Over the past two decades, research efforts aimed at identifying superior NRR electrocatalysts have increased significantly. Computational mechanistic studies have also been conducted to gain a better understanding of the nitrogen reduction mechanism at the catalyst surface with the aim of guiding the discovery of new NRR electrocatalysts. Computational investigations of NRR catalyzed by metals predicted that NRR on metal surfaces obeys scaling relations between key reaction intermediates, resulting in a classic "volcano plot" for NRR activity, following the Sabatier principle. In particular, the scaling of the adsorption energy of the N2H* state with the adsorption energy of the NH2* state (where * indicates an adsorbed species) was predicted to limit the minimum overpotential for NRR on metals, resulting in poor NRR activity at less reducing potentials and intense competition with the hydrogen evolution reaction (HER) at more reducing potentials. The studies that identified the scaling relations that limit NRR activity have impacted the NRR field profoundly and continue to guide screening studies. However, these studies did not consider the effects of solvation and approximated the fixed electrochemical potential of the electrocatalyst interface using the post-hoc computational hydrogen electrode (CHE) method. Moreover, these studies only considered the proton-coupled electron transfer (PCET) steps of the NRR mechanism (Figure ) because the CHE method and conventional fixed-charge density functional theory (DFT) do not model the bias-dependence of non-PCET steps. Thus, these studies neglect the possibility that non-PCET steps could be rate-limiting under specific electrochemical conditions. Recent studies of NRR on unconventional materials have included non-PCET reaction steps in their analysis and find that ignoring non-PCET steps (i.e., chemical steps) yields qualitatively different activity trends. However, NRR scaling relations on metals have not yet been re-examined using a more complete mechanism that includes both electrochemical and chemical steps under applied bias. Consequently, there is a significant need to re-evaluate NRR scaling on metals using a more comprehensive mechanism and methods that more accurately describe the effects of solvation and the applied potential to determine whether chemical steps play a significant role in directing NRR activity.