The research aimed to know the result of validity, practicality, and effectiveness of products from the development of games-based learning media in terms of students' mathematical reasoning in three-dimensional shapes. The type of research and development referred to ADDIE model which included five stages, namely analysis, design, development, implementation, and evaluation. The subjects of the research were the 25 VIII grades junior high school students in one of the junior high schools in Indonesia. The research instruments used were the validation questionnaire sheets, teacher responses questionnaire, and student responses questionnaire. The data collection used a Likert scale. Furthermore, the effectiveness data were collected from the post-test that was done by the student through learning media to know their mathematical reasoning abilities. Meanwhile, the data analysis technique used quantitative descriptive analysis. The result showed that media was very valid with an average of 91,86%. Moreover, it was very practical to see from the average of teacher response questionnaire which was 89,58%, and the average of student responses questionnaire which was 85,36%. The value of effectiveness was determined based on students' post-test scores which was 84%. Thus, it can be concluded that this media was effective to be applied as a learning media for junior high school. [For the complete proceedings, see ED655360.]