Needed for climbing. Only 1/3 being talent and 2/3 exercise it is very worth full to allow young children to experiment with climbing on different objects instead of. This is also a plead for good gymnastics lessons and more space outside for children to play physical games.
When climbing with half ropes, you use two ropes. As you ascend, clip one rope to protection on the left and the other to protection on the right. When done correctly, this allows the ropes to run parallel and straight, thereby reducing rope drag on wandering routes.