In official server files you can have mages and fighters with different success rate etc
In java, you cannot edit that, but in off it's pretty easy...
The official rate if it's not editted is 2/3 chance for weapons and armor and for jewels, it's 1/3...
So, do not believe all the rumors about enchant exploits etc, it's server side, IT HAS NOTHING TO DO WITH CLIENTS OR PACKETS, they only packets that are sent during the enchant proccess are:
Message (success/fail)
And the weaponpacket changes and says that the weapon is +++ etc..