The textbook "Unjust Enrichment" by H.-G. Koppensteiner offers a comprehensive analysis of civil law in the context of enrichment. It addresses the fundamental principles and the various performance conditions that are crucial for the legal assessment of enrichment claims. The structure of the book is clearly organized and includes several chapters that deal with specific aspects of enrichment, including the definition of the enrichment claim and its legal consequences. Additionally, the work contains a subject index as well as a list of abbreviated cited literature, which facilitates research and understanding of the complex subject matter. This book is a valuable resource for students and professionals in the fields of business and law who wish to engage with the intricacies of civil law.