Gamification, an application of game design elements to non-gaming contexts, is proposed as a way to add engagement in technology-mediated training programs. Yet there is hardly any information on how to adapt game design elements to improve learning outcomes and promote learner engagement. To address this issue, we focus on a popular game design element, competition, and specifically examine the effects of different competitive structures, i.e., whether a person faces a higher-skilled, lower-skilled or equally-skilled competitor, on learning and engagement. We study a gamified training design for databases, where trainees play a trivia-based mini-game with a competitor after each e-training module. Trainees who faced a lower-skilled competitor reported higher self-efficacy beliefs and better learning outcomes, supporting the effect of peer appraisal, a less examined aspect of social cognitive theory. Yet trainees who faced equally-skilled competitors reported higher levels of engagement, supporting the balance principle of flow theory. Our study findings indicate that no one competitive structure can simultaneously address learning and engagement outcomes. The choice of competitive structures depends on the priority of the outcomes in training. Our findings provide one explanation for the mixed findings on the effect of competitive gamification designs in technology mediated training.