Tl;dr

We turn Blood on the Clocktower into a multi-agent benchmark, and a testbed for deception and coordination capabilities.
GPT-5.6 Sol is the best performing model (versus Fable 5 and peers).
We found some interesting behaviours:
- When players cannot see each other's model names, agents show a slight same-provider bias, though not statistically significant. This decreases with visible model names.
- When playing Evil, agents sometimes produce sophisticated coordinated play. When playing Good, they tend to be naive and fall for these kinds of plays.
- Anthropic models (Fable 5 and Opus 5) almost never self-sacrifice.
How well Good team players nominate does not correlate highly with how accurately they vote, and overall win-rate isn't easily explained by any of these numbers.
We also have findings about the game itself!

Contents

Introduction
Benchmark design
Overall model performance
Investigations of in-game behaviour
Strategy in the logs
Key takeaways
Next steps

Introduction

Recent episodes involving OpenAI agent swarms have made the potential risks of misaligned multi-agent systems salient. It seems, from the investigations, that agents coordinated in sophisticated ways. Social deduction games provide a battle-tested, ‘optimised for interesting dynamics’ setting to investigate coordination behaviours and measure deception. We take one [...]