This study examines the effect of a gamified information security education system (ISES) on developing users' information security awareness and protection behavioral intention. We developed a research model based on affordance theory and means-end chain theory. Using a scenario-based experimental survey approach, we obtained 220 valid samples and then conducted partial-least-squares structural equation modeling (PLS-SEM) to test the model. The results showed that (1) the affordance of the gamified ISES can enhance users' information security awareness through both emotional and cognitive paths; (2) information security awareness positively influences information security protection behavioral intention, but physical presence and information security knowledge growth do not; and (3) interest-type curiosity positively moderates the relationship between enjoyment affordance and physical presence, and deprivation-type curiosity positively moderates the relationship between knowledge affordance and information security knowledge growth. This study identifies the emotional and cognitive stimulation paths of the gamified ISES to enhance users' information security awareness and protection behavior intention and reveals the moderating role of curiosity, which enriches the empirical research on the impact mechanism of the gamified education system in the field of information security. In addition, our research can provide practical and feasible suggestions for education departments and design units to reasonably apply and design gamified ISESs. The influence of education level and other factors on information security protection behavioral intention can be further explored in future research.