The knowledge society has brought many possibilities for open education practices and, simultaneously, deep ethical challenges related to the use, sharing and reuse of digital content. In fact, even at university level, many undergraduate students do not respect the licences of digital resources. As part of the contents of a third-year educational technology course for primary teacher training at the University of the Balearic Islands (Spain), prospective teachers learned about these ethics issues. During the 2015/16 academic year, 125 pre-service teachers from two groups of this course were involved in a gamification experience, using Socrative in real-time in the classroom, in which they had to answer different questions related to digital ethics. Its aim was not only to find out what they knew before working directly with the topic--an initial self-assessment--but also to arouse interest and encourage dynamic participation and interaction. At the end of the course, the participants answered a questionnaire in which they were asked about their perceptions of the use of this kind of educational strategy and their transfer in the future. Data were also collected from the same Socrative quiz and the final exam results related to digital ethics. Overall, the assessment from pre-service teachers was highly positive, as well as the scores of the questions related to digital ethics in the final test, and the conclusions of this study highlight both the importance of using more interactive educational strategies in the classroom and the need for training on digital ethics issues in teacher studies.