Devin Krauter sits on the end of his bed, tapping buttons on his video game controller to shoot down alien beasts while chatting with other players through a headset, texting on his cell phone and talking to a visitor. The 17-year-old high school junior is ranked by a video game Web site among the best players at “Gears of War 2,” in which soldiers attack the enemy with an assault rifle that has a mounted chain saw bayonet. He says the game teaches him to think on his feet — and that he thinks about succeeding, not slaying.
