Many countries are focused on teaching 21st century skills as a means of being competitive in the world economy by improving educational quality. My own work at CRESST is focused on 21st century skills, but from an assessment perspective. Although such skills are embedded in content and assessed using various techniques, we believe it is important to generate two scores from each assessment, a score for content (e.g., math) and a score for various 21st century skills (e.g., problem solving, decision making). We need a specific score for each 21st century skill as one would teach problem solving differently than decision making. A single math score would not permit such adaptation. Further, to benefit from these assessments, reliable and valid measures of 21st century skills should be incorporated into games and simulations that teach and assess 21st century skills. I will report progress on our research on this topic.