• When I am leading, I will be carrying a lot of climbing paraphernalia: carabiners and runners, plus the metal devices known as chocks, which can be secured into the rock as points of protection.
• After climbing up, say, 30 feet, I will place protection. The placement might make use of a tree or of a crack in the rock that I can slip a chock into. I'll attach a runner to the tree or to the chock and then clip the climbing rope into a carabiner that is attached to the runner; then I'll continue climbing.
• If I fall after climbing up another 10 feet, I will drop a total of only 20 feet before tension goes on the rope and your belay brings me to a stop. The rope will not unwrap from your body regardless of which hand you are belaying with, because the force on you will be upward.
• I may go on to establish a number of points of protection before I get to the next belay spot.

The severity of a fall-and the difficulty you will have in stopping it-depends partly on my weight but also on the amount of friction created as the rope travels through pieces of protection and around obstructions (the more friction, the easier it is to stop the fall) and on how much I bounce and slide down the rock rather than falling freely.

The severity of the fall also depends significantly on something called the fall factor - the ratio of the length of the fall to the length of rope between belayer and climber.

• If I fall from 10 feet beyond my last piece of protection with 40 feet of rope between us, I will fall 20 feet before your belay begins to stop me.
• The fall factor is the length of the fall divided by the length of rope between you and me: 20 divided by 40, for a fall factor of 0.5.
• The higher the fall factor, the higher the force of the fall. Despite what common sense might tell you, the mere length of a fall by itself has no effect on the maximum force of the fall (although it does affect the length of time the forces are there).