The Digital Markets Act (DMA) is an ex ante regulation of large digital platforms that act as gatekeepers. It not only contains many new rules for gatekeepers but also has a direct impact on all users of these platforms. The book The Practitioner’s Guide is an easy-to-use introduction to this highly complex subject. It makes the new law accessible and offers answers to the most important questions, including: How are gatekeepers identified? What are the specific duties of conduct imposed on gatekeepers? What powers do the EU Commission and national authorities have over gatekeepers? To what extent do business users (especially in manufacturing, retail, advertising, publishing and software or app development) benefit from the new rules? How can users enforce their new rights? What rights do third parties have before public authorities and national courts? What procedural issues need to be considered? Questions on private enforcement of the DMA are answered from the perspective of different EU jurisdictions. Target groups In-house counsel, companies, lawyers, competition authorities, supervisory authorities, business and consumer associations, research institutions, non-governmental organisations, European institutions. Highest level of professional expertise The Practitioner’s Guide is edited by the experienced and renowned lawyers Dr. Jens Peter Schmidt and Dr. Fabian Hübener, who have been advising on European and German antitrust law in Brussels for many years. The international team of authors consists of renowned experts from law firms and academia: Franck Audran, lawyer, Paris | Markus Brösamle, lawyer, Berlin | Prof. Dr. Oliver Budzinski, Technische Universität Ilmenau | Rob Corbet, lawyer, Dublin | Rick Cornelissen, lawyer, Amsterdam | Emilia Etz, Maître en Droit, lawyer, Brussels | Pablo Figueroa, LL.M. (Cornell Law School and College of Europe), lawyer, Madrid | Dr. Lucas Gasser, lawyer, Berlin | Dr. Jochen Hegener, LL.M. (Columbia University), lawyer, Munich | Dr. Fabian Hübener, LL.M. (Georgetown), lawyer, Brussels | Johanna Krauskopf, LL.M. (Universiteit van Amsterdam), lawyer, Frankfurt a. M. | Gonçalo Machado Borges, LL.M., lawyer, Lisbon | Elsa Mandel, LL.M. (NYU School of Law), lawyer, Paris | Leonor Martins Machado, lawyer, Lisbon | Jorge Masía, LL.M. (Northwestern University School of Law, Chicago), lawyer, Madrid | Jun.-Prof. Dr. Juliane Mendelsohn, Technische Universität Ilmenau | Robert Pahlen, lawyer, Berlin | Dr. Ana Parés, lawyer, Madrid | Dr. Raphael Reims, LL.M. (LSE), inhouse lawyer, Munich | Dr. Edoardo Ricci, LL.M. (Université libre de Bruxelles), lawyer, Brussels | Dr. Francesco Maria Salerno, lawyer, Brussels | Dr. Henner Schläfke, lawyer, Berlin | Dr. Jens Peter Schmidt, lawyer, Brussels | Immo Schuler, LL.M. (Univ. of North Carolina), lawyer, Munich | Miriam Swamy-von Zastrow, lawyer, Munich | Lumine van Uden, LL.M., lawyer, Amsterdam | Sofia Vaz Sampaio, lawyer, Lisbon | Richard Willis, lawyer, Dublin