in which progress is made

A few months ago, while playing Left 4 Dead, I found myself cowering in a closet, absolutely terrified to go back out and face the horde. I knew that I had to move so the game would continue, but I just didn't want to go out and take my chances. I didn't know at the time that L4D has this sinister AI called The Director, which keeps the game constantly changing depending on what the player does, adjusting things to keep the game fun. For example, if you're cowering in a closet and think you're s