Is the plague on purple items random?

[John_Louie_Gonzales]

Just a simple question here, Is plague on enchanting items to purple really random? Is just that It kinda relates itself to the effects that you get on the item. It feels like the better the effects, the worst is the plague. I managed to enchant “Health Effect Increase” + “Equip Load Gain” twice on an armor with the plague “Focus Halved”. The first time I got it I keep it cause its good for my build, but I hate the focus halved to much. So I try to grind again to get the same effects but ended up getting the same plague too. Like wth is that.