Assuming you mean MCMMO. MCMMO is like skills for each type of weapon and more. There are skills like axe levels, and sword levels and more. When you start off, you start with level 0 for each skill. You can level up your axes, swords and other weapons by usually killing mobs. At the start it will be easy to get levels. But after some time it will begin to get hard. The higher your mcmmo level gets for whatever you are trying to level up, the more damage it does. You can also use an ability with it.