Claude Refuses Pokémon Fan Projects After Reproduction Rule Update
Anthropic's Claude now refuses to build game assets using Pokémon sprites, developer BigKidNation reported on November 11 and detailed on November 12. Claude said the file's storage location does not matter.
1 source 3h ago
Reporting from 1 source: Automaton.
Why it matters
The prompt that started as a ban on cloning existing games now reads as a ban on a specific franchise's assets, which puts unofficial fan projects in the same category as reproduction games.
Key Facts
- Claude said Pokémon sprites would not be used when building a new game, and that the file's storage location does not matter.
- On October 30, X user chasm reported a Claude Code prompt managed by a flag called tengu_heron_brook that bans reproductions of specific existing games.
- Addy Osmani, who is involved in Claude Code development at Anthropic, acknowledged the addition of the prompt.
- Retrododo tests found Claude refused to draw Pokémon characters or copy designs as SVG or sprites, and refused logos and names.
The refusal follows an October 30 change to Claude Code, managed by a flag called tengu_heron_brook, that bars reproductions of specific existing games. Retrododo tests found Claude also refused Pokémon characters, logos, and names.
The rule arrived in stages. On October 30, X user chasm reported that Claude Code had gained a prompt, managed by a flag called tengu_heron_brook and not disableable by users, that blocks reproductions of specific existing games even when the title is changed or the work is presented as original. Addy Osmani, who works on Claude Code at Anthropic, acknowledged the addition.
Then the criteria got narrower. The tengu_heron_brook text now lists name, characters, art, music, stages, and appearance as the things that define a reproduction. BigKidNation's exchange shows Claude applying that list to Pokémon sprites in a fan game, and Retrododo's tests found refusals extending to characters, logos, names, and SVG or sprite copies.
Written with AI by Yomimono from the 1 cited source below, including Japanese-language reporting where cited. See our editorial policy.
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