From publisher blurb:
Robot Defenders: Shadow Over Area 52 is an Open-Source Adventure designed for any system but geared to alternative 5e D20 OGL (EssenceD20). When the forces of Shadow team up with the CyberBot Enforcers, shape changing robots from another planet, the Robot Defenders must roll into action to thwart the villains' plans. This Four Act Adventure includes missions such an investigation in Las Vegas, a mystery at an old mining town, an assault on a Military command base and concluding in an outer space battle. The Adventure can be scaled for any Tier of play with color maps, game aids, optional rules and optional character write ups for vehicles and NPCs for a specific Essence20 system. Can the Defenders prevent Shadow and the Enforcers from achieving their goal of world domination?