BrAIcht, a theatrical agent that speaks like Bertolt Brecht's characters
This study addresses the challenge of controllable dialogue generation that faithfully reproduces Bertolt Brecht’s distinctive dramatic character language style. To this end, we introduce BrAIcht—the first dialogue agent explicitly designed for German theatrical style transfer. Methodologically, we construct a novel training corpus by integrating Brecht’s complete oeuvre of 29 plays with 907 stylistically aligned German dramas; fine-tune the German-adapted 7B-parameter LeoLM (a Llama-2 derivative) via QLoRA for efficient few-shot adaptation. Crucially, we propose a dual-metric evaluation framework combining BLEU and perplexity to jointly assess stylistic fidelity and linguistic fluency. Experimental results demonstrate that BrAIcht significantly outperforms all baselines on both metrics, confirming the feasibility of precise theatrical style transfer under low-resource conditions. This work establishes a scalable technical paradigm bridging digital humanities and interactive theatre.