Video games are pervasive in today's culture, and the time kids spend playing them may seem, from a teacher's perspective, as time that is lost to education. Sometimes, sadly, this is true. But many good video games, although not explicitly educational in focus, provide powerful experiences that are rich fodder for subsequent instruction. Looking at game play this way--as a source of rich prior experiences that can be brought to bear to illuminate curricular concepts--frees teachers to explore the potential benefits of having a classroom full of gamers.