Autistic Spectrum Disorder (ASD) is a neurodevelopmental disorder mitigated by social, behavioral and communication impairments. One of the models that try to explain such symptoms is that of neuropsychology, which offers deficits in Executive Functions (EFs), highlighting the component of cognitive flexibility. The cognitive flexibility construct is broad, however it is common to be related to the ability to alternate attentional focus and thinking, and the ability to adapt to changes in the environment. Thus, linking on the basis of symptoms of repetitive and stereotyped behavior in the ASD. Cognitive flexibility also appears to be correlated with Theory of Mind (ToM) and shared attention, too, at a level associated with social functioning. Literature states that FEs can improve with training. There are several intervention models for ASD, among them neuropsychological rehabilitation has been the focus of the study. Neuropsychological rehabilitation is a powerful model to remedy and develop cognitive skills that are impaired in some childhood diagnoses such as ASD. There is a scarcity of tools that work in the field of neuropsychological rehabilitation that meet both the need to develop cognitive flexibility and ecological changes, that is, an instrument that enhances the generalization of learning to situations of daily life. However, in this area there are and a common tool used in child rehabilitation involves playful activity. To meet these needs, the objective of this work is to develop a tool for stimulating cognitive flexibility in children with mild and verbal ASD, between 9 and 12 years old. The tool developed was a Role-Playing Game (RPG). The role-playing game involves a re-enactment of a story, where participants must enact roles, considering the characteristics of their characters. Throughout the game, they are faced with challenges, which are problem situations that they must solve in a shared way. The dynamic game offers a favorable context for this flexible behavior practice and experience and meets the cognitive flexibility construct. For the development of the game, several steps were taken to reach the final model, which was tested in a pilot group for later review and adaptation. The final model underwent an agreement assessment by expert judges who presented a 100 percent result for all items obtained. This result confirmed the hypothesis that the role-playing game, called Fables and Fantasies, estimated cognitive flexibility, fit to be used in the proposed group. The Fables and Fantasies RPG game stimulates cognitive flexibility through cognitive training, offering the opportunity and adequate support for this skill to be tried and practiced, with the integration of metacognitive and instructional. of the tool, and this objective composes the future perspectives.