It is not vulnerable for the simple fact that Gettier cases are only true due to an element of luck. For example, a specific case of Gettier that explains this is the “Fake Barn Country” example we discussed in class. This example deals with a man driving through a barn. The town of barns is actually just a facade of fake barns, but there is a real one throughout the town. The man stops right in front of the only real barn in the whole town. Because he sees a real barn in front of him, he believes that the entire country consists of real barns. The man's arrival at the one true barn is completely due to chance, and the knowledge of the reality of the barn is also due to chance. This element of luck, once again, makes the belief true, but it does not meet Zagzebski's definition