The idea of the Wave Run-up Simulator is based on the experiences with the Wave Overtopping Simulator. It is possible to simulate wave tongues overtopping a dike crest in reality. It must also be possible to simulate waves in the run-up and run-down zone of the seaward slope. This is the zone after waves have broken and when they rush-up the slope. The present report describes the idea of the Wave Run-up Simulator, why it is useful to develop the machine, to perform research with it and to develop a prediction method for slope strength. In fact, a prediction method can already be developed from the cumulative overload method, which was developed on the basis of results with the Wave Overtopping Simulator. It also means that tests on the seaward slope will be done for validation purposes only. The second part of the report describes in detail what is known about the movement of waves in this run-up zone and what actually the Wave Run-up Simulator has to simulate