“Ethics training is an instrument of HRD [human resource development] that includes all educational and developmental methods aimed to implement and promote ethical behavior within organizations (Kreismann & Talaulicar, 2021, p. 11).” Thus, such training in a business context should not only support ethical behavior in the workplace, but also prevent corporate scandals by strengthening ethical competences (Kreismann & Talaulicar, 2021; Schwartz, 2017; Thomas et al., 2004). Additionally, the use of e-based training to strengthen flexible and location-independent access is increasingly of interest as an HRD measure (Li, 2013), though the current state of research in the included empirical literature review shows that it has been the subject of few studies to date. Therefore, e-based business ethics training is examined in this investigation. This study applied a laboratory experimental design to investigate the efficacy of different approaches to designing ethics training – with active, interactive, and passive designs derived from the theoretical foundations in the field of constructivist learning. The theory of the development of moral competence and its measurement is based on the well-established ideas of Kohlberg (1969) and Lind (2016a). Following random assignment to groups of 200 students, the treatment groups (n=50 each) received active, interactive, or passive ethics training, while the control group (n= 50) received none. The four groups were tested for both their moral competence, using Lind’s moral competence test (MCT), and their subjectively perceived learning effects and reaction to training, using a self-report questionnaire. Statistical analyses found no significant differences between the four groups in moral competence after the treatment, but the participants’ self-reports of the active and interactive treatment showed the most positive feedback for self-perceived learning effects and enjoyment of the program. The results of the self-report also reveal that, regardless of the design, all ethical treatments seem to provide a stimulus that sensitizes participants to reflect on ethically relevant problems and to consider a change of perspective and an in-depth examination of various arguments to justify decisions in an ethically challenging business situation.