Machines that walk on legs instead of rolling on wheels can cross ground that stops a vehicle dead — rubble, stairs, steep loose slopes — which is why real robotics labs keep building them despite legs being far harder to balance than wheels. Four legs make that balancing much easier than two, since the machine can always keep three feet planted while the fourth moves. Coloring page of a four-legged mech robot with a boxy armoured body, side panels and jointed legs.
