Claude Fable 5 Builds an Ink-Wash Roguelike From a Single Prompt in Five Hours

A developer instructed "Claude Fable 5," the model Anthropic released to the public on June 9, 2026, to "build the best game in one go," and about five hours later it returned a complete ink-wash (Chinese-painting style) roguelike, according to a report. The finished game featured custom art, original music evoking a guqin, multiple boss fights, a skill system and endgame content, and the model itself ran tests and fixed bugs using the browser-automation framework Playwright. In the underlying experiment, the developer provided a PRD (product requirements document) and a goal in a single shot, and two sessions of roughly five hours each consumed about 90% of the allotted tokens. Described as a defensive roguelike where "the finger becomes the brush and the stroke becomes the blade," it was shared alongside a video of actual gameplay.