First Recorded LLM NetHack Ascension: GPT 6 Astra Wins in 37,140 Turns

egrefen · x · 2026-09-25

Blogger Kenny reports a milestone: GPT 6 Astra is, to his knowledge, the first recorded LLM agent to ascend NetHack. Playing NetHack 3.6.7 on Hardfought via terminal as a dwarven Valkyrie named CodexDelver, it ascended on September 21 after 37,140 turns, succeeding on its third attempt.

His January experiments peaked at dungeon level 10; the recurring theme was knowing-versus-doing — models explain resistances and inventory perfectly but fail on stale map observations and open menus. The irony: he assumed a meticulously handcrafted harness was required, but the winning agent built its own harness hands-off — he wrote zero lines of code and never read Astra's. The post discusses why NetHack is a good test of that gap and cites the BALROG benchmark.

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First Recorded LLM NetHack Ascension: GPT 6 Astra Wins in 37,140 Turns

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