RPG stands for Role-playing game right? so if you feel like you are playing a role and you are getting into that role, then it is an RPG. My friend likes to sneak up and put people in neck-grabs from behind, so Metal Gear Solid is a role-playing game for him.
My brother (used to, now he talks down the mike to other COD players, the only game he plays) talks to himself when playing a game, he mimics the charactes voices, pretending they say different (and sometimes funny) things in conversation. is that not a form of role-playing, in games ranging from "timesplitters" to "Ratchet and Clank"?
I am fond of a game called Fire-emblem, it is a turn-based-strategy game (would that be TBS or TBSG?) where the main characters are fixed, but you have a choice of which characters to take into battle (excluding the most main character, who has to be there to lead), sometimes a choice over whether or not to recruit someone and you can choose which characters to train/battle the most and therefore which ones to make incredibly strong.
These sound a lot like 'RPG elements' described in a lot of games, but i would strongly disagree that Fire Emblem is not an RPG.
now i think about it, Resident Evil 4/5 could be considered RPGs... you have a choice of which guns to upgrade, you have the choice to move quickly through the level or stay and look for treasure for a bit. you even at some points get choices as to whether to just run from enemies or to turn around and fight. surely that comes down to role-playing.
The point i'm making is, Role-playing isn't really a genre of game, its more whether you choose to role-play/how you role-play in a game. Calling every character a synonym of "penis" and just following the story of FF1 as close as you can, without diverging for any exploration, would surely make that an action adventure game. Sure, it may have been designed to call the strong warrior by your name and the puffy white mage your most pathetic friend's, but its how you play it/see through the game.
Even by reading through this thread i can see a large difference in opinion of what Role-playing is. some people think its definatly got to include turn-based combat, whilst others think "thats not how i'd fight" and cinclude real-time battling (such as Oblivion/Fallout) is the way of the RPG. I am pretty confident i can stand by what i said, Role-playing isn't a genre of game, its whether the player chooses to or not within a game.
I am pretty sure i could-rename a genre of a couple known "RPG's"...
Oblivion- medieval-real-time-adventure game
Final Fantasy(ies)- Linear-storied(or purpose)-adventure-game
it would be easier for my brain that way, then i know that when RPG is mentioned among a group of friends, they are definatly talking about a rocket-proppelled-grenades