Transforming the bulk soft elastomer to the even softer architected 3D structures further enhances the ability to protect the soft brain-like gel from impact. For instance, the magnitude of peak deceleration is reduced from 52.9±7.6 g (bulk S0.5) to 41.4±3.9 g for the structure with 35.3% relative density (Figure ,ii). The mHIC is reduced to (35±10)%. Further decreasing the relative density to 29.0% also decreases the magnitude of peak deceleration to 35.2±3.6 g and decreases the mHIC to (25±11)%. For the 3D structure with the lowest relative density of 19.5% and the lowest apparent modulus of 5.2 kPa, the magnitude of peak deceleration increases to 43.5±5.9 g and the mHIC increases to (59±24)% (Figure ). The increase in peak deceleration is likely because the softest structure deforms too easily and does not dissipate sufficient energy during the impact, resulting in more energy being transferred to the brain-like gel than the stiffer structures.