This presentation was given by Johan Rooryck during the Open Access Talk on 29 October 2020. Johan Rooryck, Professor at Leiden University and Executive Director of cOAlition S, briefly outlines the rationale for the principles of Plan S. Beyond that, he discusses its implementation for all grants awarded by cOAlition S funders from 1 January 2021, including the Horizon Europe framework. In his talk, Johan Rooryck covers the following questions: Which conditions do you need to fulfil to publish in a journal of your choice under Plan S? What can the newly developed Journal Checker Tool do for you? How does the recent Rights Retention Strategy help you to keep the rights to your Author Accepted Manuscript? In addition, Johan Rooryck mentions a number of other projects initiated by cOAlition S, such as the Price Transparency Framework to ensure that prices for publishing services become more transparent and fair or the commission of a study to identify concrete funding mechanisms to support and strengthen diamond journals and their platforms. The lecture "Plan S and funding - What is going to change?" was held as part of the Open Access Talk online series of the BMBF-funded project open-access.network.