A common method to judge the capabilities of different characters is to assign each one to a character class in role-playing games. Several abilities and aptitudes are aggregated in a character class which may specifically explain the detailed aspects of background and social standing or enforce behavior restrictions. Classes may be regarded as representatives for archetypes or specific careers. RPG systems that use character classes often are subdivided into levels of accomplishment, to be acquired by players during the course of the game. It is much often for a character staying in the same level in lifetime, although characters are allowed to change class or attain multiple classes in some games. Some systems do not apply classes and levels at all while others combine them with skill-based systems or emulate them with character templates.