Open Rubric System: Scaling Reinforcement Learning with Pairwise Adaptive Rubric

Wen Wang, Ruipeng Jia, Yunyi Yang, Yuxin Wu, Yongbo Gai, Siyuan Tao, Mengyu Zhou, Jianhe Lin, Xiaoxi Jiang, Guanjun Jiang


Abstract
We argue that robust alignment for non-verifiable tasks is fundamentally a principle generalization problem: reward should be guided by explicit, auditable principles rather than compressed into a learned scalar function. To operationalize this view, we present the Open Rubric System (OpenRS) , a modular, rubrics-based LLM-as-a-Judge framework built around Pairwise Adaptive Meta-Rubrics (PAMR) and lightweight Pointwise Verifiable Rubrics (PVRs). OpenRS is governed by an explicit meta-rubric—not a rubric itself, but a higher-level guideline that specifies how rubrics should be generated, which criteria to prioritize, and which failure modes are non-negotiable—and instantiates concrete adaptive rubrics on the fly by conditioning on the semantic differences between two candidate responses. It then performs criterion-wise pairwise comparisons and aggregates criterion-level preferences externally, avoiding pointwise weighted scalarization while improving discriminability in open-ended settings. Finally, we instantiate OpenRS as reward supervision in pairwise RL training. Empirically, OpenRS achieves state-of-the-art results on four reward-modeling benchmarks and yields stable gains when replacing scalar reward models in end-to-end RL.
Anthology ID:
2026.emnlp-industry.89
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Pepa Atanasova, Gholamreza Haffari, Minghan Wang
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
1501–1530
Language:
URL:
https://aclanthology.org/2026.emnlp-industry.89/
DOI:
Bibkey:
Cite (ACL):
Wen Wang, Ruipeng Jia, Yunyi Yang, Yuxin Wu, Yongbo Gai, Siyuan Tao, Mengyu Zhou, Jianhe Lin, Xiaoxi Jiang, and Guanjun Jiang. 2026. Open Rubric System: Scaling Reinforcement Learning with Pairwise Adaptive Rubric. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track, pages 1501–1530, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Open Rubric System: Scaling Reinforcement Learning with Pairwise Adaptive Rubric (Wang et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-industry.89.pdf