The spread of technological and IT tools in recent decades has contributed to the demand for new methods, approaches, and tools, such as games, in the field of education. In recent years, gamification has gained considerable interest in various areas, including industry, healthcare, business and education. Teachers are often attracted to gamification but sometimes do not know how to implement it. It is therefore necessary to train teachers not only on the theoretical content but also and above all on how to plan didactic activities using innovative educational approaches. The context of this research is the immersive 3-hour workshop on the theme "Gamification and education: innovative approaches to facilitate learning" which involved 54 teachers from all over Italy from primary to secondary school. The workshop was organized as part of the Italian Ministry of Education's national PP&S project, which aims to improve teaching and learning using new methodologies and technologies. After a short theoretical introduction, the teachers were guided through the individual step-by-step creation of a gamification activity. The research questions are: Which are the most frequent characteristics, factors, and elements of gaming employed in the planning of didactic activities by school teachers? What were the most adopted gamification strategies? What were the most common difficulties in designing gamification activities? To answer the research questions, we analyzed teachers' responses to the initial questionnaire before the workshop and to the final questionnaire at the end. We considered also the designed forms filled by teachers in order to understand how they employed the proposed methodology within their educational activity and to detect which were the most common difficulties in designing gamification activities. Through the designed form, we considered how teachers incorporated gamification strategies into their activities, whether they did so in a marginal way or in a structured way. The results show that, even if some strategies were more complex to develop, teachers really appreciated the proposed methodologies and they tried immediately to put them into practice. The study is an opportunity to reflect on the difficulties that teachers may have in designing didactic activities on different topics with a gamified approach, in order to redesign teacher training to overcome them.