TLDR: A new system called FURINA-Builder creates highly customizable role-playing benchmarks for large language models (LLMs) by simulating multi-agent dialogues. It allows for diverse characters and scenarios, and its resulting benchmark, FURINA-Bench, reveals that while reasoning improves LLM role-playing performance, it also increases hallucinations, highlighting a trade-off between performance and reliability.
Large language models, or LLMs, have made remarkable strides in conversational artificial intelligence, particularly in role-playing tasks. These advanced agents are now widely used on platforms where users can interact with diverse characters. However, the rapid evolution of LLMs means that existing benchmarks for evaluating their role-playing abilities quickly become outdated. These older benchmarks often suffer from a narrow scope, rigid interaction methods, and limited adaptability to new scenarios and character types.
To address these limitations, researchers have introduced a novel system called FURINA-Builder. This innovative multi-agent collaboration pipeline is designed to automatically construct fully customizable role-playing benchmarks at any scale. It’s the first benchmark builder in the role-playing field that allows for adaptable assessment of arbitrary characters across diverse scenarios and prompt formats.
How FURINA-Builder Works
The FURINA-Builder operates through a sophisticated multi-agent system. It simulates dialogues between a ‘test character’ (the LLM being evaluated) and other ‘scene characters’ drawn from a carefully curated character-scene pool. An LLM ‘judge’ then plays a crucial role, selecting specific evaluation dimensions and refining the test character’s responses into final utterances for the dialogue.
The pipeline consists of three main components:
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Character-Scene Pool: This is a vast repository of authentic dialogue scenarios. When a test character is introduced, the system samples a scenario from this pool, allowing the test character to interact with the scene characters within that setting.
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Simulation: During a dialogue simulation, a ‘director model’ iteratively decides which character speaks next or when the conversation should end. For the test character’s turn, candidate responses are generated by both a ‘source model’ (the primary test driver) and a ‘base model’ (a reference for performance). The system also uses a ‘Dynamically Weighted Random Selection’ algorithm to ensure that all evaluation dimensions are covered evenly over time.
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Selection: For each turn of the test character, the LLM judge selects the most appropriate evaluation dimension (e.g., Context Reliance, Factual Recall, Reflective Reasoning, Conversational Ability, Preference Alignment). Based on this dimension, the judge uses chain-of-thought reasoning to rate the candidate responses from the source and base models. This mechanism ensures that only high-quality, coherent dialogue trajectories are maintained, and each test utterance is assigned a relevant evaluation criterion.
Introducing FURINA-Bench
Using this powerful pipeline, the researchers built FURINA-Bench, a new comprehensive role-playing benchmark. This benchmark uniquely features both established characters (those with well-defined personas from existing works) and synthesized characters (newly created from scratch). It’s the first to unify these two character types in group chat scenarios and systematically examine both reasoning and role-playing hallucinations.
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Key Findings from Evaluating LLMs
Extensive evaluations of cutting-edge LLMs on FURINA-Bench revealed several important insights:
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Top Performers: For English role-playing tasks, the ‘o3’ model achieved the best overall performance. In Chinese tasks, ‘DeepSeek-R1’ demonstrated the strongest results.
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Scaling Benefits: Models like the Qwen3 series showed clear performance improvements across all evaluation dimensions as their scale increased.
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Established vs. Synthesized Characters: Across all models, established characters consistently outperformed synthesized ones. This suggests that dedicated training is crucial for strong role-playing capabilities, and reasoning abilities further widen this gap.
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Hallucinations and Reasoning: Interestingly, the study found no simple relationship between model scale and hallucination rates. More critically, while reasoning capabilities generally improve role-playing performance, they simultaneously increase the severity of role-playing hallucinations. This suggests a trade-off: more aggressive response strategies and extended thinking processes can lead to more factual or faithfulness errors.
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Performance-Reliability Trade-off: The research uncovered a broader ‘Pareto frontier’ between role-playing performance and reliability (defined as the inverse hallucination rate) for all LLMs. High-performing models often compromise reliability, while highly reliable models tend to be more conservative, suppressing overall performance. This highlights a core challenge for current LLMs: achieving simultaneous gains in both performance and reliability.
These findings demonstrate the effectiveness of FURINA-Builder and the challenging nature of FURINA-Bench, laying a strong foundation for future research on role-playing evaluation. The builder and benchmark are set to be released soon, promising to advance the field of conversational AI. For more details, you can refer to the full research paper here.


