[Senkusha]

We've all been there.  Playing a great game, and then, there's this one player who is either obnoxious, thinks they're the only one in the party, does their own thing, or is just flat out killing the fun.  So the question is, what as Game Master (GM) / DM, do you do to correct the issue?

I've fallen in this mess myself.  I had a great game going.  We were in a Fraggle Rock world.  We had this one guy who somehow was down below forcing the Dozers to build an airplane, while a group of us were topside  exploring the Living Room.  The next thing we know, this character is up with us!  And when we pointed out the fact that he was still underground, he came up with some BS as to how he was in two places at once.  From that moment on, the game went South.  Finally, it ended up we entered a world of Ah! My Goddess, and Yggdrissil was dying.  Ended up destroying the World (you know, everything, because for those of you who do not know, Yggdrissil is the Norse version of the Tree of Life.), because of his narcissistic personality.