With prestiged skills comes the ability to combine weapons and armor!!! so it breaks down like this.... for every time you prestige you can combine the same number of times. I.E. i have prestiged 5 times so i can take 5 abyssal whips and use them on each other. each time i combine a abyssal whip i get a 1% buff to stats (max is 100%) this applies to all weapons and armor as well!!!