2.2.1. Experimental Group

Assisted by their teacher, students chose the monuments to be modeled and then used the Thingiverse website for 3D modeling (Figure 3). All tokens were printed in a 3D printer.

**Figure 3.** Thingiverse [46] interface to choose and download 3D models.

Following that, students were given a written test, consisting of 5 exercises aligned with the subject's (European geography) learning goals, as stated in the curriculum. Students were divided into 4 teams and played Geopoly four times. Each game lasted 40 min. In the end, for five minutes all players were discussing the game session, reflecting their strategy.

After this initial educational intervention, students were presented with a post-test assessment and filled out an Intrinsic Motivation Inventory/IMI questionnaire; IMI is a multidimensional measurement device used to assess the subjective experience of participants with respect to a specific activity, providing insight to intrinsic motivation and self-regulation [47] and has been tested for validity using CFA [48] and reliability [49]. Finally, students evaluated the game by answering a questionnaire; this process is summarized in Figure 4.

**Figure 4.** Experimental group's process.
