Poseidon is a game about prestige, fortune and exploration. Greece, a long time ago. Due to the development of ships suitable for crossing the Ionian Sea, different nation start setting up trading routes and exploring new territory.
Each player represents a rich family clan trying to multiply their riches. You invest in flourishing nations by obtaining merchant licenses and even rule some of those nations if you’re the player with the most merchant licenses equaling highest influence. (The terms ‘merchant’ and ‘merchant license’ will be used synonymous.)
As the ruler of a nation, you send out your discovery ship to establish trading routes and collect income with your merchant fleet.