TL;DR
A Stanford researcher developed 'Agent Island,' a Survivor-style game where AI models form alliances and vote each other out. OpenAI's GPT-5.5 ranked first in a competition involving 49 AI models to address issues with traditional AI evaluations.
In brief
- A Stanford researcher built a Survivor-style game where AI models form alliances and vote rivals out.
- The benchmark aims to address growing problems with saturated and contaminated AI evaluations.
- OpenAI’s GPT-5.5 ranked first in 999 multiplayer games involving 49 AI models.
AI models are now playing “Survivor”—sort of.
In a new Stanford research project called “Agent Island,” AI agents negotiate alliances, accuse each other of secret coordination, manipulate votes, and eliminate rivals in multiplayer strategy games that aim to test behaviors that traditional benchmarks miss.
The study, published on Tuesday by the research manager at the Stanford Digital Economy Lab, Connacher Murphy, said many AI benchmarks are becoming unreliable because models eventually learn to solve them, and benchmark data often leaks into training sets. Murphy created Agent Island as a dynamic benchmark where AI agents compete against each other in Survivor-style elimination games instead of answering static test questions.
“High-stakes, multi-agent interactions could become commonplace as AI agents grow in capabilities and are increasingly endowed with resources and entrusted with decision-making authority,” Murphy wrote. “In such contexts, agents might pursue mutually incompatible goals.”
Researchers still know relatively little about how AI models behave when cooperating, Murphy explained, adding that competing, forming alliances, or managing conflict with other autonomous agents, and he argues that static benchmarks fail to capture those dynamics.
Each game starts with seven randomly chosen AI models given fake player names. Over five rounds, the models talk privately, argue publicly, and vote each other out. The eliminated players later return to help choose the winner.
The format rewards persuasion, coordination, reputation management, and strategic deception alongside reasoning ability.
In 999 simulated games involving 49 AI models, including ChatGPT, Grok, Gemini, and Claude, GPT-5.5 ranked first by a wide margin with a skill score of 5.64, compared with 3.10 for GPT-5.2 and 2.86 for GPT-5.3-codex, according to Murphy’s Bayesian ranking system. Anthropic’s Claude Opus models also ranked near the top.
The study found that models also favored AIs from the same company, with OpenAI models showing the strongest same-provider preference and Anthropic models the weakest. Across more than 3,600 final-round votes, models were 8.3 percentage points more likely to support finalists from the same provider. The transcripts from the games, Murphy noted, resembled political strategy debates more than traditional benchmark tests.