This quote, via Gamasutra, of CliffyB's ... which in turn is via Corvus (who apparently has way more time to write these days than myself and is therefore my nominee to win NaNoWriMo), which was actually prompted by Patrick's comment ... which .... *takes breath* ... is this:
To which my highly elucidated response would be: sort of.
Let me explain. Right now in the interactive fiction I'm writing, the playable character is with his mother (she, in fact, rides on your back for most of this chapter). Now the mother will be a fairly central character through the whole story. So if you decide to strangle her at the first scene, you wouldn't be able to finish the story.
However, it's not really a problem. See, this is all Valve's fault. The concept of a tabula rasa character is interesting, but in reality just doesn't work. Gordon Freeman is not you. You are playing a character named Gordon Freeman, and are therefore bound to the kind of character boundaries of Freeman. You can't shoot an innocent person trying to help you in Half-Life 2 because Gordon would never do that.
The allure of tabula rasa exists primarily in first person shooters because of, well, the first person. That's the narrative I. You are right in the driver's seat. Interactive fiction generally uses second person, so there is the chance for the narrative to contradict your actions. It will tell you that strangling your mother might sound like a good idea, but you'd never actually do it.
The basic way to do that with a first person perspective would be to have the character initiate an inner monologue. Point a gun at a helpful character and pull the trigger, you hear the main character say. "I wouldn't do that." (or something better written). However, thanks to Valve, everyone's convinced that main character dialogue is somehow intrusive. Which is, imho, bunk.