Later, the job responsibilities of Shugo were clarified, and in Goseibai-shikimoku (code of conduct for samurai) that was enacted in 1232, the duties of Shugo were limited to the military and police duties of Taibon-sankajo (enforcing the obligation of the gokenin, an immediate vassal of the shogunate in the Kamakura and Muromachi through Edo periods, to provide security in Kamakura/Kyoto, investigating and apprehending rebels, and investigating and apprehending murderers) and command supervision of Obanyaku (a job to guard Kyoto), and it was forbidden for them to rule Kokugaryo or get involved with government, which was the privilege of the Kokushi.
その後、守護の職務内容が次第に明確化されていき、1232年（貞永1）に制定された御成敗式目において、守護の職掌は、軍事・警察的な職務である大犯三ヶ条の検断（御家人の義務である鎌倉・京都での大番役の催促、謀反人の捜索逮捕、殺害人の捜索逮捕）と大番役の指揮監督に限定され、国司の職権である行政への関与や国衙領の支配を禁じられた。