A role playing game is only a role playing game when the official creator says its a role playing game. If you take the term role playing game literally every game is an RPG and with lots of games these days its not uncommon for them to have parts of different genres. The catagorey isnt a big deal anyway. It just helps random buyers get an idea of what theyre purchasing. I guess Id consider it a role playing game when the main aspect of the game is the story rather than gameplay. Thats why Id call Legend of Zelda an adventure game.