According to Ethan Mollick on X, Anthropic’s Claude Opus 4.6 passed his long-running “Lem Test” by producing an impossible poem in multiple strict forms, including a 6-line poem, a sonnet, and a sestina, demonstrating advanced controllable creativity and adherence to literary constraints. As reported by Mollick, he has run this test since the GPT-3.5 era, making Opus 4.6’s performance a meaningful step-change over prior models in constrained generation. According to Mollick’s thread, this result highlights business opportunities in high-precision content automation, from marketing copy and branded storytelling to complex creative workflows that require structure, tone, and meter control. As noted by Mollick, the Lem-inspired benchmark underscores rising model reliability in following intricate instructions, a capability enterprises can leverage for production-grade editorial tools, game narrative design, and education content generation where format compliance is critical.