I've seen a few people use this sort of potion before, though I don't think I'd want to use it myself. Basically, you drink down the potion, and inevitably swallow one of the twenty-sided dice contained within. After nearly choking to death, you cough it up, watch it roll and come to a stop. The number that comes up will influence your luck until the next sunrise.
Should you roll a 10 or higher, congratulations are in order! Depending on how high the roll, you may find a gold piece laying around, or perhaps you'll win big at cards.
Rolling a 20 is something very special. Do this, and your life will be changed forever - perhaps you'll inherit a fortune from a long lost ancestor, or catch a noble's fancy.
Now, if you roll a 9 or lower, then your luck will take a turn for the worse. From a 7 or greater, beware of furniture or doorframes, as stubbed toes are common. Lower still, and you might take ill. Roll a 1, and you might make an enemy of someone with real power.
Now you're thinking - if it's got 20 sides, then there's no 0, right? Unfortunately not. It's widely considered rolling a 0, if you never manage to cough it up at all.
This one is particularly annoying. A bottle that will never break, but always spills.
Hit it as hard as you want, and it will only crack or scratch the surface of the glass. Cork it tight, however, and you'll still end up with the contents all over your pants.
Orc still thinks I can't control my bladder...