In this work we illustrate the need for consideration of hydrogen as both a compositional changing opportunistic dopant, as well as a strategy for enhancing the ionic conductivity, not only in Li 3 OCl but other hygroscopic solid electrolytes as well. A full defect model combined with a temperature dependent defined chemical potential stability region is necessary in order to outline doping strategies, killer defects, as well as structural changes in a given material. Our results highlight that, when undoped, Li in low ionic conductivities, however, upon consideration of a "pseudo-V Li ", our calculated ionic conductivities are more in line with experimentally observed values. Whilst Li 3 OCl remains a controversial and challenging material, our results show that H may be a source of enhancement in Li 3 OCl, increasing both the ionic mobility due to OH rotations, as well as increasing the effective carrier concentration.