Ingestible sensors have become smaller and more powerful and allow us to envisage new human-computer interactions and bodily play experiences inside our bodies. Users can swallow ingestible sensors, which facilitate interior body sensing functions that provide data on which play experiences can be built. We call bodily play that uses ingestible sensors as play technologies “ingestible play”, and we have adopted a research-through-design approach to investigate three prototypes. For each prototype, we conducted a field study to understand the player experiences. Based upon these results and practical design experiences, we have developed a design framework for ingestible play. We hope this work can guide future design of ingestible play; inspire the design of play technologies inside the human body to expand the current bodily play design space; and ultimately extend our understanding of how to design for the human body by considering the bodily experience of one’s interior body.