The study explores the harnessing of premature necking in multi-principal element alloys (MPEAs) to achieve superior strength and ductility. Specifically, it focuses on the VCoNi alloy, which contains local-chemical-order (LCO) regions as built-in heterogeneities. The research demonstrates that Lüders banding, an initial tensile response, induces localized necking at the band front, creating triaxial stress and strain gradients that promote rapid dislocation multiplication. This leads to forest dislocation hardening and additional work hardening due to the interaction of dislocations with LCO regions. The dual work hardening mechanisms restrain and stabilize premature necking, leading to a ductility of approximately 20% and a yield strength of 2 GPa at both room temperature and cryogenic temperatures. The findings offer a new paradigm for controlling instability and achieving synergistic work hardening to overcome the strength-ductility trade-off in ultrahigh yield strength materials.The study explores the harnessing of premature necking in multi-principal element alloys (MPEAs) to achieve superior strength and ductility. Specifically, it focuses on the VCoNi alloy, which contains local-chemical-order (LCO) regions as built-in heterogeneities. The research demonstrates that Lüders banding, an initial tensile response, induces localized necking at the band front, creating triaxial stress and strain gradients that promote rapid dislocation multiplication. This leads to forest dislocation hardening and additional work hardening due to the interaction of dislocations with LCO regions. The dual work hardening mechanisms restrain and stabilize premature necking, leading to a ductility of approximately 20% and a yield strength of 2 GPa at both room temperature and cryogenic temperatures. The findings offer a new paradigm for controlling instability and achieving synergistic work hardening to overcome the strength-ductility trade-off in ultrahigh yield strength materials.