While more universities are including IT accessibility in their computer science programs for undergraduate and graduate students, there is little accessibility training available for K-12 teachers. We created an intervention through which postsecondary students had opportunities to experience five computer games with a simulated impairment (color-blindness, auditory impairments, physical disabilities, blindness, or low-vision); first they played the game that was inaccessibly designed and then they played a version that was accessibly designed. The activity ended with a discussion of accessible design techniques. We tested the intervention with 18 teachers who were students in a university web development course that was part of their computer science training. Results show that teachers were very receptive to including accessibility topics in their future classrooms and thought the intervention was an effective method for teaching high school, middle school, and elementary school students about accessible design.