A study examined differences in cardiovascular (CV) reactions and hostility following non-violent play and violent video game play. Subjects were 30 male college undergraduate students. Only male subjects were used because most video games are male oriented, males frequent videogame arcades more often than females, and the gender gap in video game play widens with age until the undergraduate years. Hostility and CV reactivity were examined after subjects' played either a nonviolent game of billiards or a violent video game. The video game, "Mortal Kombat," was presented in either a less violent (MK1) or a more violent (MK2) version. Results indicated that subjects who played the video game had higher heart rate reactivity than those who played billiards. Subjects who played the MK2 version showed greater systolic blood pressure reactivity than those who played the MK1 version or billiards. Subjects who played MK2 scored higher on the hostility measures than those who played MK1, who in turn scored higher than those who played billiards. The results suggest that the level of video game violence, not just the violence per se, should be of concern to consumers. (HTH)