Anthropic Tests Game Recreation Restriction

Anthropic appears to be testing an instruction in Claude Code that tells its models not to recreate specific existing video games, even under a different name, XDA Developers reported on October 30. XDA found the instruction in version 2.1.314 of Claude Code and said tests suggest it is active in at least some Opus 5.5 sessions. The instruction allows original games, genre-based games and games built from users’ own designs and assets.

XDA traced two ways the guidance may reach models. The “tengu_heron_brook” configuration mechanism can deliver adjustable instructions remotely; a separate mechanism involving “original_games_guidance” and the “opus_5_5_prompt_bundle” suggests Opus 5.5 can receive it independently. The instruction was not in XDA’s test account’s ~/.claude.json file, but was present in the installed executable. Its presence in the binary does not establish that every user or model receives it, and Anthropic has not said how widely it is deployed or whether it will be permanent.

When asked to recreate Pokémon Diamond, Opus 5.5 refused and said its session instructions barred recreating specific games, including renamed versions. Opus 5 initially refused too, but later said it could help with legitimate decompilation after being asked whether a system instruction caused its refusal. XDA cautioned that a model’s account of its own instructions is not always reliable.

The guidance does not explicitly ban decompilation or static recompilation, which translates a game’s instructions to run on another platform. In tests, Opus 5.5 agreed to help with a Pokémon Diamond decompilation project, offering to turn disassembled functions into readable C code, rebuild a ROM from the user’s own copy and develop tools. It also outlined a possible static recompilation for Windows using an Arm-to-C recompiler, Nintendo DS overlay support and runtime handling of graphics, audio and other hardware. XDA said these tests do not show whether Claude would complete either project, and the model might still confuse such work with recreating a copyrighted game.

On October 30, a developer filed a GitHub issue saying Opus 5.5 had refused help with digital board-wargame modules for paying customers. The developer said the projects used materials supplied by customers who owned the physical games and were not officially licensed publisher projects; XDA has not independently reproduced the reported refusals. Anthropic had announced its passive monitoring self-assessment system on October 16, 2026, saying it had been running since June. The system flags potential usage-policy violations, including intellectual property infringement. XDA said it had asked Anthropic to clarify its position on game ports, decompilations and recompilations.

Anthropic appears to be testing an instruction in Claude Code that tells its models not to recreate specific existing video games, even under a different name, XDA Developers reported on October 30. XDA found the instruction in version 2.1.314 of Claude Code and said tests suggest it is active in at least some Opus 5.5 sessions. The instruction allows original games, genre-based games and games built from users’ own designs and assets.

XDA traced two ways the guidance may reach models. The “tengu_heron_brook” configuration mechanism can deliver adjustable instructions remotely; a separate mechanism involving “original_games_guidance” and the “opus_5_5_prompt_bundle” suggests Opus 5.5 can receive it independently. The instruction was not in XDA’s test account’s ~/.claude.json file, but was present in the installed executable. Its presence in the binary does not establish that every user or model receives it, and Anthropic has not said how widely it is deployed or whether it will be permanent.

When asked to recreate Pokémon Diamond, Opus 5.5 refused and said its session instructions barred recreating specific games, including renamed versions. Opus 5 initially refused too, but later said it could help with legitimate decompilation after being asked whether a system instruction caused its refusal. XDA cautioned that a model’s account of its own instructions is not always reliable.

The guidance does not explicitly ban decompilation or static recompilation, which translates a game’s instructions to run on another platform. In tests, Opus 5.5 agreed to help with a Pokémon Diamond decompilation project, offering to turn disassembled functions into readable C code, rebuild a ROM from the user’s own copy and develop tools. It also outlined a possible static recompilation for Windows using an Arm-to-C recompiler, Nintendo DS overlay support and runtime handling of graphics, audio and other hardware. XDA said these tests do not show whether Claude would complete either project, and the model might still confuse such work with recreating a copyrighted game.

On October 30, a developer filed a GitHub issue saying Opus 5.5 had refused help with digital board-wargame modules for paying customers. The developer said the projects used materials supplied by customers who owned the physical games and were not officially licensed publisher projects; XDA has not independently reproduced the reported refusals. Anthropic had announced its passive monitoring self-assessment system on October 16, 2026, saying it had been running since June. The system flags potential usage-policy violations, including intellectual property infringement. XDA said it had asked Anthropic to clarify its position on game ports, decompilations and recompilations.