During the feudal era, the samurai were crucial in shaping Japanese language and literacy. As one of the few literate classes, they contributed to the development of Kanbun, a system of writing Japanese using Chinese characters. This was significant because much of government and intellectual communication required understanding of Chinese script. Furthermore, the samurai were also responsible for the emergence of indigenous Japanese literary forms, such as the war tale (gunki monogatari), which recorded their military exploits and personal honour, influencing the narrative style and vocabulary of the Japanese language.

The samurai class had a significant impact on the development of Japanese religious practices. Their association with Zen Buddhism introduced a new dimension to Japanese spirituality, emphasising self-discipline, simplicity, and meditation. This association led to the spread of Zen ideals throughout Japanese society, influencing other classes as well. The samurai also supported Shinto practices, which revered ancestors and natural spirits, aligning with their respect for heritage and lineage. They patronised the construction of temples and the performance of religious rituals, thereby intertwining their martial identity with religious expression.

The samurai's economic activities were pivotal in sustaining the Japanese feudal economy. They managed agricultural lands and estates, overseeing the production and taxation of the rice crop, which was the backbone of the economy. Samurai stipends were often paid in rice, linking their economic status directly to agricultural productivity. Furthermore, they participated in and regulated trade, both domestically and sometimes internationally, through their connection with merchant classes. Their role in infrastructure development for military and administrative purposes also contributed to economic growth by improving transportation and communication.

Samurai engagement with politics at the imperial court varied over time but was particularly significant during periods when the military government (the shogunate) held power over the emperor. During these times, samurai could serve as advisors, regents, or even emperors if born into the right lineage. They had a profound influence on court politics, especially in the Kamakura and Muromachi periods, where the shogun and his samurai retainers held real political power, overshadowing the imperial court. This engagement further highlights the complex power dynamics between the imperial throne and the samurai class.

The samurai's influence on the Japanese legal system was profound. As local governors and the military arm of the nobility, they were responsible for maintaining law and order. They implemented and enforced 'buke-shohatto', a code for the military houses, which governed samurai behaviour and duties. The samurai also played a role in the development of 'bushido', which although not a formal legal code, had a strong moral influence on the laws of the period. Their adjudication in legal matters often blended legalistic formalities with the moral expectations of bushido, leading to a legal system that was both practical and ethically influenced by samurai values.