A game mod describes a modification within an existing commercial computer-based game that has been created by a user. By game modding, a user can participate in the creative process by taking the setting of their favorite game and customizing it for entertainment purposes or to convey information. For years, commercial computer-based game developers committed considerable resources towards preventing users from “hacking” into or “hijacking” their games. Now several computer-based game developers provide editors with their products to encourage users to create content, and to allow educators, for instance, to take advantage of the benefits and production quality of commercial computer games to create customized instruction. This paper focuses on mainstream, accessible games with straightforward modding tools that can be easily integrated into a learning environment.