September 20, 2026
Games now come from a single prompt: Fable's UMBRA runs right in the browser
Ethan Mollick described a Fable game in one sentence and got UMBRA: a wordless game that opens in the browser via a link.
Ethan Mollick
@emollick
Worth trying without spoilers. I asked Fable: “I want you to make a visually beautiful game about moving away... let the camera pull back and reveal the unexpected.” I gave no other instructions, and the result is compelling and strange (though uneven). Play: https://play-umbra.netlify.app/
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You play as a shadow. It grows by absorbing other shadows: from a patch of darkness on a puppet screen to the Moon's shadow on the day of an eclipse.
The game is called UMBRA, and Fable created it from a single sentence. Mollick asked for a visually beautiful game about moving away, where the camera pulls back and reveals the unexpected, and clarified that he gave no other instructions (19.09.2026).
No installation needed. The play-umbra.netlify.app page launches the game immediately, with no registration required (checked 19.09.2026). It works on phones too, with touch controls included and no separate app.
Arcade games came earlier. At the Fable 5 launch in June, Mollick used the same approach to show three games: Snake, Strata, and Duino, each from a single prompt (9 June 2026). Now that same one sentence produced a wordless game with its own story, while all visuals are rendered directly in the browser: it contains no pre-made images.
Repeating the experiment costs model money. Fable is currently available as Claude Fable 5.1 in Claude Code and via the API, $10 per million input tokens and $50 per million output tokens (Anthropic, 01.09.2026).
UMBRA's code is not publicly available: as of 20.09.2026, it had not appeared in Mollick's public repositories, so it can only be recreated with a prompt.
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