Education has seen an increase in interest in utilizing gamification to improve student engagement and motivation. This quasi-experimental study investigated how gamification affected the instructional competence and engagement of English Language Teaching (ELT) teacher trainees during micro-teaching. Forty pre-service ELT teachers were randomly assigned to either an experimental gamified micro-teaching group or a control non-gamified micro-teaching group. The gamified micro-teaching utilized missions, real-time feedback badges, peer ranking/leaderboards, and digital points (all gamified components) as part of the micro-teaching process. The researcher collected pre- and post-intervention data using the ELT Instructional Competence Rubric (ELT-ICR), Student Engagement in Teacher Training Scale (SETTS), and semi-structured interviews. There were significant differences in instructional competence across all three ELT-ICR and SETTS identified areas between the experimental and control groups after participating in their respective interventions. While teaching simulations, participants in the gamified micro-teaching group reported a substantially greater amount of motivation and lower amounts of anxiety. Qualitative analysis of data indicated that members of the experimental group participated in more collaboration, self-reflection, and willingness to take instructional risks. Overall, the researchers concluded that strategically designed gamified micro-teaching can significantly improve pre-service ELT teacher trainees’ pedagogical competence and affective engagement. Recommendations arising from the results of this study include incorporating gamification constructs that identify experiential learning and self-determination theory into teacher training curricula.