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Engine Open source v0.7.1

Moddable Chess

74 playable variants. Five AI difficulties. Three consumer apps. The most modded game in history finally gets an open-source home.

chess.moddable.gamesGitHub
Variants 74
AI Difficulties 5
Consumers 3
Engine v0.7.1
Board types Square · 4×8 to 12×8
Status Live
SUPPORTED VARIANTS

74 variants. Six categories. One engine

01

Standard + Classics

Regular chess plus Fischer Random, No Castling, and Torpedo — familiar rules with one twist each.

02

Alternate Win Conditions

King of the Hill, Three-Check, Racing Kings, Extinction — different paths to victory.

03

Chaos Variants

Atomic, Duck Chess, Fog of War, Horde, Rifle — explosive mechanics that shatter standard strategy.

04

Big Boards

Capablanca (10×8), Grand (10×10), Courier (12×8) — wider boards with fairy pieces. Plus Breakthrough on 7×7.

05

Asymmetric

Maharaja & Sepoys, Antichess, Marseillais — unequal forces or unequal turns. Mind-bending.

06

Dungeon Chess

Our most ambitious variant — four asymmetric factions, XP drafting, cannon mechanics, and modular dungeon boards. A total conversion of chess.

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THE ONLINE ENGINE

Play anywhere.
Continue everywhere

Create private sessions. Hand off mid-game between phone, tablet, and laptop. Pause a session in May, finish it in October. The board waits.

Embed APIConsumer APIsAI + Opening booksGame controllerDeveloper guidesTouch/mobile
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EMBED API

Embed in your own project

One iframe. Full game board. Theme-aware, responsive, touch-ready.

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Embed via iframe
Drop a single iframe into any page. Control variant, theme, difficulty, and layout via URL params. Responsive and touch-ready.
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postMessage control
Switch variants, change themes, and reset games without reloading the iframe. Send typed messages to the embed window.

Built on this engine

Dungeon Chess

Asymmetric fantasy strategy on modular dungeon boards. Four factions, 24 units, XP drafting.

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Chess Variant Loader

Pick, preview, and play any of 74 variants from the browser. Rules reference and match launcher.

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