Research by Xudong Liang*, Hongbo Fu* and Alfred Crosby* entitled "Phase-transforming metamaterial with magnetic interactions" was recently published in PNAS. Material phase transitions offer promise for driving motion and managing high-rate energy transfer events; however, engineering conventional phase transitions at a molecular or atomic level is challenging. We overcome this challenge by coupling multiple interacting fields within a metamaterial framework. Specifically, we embed magnetic domains, with nonlinear, orientationally dependent force interactions, within elastic structures to control reversible phase transitions and program high–strain-rate deformation. The resulting high-rate energy transformations are used to enhance elastic recoil, which could be used to drive high-power motion and to quickly dampen impact loading events. The developed Landau free energy–based model for this material system broadens the impact of this advance, setting the stage for metamaterials with wide-ranging compositions, interacting fields, and engineered properties.