Caïssa Board

Caïssa Board – A Modern Chess GUI

The Evolution of a Modern Chess GUI

Graphical user interfaces (GUIs) for chess first appeared in the 1990s. While chess engines became vastly stronger over the decades, the GUIs themselves remained largely unchanged.

Caïssa Board was created to rethink how a chess interface presents information:

• 1. Visual Tactics First: It started with a core idea: make tactics visible. Instead of forcing players to read raw engine numbers, Caïssa Board outlines forks, pins, and hanging pieces directly on the board.

• 2. Variants & Lichess: Expanded to support 13+ chess variants in both 2D and 3D, along with native Lichess integration for playing online.

• 3. Database Engine: A dedicated database system was added, enabling fast 20-move position searches and custom Lua scripting.

• 4. Modding System: A built-in Mod Manager and GitHub toolkit were introduced to help players create custom piece sets, boards, and maps.

• 5. The 3D Online Club: Online matchmaking was redesigned into Chess Island, a 3D world where players walk up to physical chessboards as 3D characters.

• 6. LLM & Accessibility: Finally, experimental AI analysis was integrated to evaluate the moves, alongside Text-to-Speech (TTS) accessibility for blind and low-vision players.

Analysis & Study Tools

• Tactical Outlining: Visually highlights tactical motifs, forks, pins, threats, and hanging pieces directly on the board squares.

• LLM Analysis Mode: Uses large language models to evaluate a position based on chess engine evaluation.

• Engine Support: UCI and CECP support to run engines like Stockfish and Fairy Stockfish

• Lua Database Querying: Search large PGN databases using built-in filters or custom Lua scripts. Supports SQLite and PostgreSQL. Includes a built-in database of 2 million games.

• Lichess Integration: Play online (rated, casual or vs computer).

The Online Chess Club: Chess Island

• 3D Third-Person Exploration: Control a 3D character directly, walking around a sunny, Greece-themed outdoor island environment.

• Interactive Outdoor Chessboards: Walk up to giant chess sets placed in the environment, press to interact, and open the board interface to start playing.

• King-of-the-Hill Blitz: A continuous rotation board where the winner stays seated and the next challenger in line steps up automatically.

• Casual Chessboards: Walk up to open casual chessboards, and set up quick matches.

13+ Variants (2D & 3D Views)

Play standard games or explore traditional and modern variants:

• Chess Variants: Standard, Chess960, Antichess, Atomic, Crazyhouse, Horde, Infiltration, King of the Hill, Racing Kings, Three-Check

• Regional Classics: Xiangqi (Chinese Chess), Shogi (Japanese Chess)

• Expanded Board: Capablanca Chess (10×8)

Modding & Accessibility

• Screen Reader & Speech: Includes full Text-to-Speech (TTS) integration that speaks move names, game status, and UI elements aloud.

• Built-in Mod Manager: Create custom chess sets, 3D maps, and scripts from within the application and an Unreal Engine project available on github.

• Mod Kit: Create custom PAK files using the open-source GitHub toolkit.

Demo Restrictions:

• 250 games maximum per collection

• Multiplayer limited to official server

• Basic outfits for characters