In the first person
You see through your robot's eyes: look around the hall, lean over the board, look up at your opponent, glance at your scoresheet, or stand and walk to an end of the table.
Version 1.0.0
Scacelith
The Royal Game
Take your seat at a waxed walnut table in a sunlit royal hall. Across the board, a porcelain robot driven by Stockfish waits for your first move.
Captured in the game: the royal hall
- In-house OpenGL 4.6 engine
- Stockfish 19 built in
- FIDE rules
- Online play
- 34 languages
IThe experience
Not a board on a screen.
A seat at the table.
Scacelith brings back what makes a real game: the hall, the silence, the clock, an opponent who looks at you, and the rituals of the tournament.
Tournament rules
A piece you touch must be moved, and your hand presses the clock to complete the move. With the move hints off, the arbiter penalises an illegal move, and a second one loses the game.
Written by hand
Both players record every move on their own scoresheet, each in a handwriting of their own, and turn the page every forty moves. You hear the pen on the paper.
A worthy opponent
Stockfish 19 at your level, from Novice (800) to Stockfish Max (3500), with a rating computed by the FIDE rules after every game.
Built for this game
An engine written from scratch: physically based light, marble, waxed wood, porcelain and brass, the sun through the windows, soft shadows and reflections. Quality presets, from Very low to Ultra, fit it to your graphics card.
34 languages
English, French, German, Spanish, Portuguese from Portugal and Brazil, Italian, Dutch, Swedish, Danish, Finnish, Estonian, Latvian, Lithuanian, Polish, Czech, Slovak, Slovenian, Croatian, Hungarian, Romanian, Bulgarian, Greek, Turkish, Ukrainian, Russian, Arabic, Hindi, Indonesian, Vietnamese, Korean, Japanese and Chinese, simplified and traditional. Arabic is laid out right to left, and the coach speaks aloud in every language except Chinese, where its words appear as subtitles.
IIWays to play
Every game
has its table.
Everything is played in the same hall, from the title screen. Offline, Stockfish is always ready for a game.
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New Game
Face Stockfish at the strength of your choice, with a time control from bullet to classical, or play a friend on the same computer, each from their own robot's eyes.
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Coach
A teacher sits across from you, plays at your level and talks you through the game: threats, good moves, mistakes, playing out with its own hand what a mistake costs. From the rules of chess to expert level, with a voice synthesised on your computer.
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Coach Challenges
Short sets of positions, each training one skill: mates in one to three, forks, pins and other tactics, defence, and the basic endgames against the coach. Hints only when you ask, and a green check for every set you complete.
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Analysis
Stockfish reviews your saved games, your online games or any PGN: an evaluation bar, the key moves marked from brilliant to blunder, the better move drawn as an arrow, and comments aloud and in subtitles. The robots' hands play the moves as you step through.
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Play Online
Real opponents through a Scacelith server: rated games, matchmaking, challenges and private games, or a direct match between two computers. Your opponent's robot moves with them, live.
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Watch a Game
Two Stockfish players face each other while you move freely around the hall, invisible, from one viewpoint to another.
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Saved Games
Your games are kept as PGN files. Replay them in the hall, with the real thinking times and clocks, or bring in games from other programs.
IIIGallery
Seen from inside the hall
Every picture is captured in the game, in real time, by its own engine.
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The title screen
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Coach
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Coach Challenges
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Analysis
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Watch a Game
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Your opponent
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The royal hall
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The scoresheet
Version 1.0.0. The interface in these pictures is in English.
IVTrailer
Scacelith in motion
Nothing is loaded from YouTube until you accept its player. Watch on YouTube
VOnline
Real opponents,
the same hall.
Sign in to the official server from the game and play people from everywhere, still in the first person.
- Rated games in every official time control, each with its own rating, computed by FIDE's rules.
- Matchmaking, challenges by name and private games with a code; or a direct match between two computers, with no server or account.
- Fair play: automatic checks, engine analysis of finished games and player reports.
- Your game history on this site: download each game as PGN or as an animated GIF.
- Anyone can run a community server: the server is free software, and its API is documented.
VIDownload
Take your seat.
Free, and open source.
Unpack and play: no installer on Windows or Linux, and a drag to Applications on a Mac. Every file is built from its tagged source by GitHub Actions, with an attested build provenance.
Scacelith
- System
- Windows 64-bit (x64); Linux 64-bit (x86-64 or aarch64) with glibc 2.34, OpenSSL 3 and X11 or XWayland, such as Ubuntu 22.04 or Debian 12; macOS 26 or later on Apple Silicon (experimental)
- Graphics
- A graphics card with OpenGL 4.6 and an up-to-date driver (on a Mac, the game brings its own OpenGL)
- Included
- Stockfish 19 and its neural network: play offline right away
- Internet
- For online play, GIFs, and the voice of the coach and of the analysis (an optional download of about 399 MB)
- Licence
- GNU General Public License v3
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Windows
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macOS
ExperimentalFor Apple Silicon Macs (M1 or later) with macOS 26 or later, not in a virtual machine; newer and less tested than the other builds. The app is not signed by a registered Apple developer: the first time, open it from System Settings › Privacy & Security › Open Anyway.
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Linux
Check your download
Each file's build provenance is attested by GitHub. With the GitHub CLI:
gh attestation verify Scacelith-…-windows-x64.zip --repo DarkCenobyte/scacelith-chess
VIICredits
Credits and thanks
- Chess engine
- Stockfish 19, by the Stockfish developers (GNU GPL v3). Its neural network was trained on data provided by the Leela Chess Zero project (Open Database License).
- Voice
- Supertonic 3 by Supertone, under the BigScience Open RAIL-M licence: downloaded at your request, it speaks for the coach and the analysis, on your computer.
- Typefaces
- EB Garamond by Georg Duffner, Cinzel by Natanael Gama and Amiri by Khaled Hosny; handwriting in Caveat, Marck Script, Bad Script, Aref Ruqaa, Klee One and LXGW WenKai (all SIL Open Font License); chess figures from GNU FreeFont.
- Openings and puzzles
- Opening names from the chess-openings database of lichess.org, and the puzzles of the coach's challenges from the Lichess puzzle database, both dedicated to the public domain (CC0).
“Chess is the art of analysis.”