100% of the time. No exception. To those who do not, here are two real events ... both very close to me.

My brother fell from a 10' ladder stand. Concussion. Fractured skull. Broken neck. He was lucky to have not severed his spinal chord. Nerve damage left him forever at about a 50% loss of upper body strength. He remembers to this day no details of the fall. Investigation indicated that the home made ladder stand platform supports had been made from untreated pine and had rotted. They simply gave way.

A good friend was removing a rather large dead limb just before settling into his climber. The limb broke before he thought it would and knocked him backwards. He managed to slide his feet under a part of the frame of the lower section of the climber, otherwise would have tumbled out backwards. Already was severely injured. This guy was one heck of an athelete. But try as he might, he was unable upright himself. He hung there for about an hour hoping for help to come by. He felt as if he were going to pass out and feared shock was setting in. So he wriggled himself out and dropped about 15' into under brush. Dragged himself to his ATV. Drove to where he had cell service and called for help. Suffered a double compound fracture of his left leg just above the ankle, severe dislocation of his right ankle, broken collar bone, 2 broken ribs , punctured lung .... thankfully he survived, but will never recover fully from the ankle damage.

Neither were wearing (or had ever worn) a harness of any type.