hi all - my twins (9 years old) love warcraft 3. they've pretty much mastered the game to the point where it's not a challenge for them anymore. they would like to play wow, but i'm concerned about them going online. my question is can wow be played as a "standalone" game, or do they have to play in an online format? i checked out blizzard.com and didn't really see anything about standalone, so i'm guessing it's designed for online play only? also, if it is possible to play standalone, does the person still have to pay any sort of monthly fee? thx!