Luck Stat

Literally the (useless imo) vanilla luck stat.

Works like any other vanilla attribute, think max health for example.

Comment from the Dev:

There is a server where I was paid to make the Luck Stat, whenever a player kills a monster, influence the drop rate of Gem Stones. Since I got paid for such a work, I see it unfair to post the example for free.

If you're interested with this solution (that requires premium mythicmobs) you may inquire in a spigot dm.