Few studies have compared gamblers who play in exclusively online (i.e., Internet-based), exclusively offline (i.e., land-based), and mixed-mode contexts. In studies that have compared these groups, mixed-mode gamblers have consistently exhibited the greatest susceptibility to problematic gambling. In order to expand the scope of previous research that has compared gamblers based on their preferred mode of play, and to improve understanding of mixed-mode gamblers' proneness to problematic gambling, a sample of gamblers who play in exclusively online, exclusively offline, and mixed-mode contexts were compared on indices of gambling involvement, motives, and personality traits. Results indicated that mixed-mode gamblers played a wider range of games, and reported higher problematic gambling severity scores, higher scores on enhancement and social gambling motive scales, and lower and higher honesty-humility and extraversion personality scores, respectively. Associations between gambling motives and personality traits are discussed in relation to the role that these characteristics might play in mixed-mode gamblers' increased risk of gambling-related harm.