It'd be cool to see this concept played with using a random generator. All kinds of people, scenarios, situations, etc. could be randomly generated and shuffled through to create a general kind of ambience to the place (city, castle, some random shack in the middle of nowhere, a pigpen, even, all depending on what's generated each playthrough) that the guard's responsible for guarding. Even the guard themselves can build up a character (backstory, personality, actions) each time through this method. Though this might be deviating a little bit from the currently intended text adventure flavor for this seed ...