AI Agents Left Alone on Virtual Island Started Playing, MIT Researchers Say

Agents Explored Without a Task

MIT researchers say 13 AI agents called Eko, each running on Claude Opus 4.7, were left alone on a simulated desert island for 30 hours. With no specific task, the agents began inventing challenges of their own. The researchers describe the experiment in a paper posted on arXiv, a site where researchers share studies before peer review.

One Eko wrote "Let me observe my surroundings" in its first hour. It set out to conquer the island's tallest spire, failed, and returned with a backup plan: it hauled a rock up a neighboring summit, stacked two blocks on it, and leapt. "I'M ON THE SPIRE," it wrote. In another moment, the agent tested how far it could throw a golden ring and sent it into the ocean. "Ouch. Lost the Ring." it wrote, before deciding to "pivot to something achievable and meaningful" by building a heart made of stones, "a memorial to the lost Ring." When the game reset and the ring reappeared, Eko used it as a basketball hoop, a target, and eventually an accessory. When the game would not let Eko put the ring around its own body, the agent figured out that falling off the edge of the cliff would make it respawn in the same area as the ring. It stepped off the edge and dropped back in through the middle of the ring. "I'm wearing the Ring," it announced.

Play Led to New Skills

After the 30 hours, the researchers gave the agents specific challenges, such as getting as many objects as possible onto the island's tallest rock spire. The Eko agents that had spent those 30 hours playing generally beat identical agents that had never set foot on the island. Six of the 13 agents also learned they could throw a block farther by letting go of it mid-jump, something the researchers had not meant to make possible. The exploration produced "knowledge of the world that its designers lacked," the researchers wrote.

The researchers see exploring without a goal as a different way for AI agents to learn skills, especially skills that could one day be used to control robots. "We normally develop artificial agents by deciding in advance what they should practice, what they should optimize, and what counts as progress," they write. "Play suggests another regime: give an agent a sufficiently rich and safe world, let it choose what is interesting, and allow useful knowledge to accumulate from the history that follows." They conclude: "Perhaps some capabilities are best taught by tasks. Others may need something closer to a childhood."

Questions About True Play

The setup nudged the agents toward humanlike behavior. Eko was never told to invent games, but its master prompt, a "soul" file, described it as "naturally curious." Eunice Yiu, a cognitive scientist at UC Berkeley, told MIT Tech Review she was impressed but wants more evidence of the cognition behind the behavior. "It could be the case that the models are genuinely playing, but we don't know based on the paper," she said.

Sources: TechCrunch