We study the effect of nitrogen on the morphological evolution of thin silver (Ag) films deposited on weaklyinteracting amorphous carbon (a-C) and silicon oxide (SiO x) surfaces. Films are synthesized at a deposition rate of 0.1 nm⋅s-1 by direct current magnetron sputtering (DCMS), high power impulse magnetron sputtering (HiPIMS), and electron-beam evaporation (EBE). We monitor growth in situ and in real time by measuring the evolution of film stress and optical properties, complemented by ex situ analyses of discontinuous-layer morphologies, film crystal structure, and film composition. We find that addition of molecular nitrogen (N 2) to the plasmagenic gas (Ar) during DCMS and HiPIMS promotes a two-dimensional (2D) morphology. Concurrently, EBE-deposited films exhibit a significantly more pronounced three-dimensional morphological evolution, independently from the gas atmosphere composition. We argue that the 2D morphology in DCMS-and HiPIMS-grown films is enhanced due to incorporation of atomic nitrogen (N)-result of plasma-induced N 2 dissociation-that hinders island reshaping during coalescence. This mechanism is not active during EBE due to the absence of energetic plasma electrons driving N 2 dissociation. The overall results of the study show that accurate control of vapor-phase chemistry is of paramount importance when using gaseous species as agents for manipulating growth in weakly-interacting film-substrate systems.