RHex is a power autonomous, untethered hexapod robot with six actuators, one at each hip, enabling simple and robust operation. It uses a clock-driven, open-loop tripod gait for highly maneuverable locomotion, with legs rotating fully to avoid toe stubbing. RHex can traverse rugged terrain without terrain sensing, achieving speeds up to one body length per second and overcoming height variations exceeding its body clearance. Experimental results show its significant "intrinsic mobility." The robot's design includes a rigid body with six compliant legs, each with one revolute degree of freedom. It uses a compliant leg design that allows for full ground reaction force control, unlike wheels. RHex's control strategy uses a four-parameter family of controllers for forward and turning motion, with periodic desired trajectories for each hip joint enforced by local PD controllers. Simulation studies confirmed the feasibility of basic locomotion behaviors under practical actuation limitations. The experimental platform, RHex, has a rigid body with six compliant legs, each actuated by a Maxon DC motor. It was tested on various terrains, including carpet, linoleum, grass, and gravel, demonstrating high speed and maneuverability. RHex also successfully crossed obstacles and rough surfaces, showing its ability to navigate challenging environments. The robot's performance was evaluated in terms of speed, energy efficiency, and obstacle-crossing capability. RHex's design and control strategy enable robust and efficient locomotion over varied terrain, with potential for future improvements in performance and mechanical design.RHex is a power autonomous, untethered hexapod robot with six actuators, one at each hip, enabling simple and robust operation. It uses a clock-driven, open-loop tripod gait for highly maneuverable locomotion, with legs rotating fully to avoid toe stubbing. RHex can traverse rugged terrain without terrain sensing, achieving speeds up to one body length per second and overcoming height variations exceeding its body clearance. Experimental results show its significant "intrinsic mobility." The robot's design includes a rigid body with six compliant legs, each with one revolute degree of freedom. It uses a compliant leg design that allows for full ground reaction force control, unlike wheels. RHex's control strategy uses a four-parameter family of controllers for forward and turning motion, with periodic desired trajectories for each hip joint enforced by local PD controllers. Simulation studies confirmed the feasibility of basic locomotion behaviors under practical actuation limitations. The experimental platform, RHex, has a rigid body with six compliant legs, each actuated by a Maxon DC motor. It was tested on various terrains, including carpet, linoleum, grass, and gravel, demonstrating high speed and maneuverability. RHex also successfully crossed obstacles and rough surfaces, showing its ability to navigate challenging environments. The robot's performance was evaluated in terms of speed, energy efficiency, and obstacle-crossing capability. RHex's design and control strategy enable robust and efficient locomotion over varied terrain, with potential for future improvements in performance and mechanical design.