Star Wars like all movies has a protagonist or main character. In this film it is Luke Skywalker, a young and smart kid who is edgar to leave his bland home plaint. This alone is one of the most used stereotypes for a main character, but it doesn't stop there. Luke is also parentless (or at least we think) and raised by his aunt and uncle. Luke also discovers that his father was a jedi and he has the capability of becoming one him self. This is a very common character, so common why do they bother using it? 1st reason is that during the time it came out this type of character wasn't as common as it is now. 2nd reason is that the underdog stereotype may be common but it sell well at the box office. The 3rd reason is this stereo type is almost comfort for a viewer in new setting. If the setting is new with all sort of different thing that could be strange for a viewer. but if you add the common hero to the story the viewer would feel more at home and more compelled to watch the movie. That is the reason they made Luke Skywalker in the first place, for hero that the audience can route for!