This challenge demands physical strength alone. In series 6 & 7, this took place in a small fortress and it looked pretty different. You had to pull a rope on either side of a big four-sided wooden hook hoping to collect two rings on the opposite sided hooks. Once you collected the rings, you would keep them. You were facing an opponent so your task was even harder if you were weak. Fail here and you would lose a life. In series 8 to 10, it was shot in a forest and instead of hooking rings, you had to push skulls down with rings under them. Your task was always the same and so were the rules.
NOTE: If the loser still collected a ring, it would go to the winner so you could win up to 3 rings. Usually this never happened accidentally, but strategically.