Anthropic confirms Claude Code will refuse to clone games

Anthropic has confirmed that it changed Claude Code so the AI coding tool will decline to rebuild other people's games. The company said it did this because using Claude to infringe intellectual property breaks its usage policy. The change comes after weeks of worry among independent developers that AI tools now let copycats clone a game and release it before the original is out. Game Developer reported the change.gamedeveloper.com

Two sentences in the prompt

The rule was first noticed by an X user called Chasm, who said it was pushed around October 27 under an internal flag named "tengu_heron_brook." According to Game Developer, the rule reads: "Do build original games, games in a genre, and games from the user's own designs and assets. Do not build a recreation of a specific existing game, even if it is renamed or called original." Users cannot turn it off.gamedeveloper.com

An Anthropic spokesperson pointed reporters to a statement on X from Addy Osmani, a member of Anthropic's technical staff. "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. He said original games, genre games and games made from a user's own designs "are meant to keep working," and that Anthropic would "continue to iterate to ensure we're striking the right balance".gamedeveloper.com

The rule doesn't always work as intended. One developer at Conflict Simulations LLC said in a GitHub issue that Claude refused work on board-wargame adaptations he described as licensed, though the cause is still unclear. Game Developer noted that safety limits on AI tools can often be dodged with clever wording, and that people who want to make clones can switch to open-weight models that have no such limits.kingy.ai

Studios pull back on demos

PC Gamer linked a recent wave of quickly made clones and decompiled games on Steam and Roblox to the release of Claude Opus 5.5. Digital Sun, the Valencia studio behind Moonlighter, cancelled a public Steam playtest of its game ReVamp. The studio said it had been "concerned by recent news of games being reverse-engineered, cloned and published before the original is even out". Instead, it started a smaller Discord playtest on October 29 and hopes to open a public test around January, ahead of a March 25, 2027 launch. Another studio, Alliance Arts, also held back a planned demo over fears of cloning.videogameschronicle.com+3

Pressure on storefronts

Developers have asked Valve how Steam will stop clones from pushing out their games. Valve gave developers in South Korea a rare explanation this week. A GamesIndustry.biz opinion piece argued that Steam's open system, where any game can launch after a small fee, "is on the verge of collapse" because AI makes poor-quality games so cheap to produce.gamesindustry.biz+1

Digital Sun's own message summed up the bind indie studios are in: "Showing games early is how indies get seen and find the fans who keep us going, so we hope platforms keep strengthening protections for original work".timeextension.com