Deriving Character Logic from Storyline as Codified Decision Trees
Letian Peng, Kun Zhou, Longfei Yun, Yupeng Hou, Jingbo Shang
TL;DR
This paper tackles the brittleness and non-executability of traditional RP character profiles by introducing Codified Decision Trees (CDT), a data-driven framework that induces executable, situation-specific profiles from large-scale narrative data. CDT learns a hierarchical tree where internal nodes encode validated scene predicates and leaves store grounded behavioral statements, enabling deterministic retrieval of context-appropriate rules via CDT traversal. It couples recursive hypothesis-validation with clustering-based rule mining to produce compact, interpretable profiles that can be converted to textual wiki-like representations and generalized to open-domain interactions. Empirical results across fine-grained Fandom and Bandori benchmarks show CDT and its lightweight variant CDT-Lite outperform baselines and even human-written profiles, with strong data-scaling, relation modeling, and multi-modal extension potential, indicating practical impact for reliable, controllable RP systems.
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 on $85$ characters across $16$ artifacts, indicating that codified and validated behavioral representations lead to more reliable agent grounding.
