Peer pressure can influence risk-taking behavior and it is particularly felt during adolescence. With artificial intelligence (AI) increasingly present in a range of everyday human contexts, including virtual environments, it is important to examine whether AI can have an impact on human’s decision making processes and behavior. By using the balloon analogue risk task (BART) evaluating propensity to take risk, in this study 113 adolescents' risk-taking behavior was measured when playing alone and in the presence of either a robot avatar or human avatar. In the avatar conditions, participants performed the BART while the avatars either (1) verbally incited risk-taking or (2) discouraged risk-taking (experimental tasks). Risk-taking behavior in the BART was assessed in terms of total number of pumps, gain and explosions. Tendency to impulsivity was also evaluated, as well as the effects of age and gender on risky behavior. The main finding showed a significant effect of both avatars on risk-taking tendency, with riskier behavior during incitement than discouragement conditions, the latter being also substantially different from the playing-alone condition. The results of this study open up new questions in a very sensitive and timely topic and offer various insights into the effect of nudging on adolescents’ behavior in virtual contexts.