I've found a lot of gamers struggle to understand the real definition of RPG games, so i was looking over GS and other websites and i've found one mod(forgot his name) has given a fantastic definition of it. here is it.M
ost RPGs contain a manner of earning experience and level progression, a manner of customizing the character(s) you control, and progressively stronger and more complex weapons, armor, and/or magic (or magic-type abilities, in the case of a non-fantasy setting). They usually come in one of two main flavors: Western-styl-e RPGs like Baldur's Gate or Elder Scrolls, which often feature real-time or pseudo-real-time combat, open-ended exploration, and many ways to personalize characters as you see fit; and Japanese RPGs like Final Fantasy, which feature turn-based combat, and a strong focus on linear storytelling.
That isn't to say that all RPGs fit neatly into one of these categories, or that elements of one type don't exist in the other. And of course, there are many sub-types, such as strategy RPGs (which feature full turn-based battlefields), action RPGs (which focus heavily on real-time combat), massively-multiplayer online RPGs, and other games that simply defy categorization. In some cases, some standard elements are disregarded (there are no equippable weapons in Blue Dragon, for example), or new ones are introduced (parleying in Vanguard: Saga of Heroes).
As time goes on, I am less concerned with how to fit a game squarely within a genre and more concerned with how those elements fit into a fun and cohesive experience. Games like Dark Cloud 2 and Kingdom Hearts are tough to categorize, because they contain some RPG elements, but feel as much like action/adventure games as they are RPGs. I've heard plenty of arguments for and against Kingdom Hearts (or The Legend of Zelda, or Dawn of Mana, or Dark Cloud, or plenty of others) as an RPG, and I don't know that I could say anything that would change anyone's mind one way or another. As time moves on, the lines that separate one genre from another blur, and we are left with titles that are impossible to shoehorn into a single category with any confidence.