this would be a very simple mod that is crafted by using string and gives you a couple rope when you have this equipped you can left click onto the side or on top of a surface then if you want to jump down say a ravine it allows you to move up and down the sides of it. it will take the rope rite out of your inventory and let you climb up and down freely when you want to get rid of the rope simply left click an end and it will all pop back into your inventory.
rope an new use of string