Aim/Purpose: The study aimed to investigate the effect of using the gamified flipped classroom instructional method on the students' overall achievement compared to the traditional non-gamified, non-gamified flipped classroom, and traditional gamified instructional methods. Background: Flipped classroom is helpful to address limited class time, implement different pedagogies, and help students better attain their learning outcomes and improve their academic achievement. Motivating and encouraging students to perform or complete flipped learning activities is a challenging issue affecting the success of the flipped classroom. This research posits that gamification presents a promising solution, and adding gamification to the flipped classroom is important for its success. However, little is known about the effects of integrating gamification into flipped learning without sufficient results to generalize. Pedagogical designs with appropriate theoretical foundations should be added to the literature on flipped learning and gamification. This research proposes a learning model that combines gamification within flipped classroom via quizzes online platform with the main flow theory requirements. The purpose of this combination is to motivate and engage learners in flipped classroom activities. Methodology: The data were collected from 101 undergraduate students in a database management course at Al al-Bayt University in Jordan. The students were assigned to four different instructional methods according to their preferences (traditional non-gamified, non-gamified flipped, traditional gamified, and gamified flipped classroom). A study with a quasi-experimental factorial design was carried out using midterm and final exam instruments to assess the students' overall achievement. Two-way factorial ANOVA was employed to examine the main effect of the instructional method, student gender, and the interaction effect on students' overall achievement. Bonferroni's multiple comparisons test was carried out to compare and determine which instructional method had the main effect and achieved the best grades among test groups. Contribution: The current study proposed a gamified flipped learning model guided by the theoretical foundations of flow theory. This study offers a novel contribution to the literature by illustrating the importance of employing gamification in the flipped classroom and how the gamified flipped instructional method affects student achievement, especially when appropriate gamification design and careful game element selection. The effects reported by this study provide empirical evidence and valuable insights for researchers, practitioners, and educators about the issues of gamified flipped classroom and guide instructional designers to apply appropriate game elements. Findings: The findings showed that the gamified flipped group outperformed the other three groups and significantly improved students' overall achievement with a large effect size. Employing gamification within the flipped classroom instructional method improved 23.9% of the total variance in the students' achievement through increasing their motivation to complete flipped classroom activities. It has also been found that the non-gamified flipped group outperformed both the traditional non-gamified and the traditional gamified groups. Students' gender was also not a significant factor regarding male and female achievement in using gamified flipped classroom. Recommendations for Practitioners: This study recommends that instructors who utilize flipped classroom should combine other new technologies within in-class activities, such as gamification, instead of traditional discussion in classroom meetings. Thus, the in-class activities become more attractive, increasing their students' motivation. Recommendation for Researchers: Researchers need to understand the factors enhancing the flipped learning activities and the ways of designing and implementing gamification elements to develop new learning models. Impact on Society: Gamified flipped learning can help students improve their achievement and help instructors perform in-class instructional activities, leading to more effective and efficient higher education. Appropriate design and use of gamification elements within flipped learning can promote and encourage the use of such a model. Future Research: Additional research should be conducted to explore and measure students' motivation, engagement, and in-class collaboration due to the gamified flipped classroom instructional model. Further experimental studies on other courses in different environmental variables are also recommended.