An Action Research in Increasing Student Engagement and Achievement in PNU-ITL Grade 9 Science class using Theme-based and Gamified Instructions Monton, Reycelle May Y. | Olor, John Christian A. | Quesada, Aleczandra C. | Volante, Aubrey May B. | Zuño, John Michael G. monton.rmy@pnu.edu.ph | olor.jca@pnu.edu.ph | quesada.alc@pnu.edu.ph | volante.amb@pnu.edu.ph | zuno.jmg@pnu.edu.ph ABSTRACT This study determined and described the effectiveness of themed and gamified activities towards the students’ engagement and achievement. It aims to answer the fundamental question: “Is thematic/gamified instructions an effective teaching strategy in increasing students’ engagement and achievement in science?”. The literature presented offers a strong foundation on the use of gamification and the practice of theme-based teaching approach in learning, however, there are only a few literatures of the same concept that are localized in the country. The research involves 19 Grade 9 PNU-ITL science students who are subjected to two different teaching instructions in an online modality: Nongamified & Non-themed-based instructions and gamified & themed-based instruction, tested through a Google Forms and was analyzed using a sign-test. Results of the data analysis indicated that the calculated p-value (p = 0.0007) is less than the critical value (α = 0.05) thus rejecting the null hypothesis. Therefore, it was concluded that themed and gamified instructions had a significant, positive effect on the increasing of students’ engagement and achievement in science. It was recommended by the study to have the assessment tools be validated and increase the number of respondents. Keywords: Student Engagement, Achievement, Theme-based Approach, Gamification