There are four main classes within Mithrym, each includes a set of sub-classes. Fighters include fierce warriors, battle-hardened soldiers, tenacious wardens and rugged labourers. Clerics include zealous Paladins, caring Healers, riteous Priests and fastidious Administrators. Wizards include learnéd Mages, wild Sorcerers, clever Artisans and fiery Politicians. Rogues include deadly Assassins, sly Thieves, cunning Diplomats and keen Hunters.

Mithrym does not include multi-classing however all weapon and non-weapon proficiencies are unviersally available to all classes and sub-classes alike. Each class and sub-class also include their own unique bonuses and abilities.