The spectacular astrophysics results obtained by the current IACTs demand a more sensitive observatory. The IACT technique is by now well established and, at least in the core energy range above 100 GeV, the performance and the limitations of current instruments are well understood. This allows a reliable extrapolation towards a next generation of instruments, providing vastly improved performance and increased flexibility to accommodate a large community of users. CTAO aims at a better sensitivity in the core energy range by roughly one order of magnitude. Three different sizes of telescopes will achieve a sensitivity covering a very wide energy range from 20 GeV (overlapping with space-based gamma-ray instruments such as Fermi-LAT) up to 300 TeV. The angular resolution below 0.05° above 1 TeV and 2 milli-Crab ux sensitivity (meaning that a flux in the TeV region 1000 smaller than the Crab Nebula measured one would be detectable at 2σ con dence level) in a few years for the Galactic Plane gamma-ray survey. CTAO will reveal finer detail in the sources and unprecedented detection rates, enabling researchers to track transient phenomena on very short time scales.

Angular resolution of Northern and Southern CTA sites and existing and future gamma-ray observatories