At the beginning of the twentieth century, a seminar system was introduced at the Faculty of Law. This addition to lectures, until then the only form of instruction, marked a significant shift for future studies. One aspect of the faculty that remained unchanged, by contrast, was the legal regulation of the teaching staff. The first six decades of the twentieth century present a striking contrast to the tumultuous developments of the 1800s.  

The Basel authorities considered establishing a legal seminar as early as 1877. But since most advanced students still left Basel to attend seminars at universities abroad, the idea was soon abandoned. It resurfaced at the beginning of the twentieth century and was implemented in 1907. The seminar opened in the summer of that year at 8 Augustinergasse, primarily with the aim of addressing practical questions through more interactive teaching formats. This met a general need, and in the first quarter of the century, it became an established practice not only among jurists but also in most other disciplines to offer participatory events alongside lectures.

Stabilization of the teaching faculty
Three years before the seminar opened, the most recent University Act of 1866 had been amended to add a chair for Swiss private law to the existing professorships. The demand for such a chair had been voiced at the end of the nineteenth century, following the legal expansion of the faculty in 1891, which had superseded the chair for national law. The five statutory chairs, as established in 1904, covered the following areas: Roman law, Germanic law, Swiss private law, public law, and criminal law. 

The chair for Germanic Law was converted into one for legal history and private law in 1933; otherwise, the faculty composition of 1904 remained legally unchanged until recent times. Nonetheless, development continued on a nonlegal level. The University Act of 1937 introduced flexibility in the number of chairs by authorizing the Governing Council to establish additional professorships that were not subordinate to the existing statutory chairs. One significant institutional innovation in 1938 was the integration of an Institute for International Law and International Relations, though it never achieved the status of a university institute. Faculty staff and institute structures otherwise developed without major changes until the 1960s. 

Expansion since the 1960s
The act adopted in 1937 enabled a doubling of professorships from five to ten between the 1960s and the legal reorganization of the university in 1995. This period also saw the awarding of personal chairs, a provision also envisaged in the 1937 act, along with honorary lectureships and extraordinary (associate) professorships. The expansion of the teaching faculty was necessitated by a rapid increase in student numbers. At the beginning of the 1960s, around 200 students were enrolled in the faculty, a fifth of whom were women. The scarcity of professorships considering subsequent growth and increasing disciplinary specialization is evidenced by the fact that some chairs were given to honorary faculty who had not yet completed a habilitation, while instructors lacking a proper venia docendi were engaged for teaching. In the mid-1960s, assistant positions were also established to support professors in teaching and administration.

A significant milestone for the faculty, which had taken on a more complex personnel structure, was the move to 51/53 Maiengasse in 1983. Initially a stopgap solution after plans for a joint building with the Faculty of Business and Economics at the Rosshof site fell through, the new location offered significant advantages over the old site at 6/7 Münsterplatz, where only the institute director had an office. For the first time, all members of the faculty, from first-year students to professors, were housed under one roof, fostering the development of faculty life.

Educational reforms
The faculty transformation in the 1960s occurred not only at the personnel level but also in terms of how its studies were structured. In 1960, the Faculty of Law finally introduced the licentiate – the last in Switzerland to do so – which replaced the doctorate as the initial degree. This change significantly raised the requirements for a doctorate and greatly improved the quality of many dissertations.

In terms of content, the licentiate system led to an increasing marginalization of legal history. Roman law, in particular, which had been the centerpiece of jurisprudence in the nineteenth century, became significantly less important. Although legal history never disappeared entirely from the curriculum, unlike the Latin requirement which was abolished in 1991, it was taught in an increasingly abbreviated form. 

Legal history was also impacted by the second major educational reform to affect the university and the faculty. When the Bologna system was introduced in 2004/2005, all mandatory subjects were included in the bachelor's degree program, making reductions unavoidable.