Poseidon is angry and blowing the ships around on the sea in unknown ways. As a group against a god the players are trying to get the four ships to the sacred isle in the middle of the map. With relatively simple maps it would seem like an easy task to get to complete the objective but Poseidon also gets turns where he moves your ship as well - sometimes he can even move everyone's ship at once!
On your turn you will tell the Poseidon player which direction you are moving. You can go in all 8 of the possible directions but only one space. Then Poseidon will tell you what if anything you see and whether or not you are in deep water. If you are on an island then you will find out what kind of island it is. You must use the information in order to determine where you have sailed. The players can manipulate the board in front of them as much as they want to if they feel their boat is in the wrong place then they can just move it to where they think is correct.
The true map - the one that shows the accurate position of all of the ships is hidden from everyone but Poseidon’s view. If the player gets to the sacred island he does have to let that player know but other than that the only information he needs give is what the players receive on their turn after moving. Just like how the ship players seem like they have very obvious jobs to accomplish there is some strategy to playing Poseidon as well.
Once you learn how to play Odyssey the game develops more and more depth. Players will learn to assume that their ships will get blown off course. But what if the winds actually helped them? As Poseidon I have had a lot of fun helping out a ship or two and watching them dash past the sacred isle never realizing until the end of the game how far off they were.
Odyssey is also somewhat of a deduction game which makes this three in a row but the aspect of having one player versus many adds some flavor to the puzzle being solved that isn’t present when you are just competing to solve the puzzle of the game quicker than the other players. And that added bit of evil and human interaction is what places it above the other recent deduction games.