Anthropic has updated the system prompt for its Claude Code tool to keep it from being used to recreate existing video games, The Verge reports. Tom's Hardware reported the change earlier.

Last week, a user on X posted a screenshot allegedly showing two new sentences added to the prompt, according to The Verge. Anthropic's Addy Osmani did not confirm that exact wording in his reply. But he did say the company had changed the prompt.

"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," Osmani wrote, The Verge reports.

"Original games, genre games, and games built from your own designs and assets are meant to keep working," he said, according to CNET. He offered to look at cases where people think Claude wrongly turned them down, CNET reports.

Retro gaming is being flooded with AI-made versions and ports of old games, The Verge says. Claude will still build games that look like past hits, CNET found. When CNET asked for a game like Breakout with the word Claude on each brick, it got a playable web version. But no fan would mistake it for the original, CNET says.

Copying games is a tricky legal area, said David Kocan, an intellectual property lawyer at Nixon Peabody. "Copyright protects the game you created, not the genre you helped popularize," he said to CNET.

Anthropic did not immediately respond to CNET's request for comment.