AI-Powered Interactive Legal Role-Playing Tool for Courtroom Advocacy Training

This paper presents an AI-powered interactive legal role-playing tool designed to simulate courtroom advocacy while continuously evaluating the legal quality of learner arguments. The system implements a two-stage Fast Brain and Smart Brain audit pipeline, where a fine-tuned BERT-based model assesses legal density and Gemini generates plain-English explanatory feedback. The platform generates Sri Lankan courtroom scenarios, manages five AI personas, and maintains autonomous dialogue through a heartbeat-driven engine. Model B achieves 98.28% accuracy and AUC-ROC of 0.9951. A reward-based response selection loop produces a 29.5% score uplift by selecting the highest-scoring of three generated candidates.