This article reviews the physics case for the ILC. Baseline running at 500 GeV as well as possible upgrades and options are discussed. The opportunities on Standard Model physics, Higgs physics, Supersymmetry and alternative theories beyond the Standard Model are described.
ILC Collaboration, Aarons, G., Cortina Gil, E., & et al. (2007). International Linear Collider Reference Design Report Volume 2: Physics At The Ilc. High Energy Physics - Phenomenology. Published. https://hdl.handle.net/2078.5/150738 (Original work published 2007)