Geoff is a character from Strife. He is a man whom the player initially encounters in the Old Town Hall. He will have nothing to say to the player initially except "Walk away boy, just walk away.".
It is revealed early in the game that Geoff is actually the guard who polices the entrance to The Front's initial base in the old town hall at the beginning of the game. When Rowan first hands player the comlink enabling him to make contact with Blackbird (and, consequently, the Front as a whole), one of the first things Blackbird tells the player is the password needed to get by Geoff and enter the Front's headquarters. After Geoff opens the entrance for the player, his continued existence in the game becomes irrelevant. In fact, even after The Front has moved its base to The Order's castle midway through the game, Geoff still wanders around outside of the old (now abandoned) Front base and will continue to do so indefinitely unless the player kills him.
Killing Geoff is optional. There is a secret switch to open the door to enter the base. Geoff does not turn off any alarm. It is unknown whether or not that was supposed to have been implemented. Killing Geoff gives an ammo clip.