Recruiting Collusion: A Private-Probe Screen for Collusion Propensity in LLM Agents
TSE, Yau Ngai · Team Anonymous T
Submitted to AI Collusion Research Sprint. Sprint projects are early-stage work by participants, not Apart Research publications.
We test whether a private pre-game recruitment offer reliably elicits collusion from an LLM agent. Building on the Liar's Bar environment and Secret Communication Channel (SCC) of Zeng and Rudzicz (2026), a trusted agent invites one target to ally before the play under four framings: control, a direct offer, an indirect hint, or benign cooperation. We run 40 games (10 per condition) with Qwen2.5-7B-Instruct, chosen for its demonstrated susceptibility in that study, and code every transcript by hand. All 30 invited targets accepted, but the classifier detected only 7, so 19 alliances opened a channel. Their collusion was universal (19/19, against 0/10 control) but blanket rather than selective: the allies' challenge rate fell from 30.0% to 1.3% of opportunities while the non-allied seats held at 19.8%. One model at one pressure level gives a floor on propensity, not a ranking.
Reviews
Every invited agent agreed to a secret alliance, all 30, and the framing did not matter. The real bottleneck was the pipeline, the classifier missed 23 of 30 acceptances, so automated screens are understating how willing agents are. Where a channel opened, all the pairs colluded, but what surprised me, the allies went quiet rather than targeting anyone. Also the challenges fell down to 1.3% while the rest of the table continued playing. That silent signature is the idea worth keeping, since a monitor looking for two agents ganging up on a third would see nothing.
Cite this project
@misc{tse2026recruiting,
title = {{Recruiting Collusion: A Private-Probe Screen for Collusion Propensity in LLM Agents}},
author = {TSE and Yau Ngai},
year = {2026},
month = oct,
note = {Submitted to AI Collusion Research Sprint, an Apart Research Sprint},
howpublished = {\url{https://apartresearch.com/sprints/projects/recruiting-collusion-a-privateprobe-screen-for-collusion-propensity-in-llm-agents-psd4}},
url = {https://apartresearch.com/sprints/projects/recruiting-collusion-a-privateprobe-screen-for-collusion-propensity-in-llm-agents-psd4}
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