The examination regulations (only available in German) specify the rules to be complied with when going abroad.
Please find section 10 of the Study and Examination Regulations of the University of Mannheim for the master's program “Master of Laws (LL.M.)” below in a translated version:
(1) 1 Instead of completing the modules specified in section 9 [“Internationale Wahlmodule und Schlüsselqualifikationen” (international elective modules and key competences)], students may spend a semester at a university abroad. 2The courses taken during the period of study abroad shall be similar in content to his or her chosen program of study. 3In the course of the semester abroad students shall obtain 30 ECTS credits. 4If students obtain less than 30 ECTS credits during the semester abroad, they shall acquire the remaining credits by attending courses from the modules specified in section 9.
(2) 1Students shall choose appropriate modules from the module catalog of the receiving institution well before their period of study abroad begins; they shall submit their choices to the examination committee or to an office designated by the committee and have them approved. 2Coursework and examinations completed in the context of the modules that have been approved in accordance with sentence 1 are recognized according to the specifications in section 17 subsection 2 sentence 3.