Procedural rules and judicial practices: a good or bad match for transparency?

This article investigates how judicial practices affect the functioning of international courts and the transparency of procedural rules governing litigation before them. International courts have indeed embraced informal practices and soft law instruments more frequently, in addition to using traditional procedural sources (eg Treaties, Statutes, and Rules of Procedure). These informal practices encompass recommendations and procedural soft rules, presenting practical advantages while giving rise to transparency-related concerns. When practices remain unwritten, they become challenging to access and interpret. Conversely, through improving access to judicial practices, soft regulations raise concerns over their legal value and the complexity they add to the system. This article uses a comparative empirical approach to analyse the procedural systems of three selected international pilot courts to address these issues. Ultimately, the article discusses how formal rules and practices shape transparency and legal certainty within international courts’ procedural normative systems.