A study published in Additive Manufacturing, a leading journal in the field, proposes an atomic faulting mechanism that simultaneously achieves high strength and ductility in Ni-rich medium-entropy superalloys, offering a new pathway for multi-principal element alloys to overcome the strength-ductility trade-off. Ni-rich medium-entropy superalloys belong to the multi-principal element alloy system, where stacking fault energy is tuned through compositional design, enabling plastic deformation to be accommodated synergistically by mechanisms such as stacking faults and twinning. Compared to conventional Ni-based superalloys, this system is expected to achieve higher ductility while maintaining high-temperature strength. Published in an additive manufacturing journal, this research provides material and process design directions for obtaining fine microstructures under rapid solidification conditions in metal additive manufacturing (e.g., laser powder bed fusion), thereby triggering stacking-fault-dominated deformation mechanisms. Value for powder buyers: ① Ni-based/Ni-rich superalloys are core materials for hot-end components of aero engines and gas turbines, with long-term rigid demand for additive manufacturing powders; ② if the stacking fault mechanism is engineered, it will create new grades of Ni-rich medium-entropy superalloy powders and associated process windows; ③ it is recommended to track the composition-process-microstructure-property data of this alloy system as a basis for benchmarking and differentiated development of high-end Ni-based powder grades.