Deriving Character Logic from Storyline as Codified Decision Trees

Letian Peng, Kun Zhou, Longfei Yun, Yupeng Hou, Jingbo Shang


Abstract
Role-playing (RP) agents rely on behavioral profiles to act consistently across diverse narrative contexts, yet existing profiles are largely unstructured, non-executable, and weakly validated, leading to brittle agent behavior. We propose Codified Decision Trees (CDT), a data-driven framework that induces an executable and interpretable decision structure from large-scale narrative data. CDT represents behavioral profiles as a tree of conditional rules, where internal nodes correspond to validated scene conditions and leaves encode grounded behavioral statements, enabling deterministic retrieval of context-appropriate rules at execution time. The tree is learned by iteratively inducing candidate scene–action rules, validating them against data, and refining them through hierarchical specialization, yielding profiles that support transparent inspection and principled updates. Across multiple benchmarks, CDT substantially outperforms human-written profiles and prior profile induction methods, indicating that codified and validated behavioral representations lead to more reliable agent grounding.
Anthology ID:
2026.acl-long.568
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
12480–12509
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.568/
DOI:
Bibkey:
Cite (ACL):
Letian Peng, Kun Zhou, Longfei Yun, Yupeng Hou, and Jingbo Shang. 2026. Deriving Character Logic from Storyline as Codified Decision Trees. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 12480–12509, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Deriving Character Logic from Storyline as Codified Decision Trees (Peng et al., ACL 2026)
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https://preview.aclanthology.org/ingest-acl/2026.acl-long.568.pdf
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