Many people have enchanting rituals that they like to do to increase their chances of success (its a psychological effect).
The fact is on most servers theres a 50-75% chance of success based on the type and grade of the weapon.
After that, its simply based on the random number that your CPU generates at the precise moment you press the OK button for enchanting.
In my server (l2forever) when you get jailed, you don't get ported to a jail. Instead, you get a debuff where you are basically anchored for 3 days (you have to be on for the entire 3 days for it to wear off).