Misinformation affects various aspects of people's lives, such as politics, entertainment, and social interactions. However, effective intervention measures to combat misinformation are lacking. The inoculation theory has become a prevalent measure of misinformation. This study employed inoculation theory and developed an interactive game to help the public counter misinformation. In this game, players take on the role of the misinformation spreader, intending to add more followers to their virtual accounts using different strategies. A total of 180 Chinese participants were randomly assigned to game-based inoculation, graphic-based inoculation, and control groups. The results indicated that both types of inoculation interventions significantly decreased the perceived credibility and sharing intention of misinformation. Game-based inoculation was more effective than graphic-based inoculation in terms of misinformation perceived credibility, and the intervention effects were stable after 2 weeks. The graphic-based inoculation contained the sleeper effect, which interventions required a period of time to take effect. Neither inoculation produced countereffects on perceived credibility and nor sharing intention of accurate information.