Belay anchors are a fundamental part of any multi-pitch lead climbing system. The failure of a belay anchor under the force of a fall is likely to produce injuries, and in an unprotected leader fall, death. Climbers should make every attempt to construct belay anchors that can withstand the force of any possible fall.

Author and climbing guru John Long suggests that given the quality of modern climbing ropes, a normal-sized climber taking the longest possible fall cannot generate a force exceeding 11kN (1993). The size of the climber, type of climbing rope (static or dynamic), and the severity of the fall (fall factor) all combine to determine the amount of force that a falling climber can put on a belay anchor.