The idea of Atlantys from an out of character perspective is to use a land that even the DM has not entirely detailed. We will all be sort of "making it up as we go." I would like to take credit for the idea, but it belongs to Nicholas Vaughn. A good example he gave me is the following:
DM: Where do you want to play?
PCs: We want to traverse a jungle and end up in a frozen wasteland.
DM: Right on. It appears that Atlantys has both jungles and a huge, frozen mountain. Let's ride!
Below are a few basic notes for the game.
The Island of Atlantys
Atlantea. Atalan. The Risen Island. Atlantys.
This great island rose up in the past two decades out of the ancient sea to the west of Rhetaea. None know its heritage or what its relation to the history of the world might be. So far, everyone sent to Atlantys has either failed to return or suffered tremendous tragedy. Many have been transformed by the experience, but most believe that to set foot upon its shores is tantamount to a curse of death.
The kingdoms of Rhetaea are interested in Atlantys, but have their own politics. For the most part, only fools and vagabonds go to Atlantys. Some minor nobles, merchants, and profit seekers have funded groups to establish a head on the shores of the island, but so far no one has gained a secure foothold.
Many nations treat Atlantys as a convenient dumping ground for their unwanted members. In most nations, crimes which before would have demanded death or exile may now be commuted as “exile to Atlantys.”