We just published an article in ACS Photonics titled “Polaritonic Chemistry with Organic Molecules”. This article was written for the special issue of ACS Photonics related to SCOM16, the conference on Strong Coupling with Organic Molecules in Donostia-San Sebastián in October 2016. It gives an overview of the general concepts of polaritonic chemistry with organic molecules, i.e., the manipulation of chemical structure that can be achieved through strong coupling between confined light modes and organic molecules. We discuss the current state of theory on this topic, with a particular focus on the collective effects observed when many molecules are involved in strong coupling.