Doom RPG dispatches a team of two veteran marines and a rookie scientist to a Union Aerospace Corporation research facility on Earth's Moon after a mysterious distress signal goes out. Whatever they expected to find, nothing prepared them for the reality waiting inside: the forces of Hell have breached the station and turned its staff into the undead.
The backup squad is wiped out on arrival. Scientists inside the facility are working against the player rather than with them. Even the station's AI cannot be trusted. Hunted from every direction, the protagonist must fight to survive, uncover who or what triggered the invasion, and find a way to stop Hell from using the facility as a foothold — with humanity's fate hanging in the balance.