Ok, I'll go ahead and explain how rolling is done in _EVERY_ MMORPG. The "random" function is basically a math calculation done on your PC time using the ctime library. However, in an MMORPG, the random function is performed on the server side and sent to the clients so it is based on the server's time. That means that the only way to guess a random is to be able to accurately know what the server's time says at any given time and perfectly time a random so that when the server's time when put into the function will bring out your desired roll.
In laymen's terms, a roll hack is next to impossible.