In this paper, we make a qualitative analysis of didactic experiments performed with five 6 to 10-year-old children and five primary school teachers, starting from a structured game with probabilistic elements. The fundamental idea is to stimulate probabilistic thinking not only by playing a card game with decision making in uncertain situations, but by inventing games modifying the initial game. These experiments are grounded on the importance of emotions for learning, the subjective probability approach, and researches on problem posing. We have found that this activity of inventing games has a significant impact on the development of probabilistic thinking in children and teachers; it reduces the anxiety and it could be used in teaching strategies to foster statistical and probability literacy. Some of its positive effects are the strengthening of creativity, self-efficacy, self-esteem, the ability to ask questions, and the enjoyment of learning.