ASP2LJ : An Adversarial Self-Play Laywer Augmented Legal Judgment Framework

TL;DR

The paper introduces ASP2LJ, a novel framework combining adversarial self-play and case generation to improve legal judgment prediction, especially for rare cases, by enhancing lawyer argumentation and addressing data imbalance.

Contribution

It proposes an innovative framework, ASP2LJ, integrating case generation and adversarial self-play, along with a new rare-case dataset, to advance automated judicial decision-making.

Findings

Improved judicial prediction accuracy on simulated and rare cases.

Enhanced lawyer argumentation skills through adversarial self-play.

Public release of datasets and code for further research.

Abstract

Legal Judgment Prediction (LJP) aims to predict judicial outcomes, including relevant legal charge, terms, and fines, which is a crucial process in Large Language Model(LLM). However, LJP faces two key challenges: (1)Long Tail Distribution: Current datasets, derived from authentic cases, suffer from high human annotation costs and imbalanced distributions, leading to model performance degradation. (2)Lawyer's Improvement: Existing systems focus on enhancing judges' decision-making but neglect the critical role of lawyers in refining arguments, which limits overall judicial accuracy. To address these issues, we propose an Adversarial Self-Play Lawyer Augmented Legal Judgment Framework, called ASP2LJ, which integrates a case generation module to tackle long-tailed data distributions and an adversarial self-play mechanism to enhance lawyers' argumentation skills. Our framework enables a judge to reference evolved lawyers' arguments, improving the objectivity, fairness, and rationality of judicial decisions. Besides, We also introduce RareCases, a dataset for rare legal cases in China, which contains 120 tail-end cases. We demonstrate the effectiveness of our approach on the SimuCourt dataset and our RareCases dataset. Experimental results show our framework brings improvements, indicating its utilization. Our contributions include an integrated framework, a rare-case dataset, and publicly releasing datasets and code to support further research in automated judicial systems.