By the way, while we are talking about the multiverse, I wanted to offer this trivia.
I wanted to call it a "fun fact," but it isn't. It's one of those things I wish I could unlearn. And since I can't, I'm going to inflict it on everyone else.
Oerth (the world that Greyhawk is on) ... how do you think it is pronounced?
Go on.
Oerth. How do you pronounce it? Say it out loud to yourself.
If you're like me, you probably pronounce it something like O-erth. (Slight stress on a long O, followed by earth)
But how was it actually pronounced? By Gygax? Do you really want to know?
I'll put it in spoilers, because, trust me, you can't unlearn this.
OY-th, as if you had a strong Brooklyn accent. I'm sorry.