Integrated Assessment Models (IAMs) provide foresight for long-term climate change mitigation strategies. The majority of IAMs focus on the transformation of the energy system; away from fossil fuels towards low-carbon technologies. Focusing on one mitigation sector alone, however, ignores the competition for land and materials as well as amplifying and inhibiting feedback mechanisms between the systems. Therefore, an increasing number of scientists are calling for a better understanding and exploitation of mitigation potentials immanent in land-based carbon sequestration, low-carbon materials, climate-safe technologies, and their mutual interdependencies (Pauliuk et al. 2017; Schandl et al. 2020; Harper et al. 2018; Griscom et al. 2017). We present a new, open-source IAM called SuCCESs (Sustainable Climate Change mitigation strategies in Energy-land-materials Systems) that calculates long-term scenarios in energy, land-use and materials systems. The representation of each system is condensed in comparison to dedicated land and energy models, to focus the computational power on the full integration and coupling of the subsystems, which allows joint optimization of mitigation measures while accounting for the interdependent feedback effects between the systems. Through that, SuCCESs also offers a broader scope than existing models by integrating multiple systems into a single package, which is then solved through intertemporal optimization. The partial equilibrium approach of SuCCESs simulates efficient markets and policies by finding a cost-minimizing solution that satisfies the projected global demand for energy, materials and food under available resources, assumed technological progress and prescribed environmental policies.