We present an educational 3D game called Rashi Game, which instructs students via exploration using the inquiry teaching method. We first describe the Rashi Intelligent Tutoring System in its original form, and then describe the details and features of Rashi Game, the 3D game that we have developed. In particular, we argue that inquiry-learning environments are particularly viable for educational 3D games. This is because of the similarities between some common game mechanics and the inquiry-learning paradigm. These include freedom to explore open-ended environments, interaction with environments, and realistic scenarios. We briefly summarizing results that have been obtained via pilot studies of the efficacy of Rashi Game, and remark on what directions future work in educational 3D games might take.