In studies of classroom discourse in early childhood education and care (ECEC), a dominance of the communicative pattern of initiation, response, follow-up (IRF) is shown, and a need of knowledge about extensive dialogue for meaning making is argued. In the present study, communication between children and teacher(s) in play is consider as a form educational discourse mediating language learning. The study, informed by a sociocultural perspective aims to contribute to the knowledge of pattern of establishing a pedagogical dialogue in play activities. What characterizes the communication establishing a joint play in which children come to participate in extensive dialogues is clarified through reanalyzing video-documented data from a project concerning play, learning and teaching in ECEC. The analysis implies a pattern of ICE: children initiating a play (I)--a teacher challenging the initiative (C)--children expanding the content (E). The function of challenging is understood as the critical contribution for opening for and expanding the children's verbal participation. A conclusion of changing the follow-up from evaluating to expanding in a pedagogical dialogue is recommended to study further in different contexts.