The aim of the report „Transformative Agreements: Overview, Case Studies, and Legal Analysis” is to present the current situation regarding ‘transformative agreements’ understood as a means of transitioning from a subscription-based model of scientific publishing to full and immediate open access. In chapter one, the authors present transformative agreements in the context of Plan S; in chapter two, they outline the current state of negotiations and agreements between scientific institutions and publishers in various countries; in chapter three, they provide legal analysis of the agreements from the ESAC Transformative Agreement Registry. Chapter four consists of three case studies (Germany, Norway, Sweden); finally, chapter five is devoted to recommendations. The report is available under Creative Commons Attribution 4.0 International license (CC BY).