Partner check

A partner check is a short routine done right before a climb starts, where the climber and belayer look over each other's setup rather than trusting their own work alone. It typically covers the climber's harness buckles being doubled back, the tie in knot being finished and dressed correctly, and the belay device being loaded correctly with the carabiner locked.

The point of doing this as a pair rather than solo is that a second set of eyes catches mistakes the person who made them is prone to miss, such as a harness buckle that looks fine at a glance but was never doubled back, or a locking carabiner left unlocked. Experienced climbers still do partner checks every single climb, since the routine itself is what prevents complacency from creeping in over time.

Skipping this step because a partner seems experienced, or because it feels awkward to check a stranger's gear at a gym, is a common way avoidable accidents happen. Making the partner check a fixed habit, rather than something reserved for beginners or new partners, matters more than any single piece of gear on the rack.