Quaternary CrMoCxN1-x coatings were deposited on steel substrates (AISI D2) and Si wafers by a hybrid coating system combining an arc-ion plating technique and a dc reactive magnetron sputtering technique using Cr and Mo targets in an Ar/N-2/CH4 gaseous mixture. The carbon content of CrMoCxN1-x, coatings was linearly increased with increasing CH4/(CH4+N-2) gas flow rate ratio. The maximum hardness of 44 GPa was obtained from the CrMoCxN1-x, coatings containing a carbon content of x=0.33 with a residual stress of -4.4 GPa. The average friction coefficient of Cr-Mo-N coatings was 0.42, and it is decreased to 0.31 after applying CrMoCxN1-x coatings. This result was caused by the formation of a carbon-rich transfer layer that acted as a solid lubricant to reduce contact between the coating surface and steel ball. The microstructure of the coatings was investigated by x-ray diffraction, scanning electron microscopy, and x-ray photoelectron spectroscopy. In this work, the microstructure and mechanical properties of the CrMoCxN1-x coatings were systematically investigated with the instrumental analyses. (C) 2008 American Vacuum Society.