One thing I have noticed in the past year ANY game with a leveling system is now considered a RPG. I'm not trying to make the game look bad. So cool it fan boys/girls.
There are two major factors a game has to qualify to be considered a role playing game.
Game play: games that are considered are RPGs must have a leveling system that is derived from base stats (like luck and strength) then secondary stats (such as explosives and first aid) then the most important one is party selection! Such as having tanks, healer, and damage dealers.
Character background and story: In RPGs games you are normally able to develop a strong background of your character. Then you are allowed to make multiple choices and different dicesions ( a few good and a few bad) with out making your character seem totally bi-polar.
for mass effect
Game play: the so called powers are little more then tiny perks. There no depth to them or your weapons. You don't even need a proper party selection on any diffuclty.
character background and story: granted mass effect does have a Little back ground selection but it doesn't go to far. You really can't be much more then a liberial goodie two shoes or jack @@@ cop. There just very little character customization.
So in all mass effect is not a rpg but a action third person shooter.