The Elders had a number of responsibilities, most clearly delineated in the 1634 ordinance that reorganized the government and created a number of new posts:
The Rōjū served not simultaneously, but in rotation, each serving the Shogun for a month at a time, communicating with the Shogun through a chamberlain, called Soba-yōnin. However, the Rōjū also served as members of the Hyōjōsho council, along with the Ō-Metsuke and representatives of various Bugyō (Commissions or Departments). As part of the Hyōjōsho, the Rōjū sometimes served a role similar to that of a Supreme Court, deciding succession disputes and other such disputed matters of state.
Under the reign of Tokugawa Tsunayoshi (1680-1709), however, the Rōjū lost nearly all their power, as the Shogun began to work more closely with the Tairō, Chamberlains, and others, including Yanagisawa Yoshiyasu, who held the power of a Tairō, but not the title. The Rōjū became little more than messengers, going through the motions of their proper roles as intermediaries between the Shogun and other offices, but not being able to exercise any power to change or decide policy. As Arai Hakuseki, a major Confucian poet and politician of the time wrote, "All the Rōjū did was to pass on his [Yoshiyasu's] instructions" (Sansom 141). Even after Tsunayoshi's death, the Rōjū did not regain their former power. They continued to exist, however, as a government post and a council with, officially if not in fact, all the powers and responsibilities they originally held, through the Edo period.