This study focuses on a close examination of how children express themselves at ECEC in play situations, which form an integral and large part of a typical day. The main research question has been: How can children's social and emotional expressions be understood through analyses of communication and interaction during free play? A qualitative approach has been deemed suitable for this study, since it can provide insight into children's social interaction and engagement with their peers and with ECEC staff, in their natural, everyday ECEC environment. The study was carried out at eight different ECEC centres and one pre-school at various locations in the Swedish-speaking regions of Finland. At the time of observation, the group sizes at the ECEC centres and the pre-school ranged from about 10 to 20 children, aged 3-6. The analysis showed an overarching category of exclusion in play, and in the article we present examples of how children limit each other during play. This is done through imposing limits in play through favouritism by prioritising certain children above others. The article exemplifies this with detailed analysis of play situations showing children's verbal favouritism as well as clear exclusion of other children. The results highlight the need of discussing the issue more in depth.