The EPITEC2 project proposes the incorporation of three perspectives of enormous educational potential: relevant socio-environmental problems (hereinafter, RSPs), the ecosocial approach, and controversial issues ^[1][3]. Heritage education (hereinafter referred to as HE) is a key element of comprehensive training, from the earliest stages of education to the training of the teachers themselves ^[2][3][4][4,5,6], based on the so-called controversial heritage. In this sense, HE promotes the development of critical thinking and the related reflection processes for the formation of a democratic, participatory, transformative, and just eco-citizenship ^[5][7]. To this end, models of future teacher education that are based on the realist perspective and school-based research are successfully employed, with educators seeking to ensure the integration of personal experiences in classroom practice alongside purely theoretical knowledge ^[6][8]. This realistic model and the didactic tools and strategies that are brought into play contribute to the reconstruction of previous experiences and beliefs that could lead to a negative professional identity ^[7][9]. This is a fundamental aspect of initial teacher training since, in many cases, after having completed their initial university training, new teachers enter the profession and reproduce the same models that they experienced during their pre-university training ^[8][10]. It is, therefore, necessary to continue researching didactic instruments and strategies that favor the joint construction and reconstruction of knowledge in all phases of initial teacher training ^[9][11].

HE is configured as the ideal framework for addressing the relevant socio-environmental issues of our society ^[10][12]; to this end, it is essential that teachers know how to develop proposals in the classroom that promote critical thinking in their students, based on innovative and experiential methodologies ^[11][13]. Thus, gamification, understood as the use of game design elements in non-game contexts ^[12][14], may be one of the key ideas that help to improve the working mechanisms of initial teacher training since it makes it possible to bring the course content closer and develop the competencies of university students, especially those related to education ^[13][15].

2. Controversy: Relevant Socio-Environmental Issues and Controversial Heritages

Over the last century, through socially current issues ^[14][16] and critical theory ^[15][17], controversial themes have been introduced into the teaching and learning process in order to overcome the uncritical transmission and reception of memorized and partial content and to promote the reflective and critical spirit of students ^[16][2]. According to Kerr and Huddleston ^[17][18], it is necessary to include these controversial issues in the classroom because of their importance in society, the debate that is generated as part of the democratic process, student participation in the context of receiving and sharing information, the continuous emergence of new controversies, the analysis of controversy by putting critical and analytical thinking skills into practice, the inclusion of highly relevant current issues, or because of the introduction of controversial topics in the classroom by students, among other causes. These same authors state that controversial topics that can be introduced in the classroom can be classified into established topics and very recent subjects, according to their temporality, which will condition the relevance that teachers and students attribute to these themes. Similarly, Stradling ^[18][19] distinguishes between those issues that can be resolved by evidence, the controversy of which is therefore superficial, and those where the dispute is inherently disputed, i.e., issues arising from disagreements based on matters of fundamental belief or value judgments. At this point, we can also differentiate between controversial issues according to the context they affect, so that we distinguish between local and global issues. The opportunity we find here lies in the fact that the teaching of these heritage perspectives allows us to work on these controversial issues from an eco-social approach, in order to form a citizenry committed to advocating and participating in the management, conservation, and safeguarding of heritage ^[19][20][21,22]. In this way, it will be possible to achieve an HE that enables the acquisition of a greater commitment to their community, understanding, and reflection on the possible consequences of the acts that have occurred between past, present, and future connections, in order to understand and value them from a critical and constructive perspective ^[21][22][23,24]. Heritage is, therefore, an educational resource that awakens students’ motivation, makes school content useful for the socio-environmental transformation of their environment, and promotes meaningful or deep learning ^[23][25]. In this way, RSPs and controversial heritage appear as suitable elements for work in initial teacher training, as teaching content, or as resources for the development of future teachers, building an eco-citizenship that seeks social transformation ^[24][20].

