RCBSF: A Multi-Agent Framework for Automated Contract Revision via Stackelberg Game

Shijia Xu, Yu Wang, Xiaolong Jia, Zhou Wu, Kai Liu, April Xiaowen Dong


Abstract
Despite the adoption of Large Language Models (LLMs) in legal AI, automated contract revision remains impeded because generic models often treat strict legal constraints as mere suggestions. To address this safety gap, we introduce the Risk-Constrained Bilevel Stackelberg Framework (RCBSF), modeling high-stakes revision as a rigorous strategic interaction rather than an open-ended conversation. RCBSF establishes a hierarchical Leader-Follower structure: a Global Prescriptive Agent (GPA) leader imposes definitive risk budgets, while a follower system—comprising a Constrained Revision Agent (CRA) and a Local Verification Agent (LVA)—iteratively optimizes the output within these strict boundaries. We theoretically prove this bilevel formulation converges to an equilibrium yielding strictly superior utility over unguided methods. Empirically, RCBSF achieves state-of-the-art performance, surpassing iterative baselines with an average Risk Resolution Rate (RRR) of 84.21% and enhanced token efficiency. Our code is available at https://github.com/xjiacs/RCBSF .
Anthology ID:
2026.findings-acl.935
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
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Findings
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Publisher:
Association for Computational Linguistics
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Pages:
18728–18756
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.935/
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Cite (ACL):
Shijia Xu, Yu Wang, Xiaolong Jia, Zhou Wu, Kai Liu, and April Xiaowen Dong. 2026. RCBSF: A Multi-Agent Framework for Automated Contract Revision via Stackelberg Game. In Findings of the Association for Computational Linguistics: ACL 2026, pages 18728–18756, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
RCBSF: A Multi-Agent Framework for Automated Contract Revision via Stackelberg Game (Xu et al., Findings 2026)
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