What is more perplexing are the roleplayers who practice a more subtle form of godmode. I'll call it "roleplay 'blackmail". In this form of godmode, a roleplayer uses situations, settings, or NPCs in a way that would drastically change the way the world works, making it impossible for other characters to rationally be unaware of what happened in that part of the world, or not to become involved, whether their player actually wants to or not.
EXAMPLE: Let's say I have a character who is the Protector of the Patch, and she guards the pumpkin patch inside the City of Stormwind. Any player can wander by, and see pumpkins growing in the patch. While the NPCs don't actively talk about The Patch Protector, they don't do or say anything that directly contradicts the existence of that character.
Now let's say that another player has created a character he calls The Pumpkinator. At some point, the nefarious Pumpkinator declares that he has destroyed the pumpkins in the Patch Protector's patch.
There is nothing in the game to support this scenario. Pumpkins are still growing peacefully in the patch. The NPCs aren't all in a panic. The world has not changed one iota. And yet... he persists in this storyline as though it were reality for all, including my Patch Protector. Possibly, others may decide that they liked that Pumpkin action, and go along with it. In any kind of shared reality, my Patch Protector would KNOW such a thing happened. She'd be forced to either act to stop it, or deal with the aftermath. But at this point -- it's as much make-believe as if I decided that the Patch Protector went insane and killed King Wrynn, and wrested control of Stormwind for herself and her precious pumpkins. Should everyone be forced to play along?
But, let's say I don't WANT to have to deal with The Pumpkinator's evil plans. I wasn't invited to develop the story or had any say in how it played out. Maybe I wasn't even aware of it until long after it had happened. So, what should I do if one day The Pumpkinator comes up to the Patch Protector and says "Ha-HAH! How about all those pumpkins I destroyed in your patch?"
What would you do?