saved games, name, email or a persistent player identifier. Counts are stored with Cloudflare for the site's private owner dashboard. The hosting provider also processes ordinary network requests to deliver and protect the site.
Duplicate-prevention receipts are deleted in daily cleanup after seven days; daily aggregate totals are kept for 365 days. Tutorial counts distinguish exercises solved without demonstrated answers from CrystalGo walkthroughs explicitly marked finished. Collection is best effort: blocked requests and offline play may not be counted.
Use this setting on each browser or device you want excluded. It applies to future activity, including other open tabs on this site. Clearing site data or using another browser resets the setting. Previously recorded aggregate counts cannot be linked back to you and are not removed.
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Play, share and give credit
You are welcome to play here, share links, share your game records, and post screenshots of your play with credit to Crab Canon — N-Y-L and a link to crabcanon.games.
The current application has a restricted-use license. Copying, mirroring, redistributing or adapting protected material requires permission except where a separate license or applicable law permits it. Giving credit alone does not grant permission.
When discussing or building on the original game designs, please cite N-Y-L, Crab Canon: Games of Surfaces, Connections and Time, with the version and website address. Traditional games, abstract ideas, mathematical facts and game methods are not claimed as exclusive property.
Component credits
Source Sans 3 and Source Serif 4 are bundled under the SIL Open Font License. The local opponent package and its earlier Surface Games engine snapshot retain their MIT licenses. See all component notices. Existing permissions for earlier MIT releases remain in place.
The board-centered interface takes visual inspiration from Lishogi; no Lishogi code, branding or artwork is bundled.