Choosing a career is one of the most important decisions that youth has to take but many young people find this a hard issue to engage with. Current career counselling practice does not appear very compelling or motivating to young people. Professional games could provide a more engaging and motivating way of acquiring professional awareness and competence for career decision making and learning. We present the design and effects of playing a game that aims to increase career awareness and adaptabilities in youth (13-19 years). In a Randomized Controlled Trial, 93 high school students from Iceland and Romania were asked to carry out career-oriented activities, with half playing an interactive game and the other half performing a paper-and-pencil version of the same activities. The students were compared on career adaptability, career learning and career awareness scores before and after these interventions. Main results show that engaging players in these career-oriented activities has short term effects on outcome scores for career adaptabilities and for perceptions of career learning competences. Students who played the game report significantly faster growth on career adaptabilities that deal with "concern", "control" and "confidence". It can therefore be concluded that introducing game-based learning in career decision support for youth is a promising endeavour.