Despite human lifestyles varying greatly among the different cultural groups, some things remain largely universal, for instance humans commonly determine status based on an individuals heritage and wealth. Skill and cunning can become anyone's fortune, but being of noble blood makes some things more or less certain in life. Human societies are commonly divided by hierarchical order into several castes, from the prestigious leaders to the servants and lawless rabble. Each has its own privileges and obligations. Leaders and persons of good social standing are usually of fine birth. The Isenvor and Odar humans band together in disparate tribes, led by despotic leaders. The tribes seldom cooperate over long periods, but sometimes a common goal or enemy can unite them temporarily. The city humans form the most orderly human societies, often constructing larger power structures, where smaller domains are subjects to a central ruling body which forms a nation or an empire. They have built cities like no other people in the region, and many different races and cultures have immigrated to share their urban lifestyle. Cities may be run by mayors or councils, while feudal lords commonly rule rural domains. The Emerald humans lack a formal central leadership, and each domain is ruled by its own lord, assembly or council. Their strong sense of shared culture often drives them to cooperate against external threats.