Mastermind said:
Combat mechanics aside, the staple of a RPG is player driven character development. If you're playing a pre-made character, even if you can adjust his stats, it takes away a great deal of its RPGness.
I have to quote J.E Sawyer on this topic, as i found his definition of rpgs be close to mine:
"I don't have any difficulty classifying them because I don't intrinsically link styles of combat with the RPG genre. I classify games as RPGs based on their interactive storytelling. More specifically, if you have the ability to define and express your character(s) personality in a way that significantly alters the development of the story, it's an RPG. If you don't have that ability, it's not."
"Don't get me wrong; I like character statistics and advancement. I think they should be part of all sorts of games, and I appreciate it whenever I can get it. But when it comes to the sort of games I help make that are going to be called "RPG", it's important to me that we always do our best to actively support the player's ability to the sort of character they want to make -- with a heavy focus on personality reactivity."