The idea of the world they get sucked into is based on an ancient Archmage creating a sanctum where he can utilize his magic in peace without harming the rest of the world. The idea is that he suckes a littler dirt and sand from all over the multiverse. From Dragonlance to Forgotton Realms, small particaled are teleported in. HOWEVER, he died before he can turn the magic off and it still is absorbing other areas into it and a millenia later the magic has gone crazy and is now absorbing more then just a little sand. It used to absorb small things, then acres, and now towns. The goal is to have the players stop the magic and return home.
...and no they aren't going on a rollercoaster ride to get there.
The premise begins as theys it down to play a game with their DM when literally the world explodes around them and they become their characters. So basically the guy playing a minotaur is now a minotaur with his stats, mentala nd physical. So Suddenly he can't think as well as he used to and the player who used to be a the quarterback can barely lift a sword but finds himself thinking clearly for the first time as his wizard mind takes over. So in a way they are playing a minor dual personality. They are trying to be themselves but their minds are invaded by alien thoughts.
I'm trying to find a way to make a game mechanic that allows them to not only play themselves but their character as well. Think of it this way...the average person can't pick locks. However their character can. If you got caught in the world you suddenly can pick locks how can we establish this. Suddenly they find themselves much greedier. They find themselves looking at the gold coin and not only knows they want it but how they can get it.
I was thinking possably have an urge table. Something that when they come accross that their character wants to do (A dwarf might get drunk, an elf may go dancing) they would be compelled to do so. They would roll it and feel compelled to do so. Or maybe even have it work against them a bit. If they are doing something that is purely their character and they are suddenly reminded that they are not their character suddenly they can't do what they are doing. I'm just having them roll using their level as a bonus. Maybe even ignore the roll entirely with an action point.