Anthropic has updated Claude Code’s system prompt to prevent the AI tool from being used to recreate existing video games, as reported by Tom’s Hardware. Retro gaming is currently being overrun with AI-made decompilations, recompilations, and ports, but while Anthropic will still let people use Claude Code to make games, it doesn’t want people to use it for direct clones.
Last week, a user on X posted a screenshot allegedly showing two new sentences added to Claude Code’s system prompt: “Do build original games, games in a genre, and games from the user’s own designs and assets. Don’t build a recreation of a specific existing game, even if it is named or called original.”
Anthropic’s Addy Osmani, in a reply, didn’t confirm that specific language but did say that the company had updated the prompt in Claude Code on Opus 5.5:
We added two sentences to Claude Code’s prompt on Opus 5.5 to steer it away from recreating someone else’s specific game because using Claude to infringe IP is against our usage policy.Original games, genre games, and games built from your own designs and assets are meant to keep working.We’ll continue to iterate to ensure we’re striking the right balance. In the meantime, if Claude turns down something that’s yours, send it my way.
We’ve asked Anthropic if it has or will be updating other Claude system prompts as well.