This research investigates the relationship between mindfulness and digital games, by identifying which aspects of mindfulness can be trained by digital games and which game elements influence factors of mindfulness. Games and interactive approaches with research evidence for their efficacy are presented for each individual mindfulness factor, as defined by the CHIME eight-factor model of mindfulness. Two experiments were conducted to validate whether games can improve mindfulness. First, an expert review was conducted, where domain experts rated the fit of games to their associated mindfulness factor. Second, a laboratory study tested the effect of games on mindfulness, revealing positive significant effects on state mindfulness. Elaborating on the research findings from all studies, a framework is proposed to inform the design of digital games for improving mindfulness, and implications plus limitations are discussed.