In this work, the Author reconstructs and analyzes the institutional practice of perizia contrattuale. It can be called also expert determination, and It consists in a mechanism through which two subjects commission one or more third parties with specific technical-scientific skills – so called “periti,” field-experts – to verify a relevant technical matter in a legal relationship or a controversy. The verification is considered binding by the parties involved. The “history” about the phenomenon in question shows that it has been always compared to arbitraggio and arbitration. In short, the work is organized in six chapters. The first chapter begins with a short investigation into the historical context about arbitration and arbitraggio,...