— In this paper we will present the architecture of the planar biped robot “RunBot”. It has been developed on the basis of three hierarchical levels: Biomechanical, Local and Central. The biomechanical level concerns an appropriate biomechanical design of RunBot which utilizes some principles of passive walkers to ensure stability. The local level is a lowlevel neuronal structure which generates dynamically stable gaits as well as fast motions with some degree of self-stabilization to guarantee basic robustness. In the central level, we simulate a mechanism for synaptic plasticity which allows RunBot to autonomously learn to adapt its locomotion to different terrains, e.g. level floor versus up or down a ramp. As a result, the structural coupling of all these levels generates adaptive, fast dynamic walking of RunBot.