The AVCORP corpus: identifying and defending against deception based on propagation theory and theory of mind

The AVCORP corpus uses 5,000 annotated utterances from 250 Avalon games to train Qwen3-8B to identify deception; its best detector surpasses frontier models such as GPT-5.6 Sol and matches Claude Opus 5.5 on 25 held-out games. The corpus maps 37 strategies onto a 4x4 behavior matrix and includes reasoning traces with abductive hypotheses, suspicion levels and nested ToM beliefs. In 20 human games, every trained detector's F1 across all rounds was higher than that of untrained models.