Play is the primary way for children to acquire cognitive, social and relational skills. However, children with disabilities risk to be deprived of their freedom and their right to play in spite of the efforts made by adults in the familiar, educational and rehabilitation context. This work investigates the adults' role in letting children with Cerebral Palsy acquiring play skills through a playful interaction with a robot. The originality of this research lies in evaluating the prompt fading technique in a playful environment given that this strategy has so far, in fact, only been applied to contexts of rehabilitation and learning.