Improved toughness is one of the central goals in the development of wear-resistant coatings. Previous studies of toughness in transition metal nitride alloys have addressed the effects of chemical composition in these compounds. Herein, we use density functional theory to study the effects of various metal sublattice configurations, ranging from fully ordered to fully disordered, on the mechanical properties of VM2N and TiM2N ( M2 = W,Mo) ternary alloys. Results show that all alloys display high incompressibility, indicating strong Me-N bonds. Disordered atomic arrangements yield lower values of bulk moduli and C-11 elastic constants, as well as higher values of C-44 elastic constants, compared to ordered structures. We attribute the low C-44 values of ordered structures to the formation of fully-bonding states perpendicular to the applied stress. We find that the ductility of these compounds is primarily an effect of the increased valence electron concentration induced upon alloying. (C) 2014 Elsevier B.V. All rights reserved.