If you were ever pressed to come up with three letters that defined MMORPGs more than anything else (other than, y'know, "MMO"... or "RPG"), chances are you'd be dithering between "PUG" and "RNG." Man, we gamers like our acronyms, don't we? Just one more step toward that militaristic online state!
The RNG -- random number generator -- is that tiny unseen subroutine that basically decides whether you're going to get phat lewts or not, whether you're going to hit a mob or miss, and whether the game will have downtime on the one day that week during which you have free to play. Some people swear fealty to the RNG, bowing to it above all. Some curse its very existence, for it has driven lesser people mad from its fickle nature.
So when have you been royally worked over by the random number generator, even though statistically you should have succeeded long before? When did the RNG gods favor you by dropping a major blessing in your lap on the very first try? And what games are you certain have a mean-spirited RNG that try to do everything in its power to drive players insane?