The gamification of online learning has been a subject of interest lately. This study attempts to explore two things in particular, the effects of gamification on learning and the moderating effects of user characteristics. The results demonstrate that the gamification elements contribute to higher learning outcomes while two user characteristics, agreeableness and pre-training motivation, are important moderators of the links between the gamification elements and learning outcomes. The study findings indicate that a gamified system in consideration of user characteristics is an effective means to improving the efficacy of the e-learning environment.