The proliferation of misinformation and disinformation threatens to erode the credibility of public institutions and limit their capacity to implement policies that enhance public well-being. While health misinformation represents an urgent global challenge, relatively little research has examined solutions in low- and middle-income countries. This study experimentally tests the impact of a novel WhatsApp chatbot game pre-bunking inoculation intervention in Jordan to boost capacity to identify common misinformation techniques and reduce the likelihood of sharing misleading headlines with others??effectively “inoculating” them against health misinformation. A sample of 2,851 participants was recruited online and randomly assigned to five study arms: (1) comprehensive game-based inoculation, (2) brief game-based inoculation that highlighted examples of only misinformation, (3) infographics-based inoculation, (4) exposure to placebo infographics unrelated to misinformation, and (5) pure control. To evaluate the impact of the intervention, the study assesses two main outcomes: (1) ability to discern accurately headlines using misinformation techniques and headlines that do not use misinformation techniques, and (2) discernment in sharing the two types of headlines. Compared to the placebo group, the comprehensive game significantly improved discernment of misinformation and reduced the likelihood of sharing misleading headlines. These findings suggest that games can effectively inoculate the public against misinformation in the context of a middle-income country in the short term. Future research is needed to explore the boundary conditions of the findings.