3. Gamification: Innovative Methodologies in Initial Teacher Training

In line with the formation of an active and reflective citizenry committed to change and social justice ^[25][26], initial teacher training is a key aspect of ensuring that these education professionals should be suitably trained to carry out the design and experimentation of teaching materials and proposals in this field ^[26][27]. Based on the assumption that controversial heritage serves to address RSPs in the classroom as well as the eco-social education of citizens, and that, in turn, school research on these topics favors the development of critical thinking, we should focus on the conceptions that student teachers in initial training already have of teaching processes ^[10][12]. The aim is to clarify whether future teachers have the necessary skills to be able to act regarding these issues and, therefore, whether they need training in the appropriate handling of controversial issues to encourage the development of critical thinking ^[1][3]. In education, new techniques related to gamification are increasingly being implemented because they exhibit particularly interesting benefits for both students and teachers ^[27][28][29][28,29,30]. In gamified activities, relationships are established between the environment, the players, and each other as they express their emotions, gain experiences, have fun, relax, and find solutions to problems ^[30][31]. Moreover, learners show positive attitudes towards the gamification of content, as it encourages student motivation and, in general, helps them to receive positive feedback during the teaching process ^[31][32]. It can be affirmed that gamified activities help to improve communication skills and also coordination and collaboration between peers, improving the inclusion in the classroom of all participants in the game. In addition, they promote a positive attitude in students regarding the achievement of academic success ^[30][31]. According to a study by Perrota et al. ^[32][33], the use of gamification in the classroom appears to improve learning outcomes and increase student engagement with educational processes. Active and gamified methodologies of this kind generate a high level of motivation in university students, allow cooperative work, and favor the acquisition of key competencies and subject contents ^[33][34]. Based on the scientific literature, rwesearchers find several precedents on gamification in initial teacher education ^{[34][35][36][37][38]}[35,36,37,38,39], although it is only on rare occasions in these precedents that any gamified activity is used to work on current controversial topics, such as in the studies by Clarke et al. ^[39][40] or Nicholson ^[27][28]. However, pre-service and in-service teachers still show a high level of ignorance about the educational use of gamified strategies ^[40][41][41,42]. In addition, no previous work linking controversial issues, gamification, and heritage in initial teacher education was found. This means that teachers do not find adequate references to unify the potential of gamification with the benefits of controversy-based HE, thus hindering the dissemination and use of these types of strategies in the classroom to address current RSPs. It is, therefore, essential to ensure that future teachers are trained in strategies that favor a holistic perspective when dealing with knowledge, beliefs, and feelings that facilitate the beginning of the construction of critical thinking and increase motivation, inclusion, and group cohesion, and that are considered to be optimal alternative methodological strategies that place students at the center of their own learning in an active and cooperative way ^[27][28][28,29]. One example of a gamified activity is role-playing games, which consist of a collective game composed of a storyteller and participants who adopt roles and create or recreate stories ^[42][43]. The role-playing game allows an empathic knowledge of reality, while its structure entails a certain amount of group work, enabling interaction between equals, and involving creative situations that students interpret as a means of knowledge acquisition ^[8][10]. Roda ^[43][44] distinguishes between four modalities of role-playing (live role-play, written role-play, table role-play, and role-playing video games) with which to combine multiple options for implementing this strategy in the classroom. Role-playing games represent an innovative didactic proposal in the teaching of social sciences, offering multiple educational advantages when addressing relevant problems, helping students to develop informed opinions, stimulate critical thinking, develop social and argumentation skills, and emphasize the procedural and attitudinal aspects ^[41][42]. The following strategies share similarities with each other, mainly in that they are both fun, motivating, and exciting elements, where respect and collaboration are maintained while developing communication skills and critical thinking ^[44][45], and they can both be applied relatively easily in class. Firstly, the ‘Escape Room’ is a game in which a group of people has to collaborate actively in the resolution of different enigmas and problems to achieve the aim of getting out of a room ^[30][45][46][31,46,47]. Conversely, ‘Breakout’ consists of opening a closed box with different types of locks; it is necessary to solve problems to find the codes that open them ^[47][48]. Several experts, such as Nicholson ^[27][28] or Veldkamp et al. ^[29][30], are introducing these strategies because they offer great benefits that are of interest to both students and teachers. According to García-Lázaro ^[28][29], the peculiarity of Escape Rooms is that they are a resource that demands the inclusion of a great variety of personalities in the players. In turn, Moreno-Fuentes ^[33][34] stated that Breakout is an experience that is more closely related to educational action. Another example of gamified activity is ‘Civil Dialog’, a structured, simulated debating technique for controversial issues, in which participants are asked to take sides by sitting in chairs arranged in a semicircle and presenting their ideas, which range from ‘Strongly agree’ to ‘Strongly disagree’ ^[48][49]. The format was created in 2004 as a way to explore citizens’ reactions to political rhetoric. It was developed at the Hugh Downs School of Human Communication at Arizona State University and has continued to be developed by John Genette, Jennifer Linde, and Clark Olson, among other academics. This technique provides a venue for civilized and facilitated citizen dialogs on the issues of our time ^[49][50]. A Civil Dialog round is composed of a moderator (teacher), the audience (student body), and 5 participants from that audience and usually lasts between 30 and 45 min. This activity is less well known, but it represents a great tool with enormous potential for working on social problems of current relevance and fosters positive values, such as empathy and respect, by being able to place each student in positions contrary to their own if combined with roleplay, as can be seen in the study by Cruz-Lorite et al. ^[38][39]. Based on the experiences found, the range of gamified activities that can be used in classrooms is very wide. Using these prior studies as a starting point, we can establish a classification of those gamified activities that may be most useful for the teaching of controversial heritage, based on the following features:

• Static role-playing games: this includes written role-playing games, board games, and similar games.
• Videogames: all games that need some kind of technological support in order to be played (mobile, tablet, computer, console, etc.).
• Breakouts: enigmas, puzzles, and brainteasers that can be solved without leaving the classroom.
• Escape Rooms: enigmas, puzzles, and brain teasers that need to be solved to move from one space to another.
• Historical re-enactments: activity in which participants recreate some aspects of a historical event or period. This may be narrowly defined, such as a war or other specific event, or have broader coverage.
• Live role-play: a first-person game in which the representation of the characters by the players takes place in real time and in a staged manner.
• Civil Dialogs: simulation of debate on current conflicts, adding the use of role-playing to assign divergent positions.