This AAPT lesson is the linchpin of our High School Digi Kit on energy transfer and transformation. Students play the role of "Energy Actors" to model how energy is transferred across systems and how it converts from one form to another. Inspired by a 2014 article in The Physics Teacher magazine, this activity aims to promote much deeper understanding of the Law of Conservation of Energy: energy moves and changes form, but is never "lost" or "created" out of nothing. As students move around from one defined "system" to another, they use hand-held signs to denote changing energy forms. Every learner will be actively engaged in modeling and tracking the energy flow. The digital resources in this Kit support teachers in integrating math, graphing energy change, introducing design projects, and further modeling energy interactions with digital simulations. Expect lively discussions and productive group collaborations!