This book documents the proceedings of the 3rd IAPL-MPI Post-Doctoral Summer School, which was held in Luxembourg from July 1st to 4th, 2018. The Summer School aims at bringing together outstanding young post-doc researchers of any nationality dealing with European, international and comparative procedural law, as well as with other relevant mechanisms for dispute resolution. It not only gives them an opportunity to openly share and discuss their current research project with other young colleagues, but also with experienced law professors, who guide them, comment on their projects and advise them on how to proceed. This fruitful mix of generations is at the heart of the project, which dealt with both procedural and substantial domestic law, comparative law, European law and international law.