mcMMO isnt iconomy? mcMMO is an RPG like system where u can level up your mining, woodcutting, sword, etc skills. The more you mine the higher your level is. The higher level it is the better perks you get. Perks can be like 1/1000 chance of getting a double drop. So if you have a high level you can have a high chance of getting 2 diamonds from 1 diamond vein.