Dr. Guerard is a scientist character in Doom RPG.
Dr. Guerard is first encountered in Sector 1. He is initially helpful to the player, for example opening doors to allow further progress in the game. Various scientists describe a conflict between Guerard and Dr. Jensen, who was fired from the UAC.
Guerard acts in a suspicious manner which attracts the attention of several scientists. For example, he steals a handful of Hydrocon vials. He sometimes appears in locations in seemingly a impossible manner, offering no explanation for how he arrived there.