Left to their own devices, an army of AI characters didn’t just survive — they thrived. They developed in-game jobs, shared memes, voted on tax reforms and even spread a religion. The experiment played out on the open-world gaming platform Minecraft, where up to 1000 software agents at a time used large language models (LLMs) to interact with one another. Given just a nudge through text prompting, they developed a remarkable range of personality traits, preferences and specialist roles, with no...