Sport participation is normally ingrained by competitiveness. Unsurprisingly, sport communities for children and youth most often have a dominating focus on promoting abilities and performance. Unfortunately, such a focus is linked to reduced sport participation. Thus, clubs and organizations who are successful in developing mass participation may have found novel ways to organize how their members participate in a community and sport as a game. This quintain multi-case study combine James Carse’s finite ‘game theory’ and Wenger’s ‘communities of practice’, to understand what characterizes sport participation among members in the handball community called “Happy League”. The community has within few years attracted more than a thousand children with a highly diverse range of age, gender, diagnosis and disabilities across approximately 82 club teams in Denmark, Faroe Island and Greenland. The data collection included participant observation of training and competitions in two clubs over a four-month period, combined with 25 interviews with parents across 10 clubs. Through a ‘theoretical’ thematic analysis in which codes and themes were generated deductively-inductively, the following over-arching themes were developed; Don’t Worry, Be Happy (i.e., joint enterprise), The Universe of Happy League (i.e., shared repertoire), Coopetition across clubs (i.e., mutual engagement), and We do not have rules, we have boundaries (i.e., Infinite game). The results may broaden our conventional notions in sport participation as the portrayed transformed sport participation within Happy League have the potential to inspire practitioners and researchers to emphasize a more inclusive and socially oriented practice in youth sport.