This study developed a set of Role-playing game (RPG), which was used to explore whether significant differences exist in academic performance and learning attitudes between RPG-based assessment and traditional lectures. This study also investigated the satisfaction of students toward the RPG scenario. Research participants included 100 second grade elementary students. The experimental results showed the different teaching methods affected the academic performance and learning attitude of second grade elementary students in fraction concepts. Learning by using RPG-based assessment can effectively improve the academic performance and learning attitudes of students. Students with high learning achievement were most satisfied with the RPG-based assessment scenarios, whereas those with low learning achievement demonstrated low levels of satisfaction. It is hoped that the innovative learning method provided by this study will help students.