In recent years, numerous psychological interventions have been developed to reduce susceptibility to misinformation. Inoculation theory has become an increasingly common framework for reducing susceptibility to both individual examples of misinformation (issue-based inoculation) and to the techniques and strategies that are commonly used to mislead or misinform people (technique-based inoculation). In this study, we address two open questions related to technique-based inoculation in two separate experiments (total n = 2188; convenience sample recruited via the Bad News online game platform): (i) can technique-based inoculation effectively reduce susceptibility to real-world misinformation that went viral on social media? and (ii) can technique-based inoculation confer cross-protection against misinformation that does not make use of any of the techniques against which people were inoculated? We find that playing a 15 min game confers psychological resistance against real-world misinformation that makes use of manipulation techniques against which people were inoculated (Cohen's d = 0.37, Cohen's U 3 = 64.4%, p < 0.001), and that cross-protection is achieved but at a reduced effect size (d = 0.10, U 3 = 54.0%, p = 0.001).