Background: The Situated Game Teaching Through Set Plays (SGTSP) model, a newly proposed curricular model, extends the previous game-based approaches by adopting the Theory of Situated Learning as a framework to focus on the relational and situational nature of the changing relations of all game parameters in a specific momentary game scenario. However, as a new game-based model, SGTSP warrants further empirical research investigations to establish its effectiveness at advancing student learning such as skill acquisition and game competence. Purpose: To examine the effects of the SGTSP curricular model on secondary school students’ tactical knowledge, technical ability, and game performance in badminton when compared with a technique-focused approach during a 10-lesson unit. Methods: A completely randomized block design with a repeated measure was used to address the research purpose. A sample of 158 sixth graders from eight classes at two Turkish middle schools (67 girls and 89 boys; Mage = 12.62 ± 0.47) were assigned to either the SGTSP (n = 79 from four classes) or the technique-focused approach conditions (n = 79 from four classes) for the experiment. Assessments were conducted before and after the badminton instructional unit. The statistical models consisted of one of the four technical ability performances, components of game performance, or tactical knowledge as a dependent variable and eight independent variables: teacher, treatment, class nested within teacher and treatment, gender, skill levels, and three 2-way interactions between treatment, gender, and skill levels. A series of repeated-measure multivariate analyses of variance were conducted to analyze the data. Results: Participants in both groups improved tactical knowledge, forehand long serve, forehand clear, smash, and drop skills, and game performances from pre to post. Participants in the SGTSP condition showed significantly greater improvements (). Discussion and Conclusion: The findings of this study substantiated the positive effects of the SGTSP model on developing secondary school students’ badminton tactical knowledge, technical ability, and game performances in badminton compared with the traditional technique-focused approach.