A robotic vehicle having a body with an internal volume. A plurality of extendable legs project outwardly from the body for supporting the body on a surface and for propelling the body, in at least a partial rolling motion, over the surface. A gimbal system is supported within the body. The gimbal system has a support platform that is moveable within at least two non-parallel planes. An actuator is supported on the support platform and is positionable by the gimbal system into different positions to actuate selected ones of the extendable legs, to thus assist in propelling the vehicle.