Play-Testing and Requirements Engineering: Implications for Research and Teaching In Requirements Engineering (RE) for large scale game systems, play-testing is an important activity that is used to validate requirements from players’ perspective. Play-testers are not professionals that are involved in the process of RE. They are not professional testers, either. Yet, their feedback in terms of perceptions and experiences of the early prototypes of a game, have a decisive impact on what the RE-professionals do next in the RE process. This position paper presents a qualitative study that sought to discover who takes the role of play-testers and what kind of feedback play-testers generate in the early stages of RE for games. The case study responds to the observation that no textbook on RE or software engineering addresses play-testing as a phenomenon, and that classic Computer Science programs at universities teach testing techniques mostly in the context of embedded systems, hence students often are left with little opportunity to develop testing skills that build upon play-testing practices happening in the game development sector. The study therefore was aimed at identifying important implications that play-testing may have for research and teaching.