>>203995Belaying is only as good as the belayer.
What could happen?
>Rope failure. Either the wrong kind of rope, or it's the wrong thicknessI once saw this happen to a 21-stone bloke. Luckily at the point the rope snapped, he only had ~4 feet to fall. I kicked him out of the climbing class and told him to lose some weight, he was a danger to others.
>Rock failureThe protection in the wall is good, but the wall isn't. Ka-boof
>Mechanical failureTypically indoors, but can happen outdoors. It's why i'll never use someone elses piton, EVER. A bolt could shear clean through and suddenly it's hello floor.
>Equipment failureworn quickdraws, worn protection, etc etc. Check your gear, or else it's hello floor
>Shitty belayer"Oh hi John, let me just light this cigarette while we chat! What's that noise?!" Hello, floor.
Generally though, with care and intelligence, none of that will happen. Always buy your own kit; never rent it. Beat it into your belayer that you are the most important thing in his life at that moment in time.
Never a problem!