Stefan is the Surgeon's test subject or more politely referred to as an "assistant." It took a considerable amount of trepanning (and radiation medicine) for Stefan to become docile and loyal. Stefan's job is to maul or cloak in radiation any intruder that dares threaten his master, as well as test subjects the Surgeon deems too unruly or not reacting properly with their implant chips. These are never referred to as "mistakes" though; the Surgeon doesn't make mistakes.
Interactions with the player characterEdit
Effects of player's actionsEdit
Since the Surgeon "reprogrammed" its mind, it is non-hostile unless the Lone Wanderer kills its master.
Stefan appears only in Fallout 3.
PC Playstation 3 Xbox 360 After killing the Surgeon, Stefan will occasionally not turn hostile like he normally should. [verified]