All humans were divided into four castes: priests, warriors, traders and laborers. Social contact was limited except for within a person's assigned caste. There were also outcasts or Sudra people who were considered so impure they were barely human. The castes determined a person's rights as well as their rank, with priests being the highest ranking, followed by warriors, then traders, and lastly the laborers. (Not counting outcasts who were the lowest of the low.)