ISR faculty, research staff, and students are actively involved in advancing the science and technology embodied in computer games and virtual worlds (CGVW). CGVW generally rely on common core software technologies, though the context of their application in entertainment systems versus enterprise platforms for R&D often determines whether they are labeled as a “computer game” or a “virtual world.” Thus, we adopt the combined label to focus on what is common in the development, use, and evolution of CG and VW. OK, good. But why do CGVW merit scientific study and technology development? Is such study just a clever way to disguise playful fun as serious work? How is work different than play? If CGVW are software-intensive systems, then what kinds of software engineering research problems are associated with the development of CGVW?