This is one of those that causes arguments between me and certain of my players.
They argue that because it's fantasy, then playing non-humans is what it's all about. Humans are boring and they want to play something 'different'.
I don't allow non-humans in my games, as a rule, although I may soon make an exception in order to prove a point.
The argument is that playing a non-human represents a challenge to the roleplaying talents of the players, and the experienced rpg-ers want the challenge of being different.
My response is that playing a non-human is a cop out. If you want to be an advanced roleplayer, then play a human and make them different. From across many years and many groups and individuals, I find that too many people believe that 'good roleplaying' and 'different' non-human characters are represented by such pointless nods to 'culture' as the austere silence (in an rpg? do me a favour...) and a high degree of racial predjudice. I don't have a problem with gloranthan elves and dwarves not being the best partners in the sandpit, but I find the concept far more interesting from a human viewpoint, rather than knowing that all of that beautiful cultural background is ultimately going to result in "What's your strike rank with that weapon?". Then it goes from bad to worse when non-human pc's have to come up with a reason for being unlike other typical members of a race in order to bypass the inconveniences attached to that race. Thus, an entire elder race gets represented/libelled by some pseudo-intellectual roleplayer who thinks that they're being 'different' and 'a good roleplayer'. It also occupies other player's time which is spent doing all of those pointless things that remind everyone that your character is an elf, or a dwarf, or The Crimson Bat.
Trying to wrap your head around the psychlogical implications of playing a non-human may seem like fun and may even seem clever. Everyone, myself included, thinks they can do it, but I've seen the reality too many times to buy into it any more...
Humans - Know your Limits...