This study examines the integration of ionic liquids (ILs) with gadolinium diamond-like carbon (Gd-DLC) films as a means of addressing the environmental drawbacks associated with conventional additives, such as zinc dialkyldithiophosphates. Tribological testing initially revealed that higher concentrations of gadolinium in the DLC resulted in improved wear resistance. Further observation of the wear tracks confirmed no corrosion typically seen in steel under bromide-containing ILs, thereby demonstrating the protective capabilities of Gd-DLC. Advanced surface analysis techniques revealed that increased gadolinium content enhances phosphate adsorption, resulting in the generation of protective tribofilms. These findings indicate that Gd-DLC and ILs have the potential to develop sustainable and efficient lubrication systems, significantly enhancing both performance and environmental compatibility of mechanical applications.