In Neptun you and your fellow players are merchants in ancient Rome. The Gods are moody and the sea can be treacherous. The players deliver various commodities to the seaports of the Mediterranean area. In a drawing phase players not only try to secure the best assignments for themselves but also influence over the capricious winds. Once the players have said their prayers and start sailing, Neptun will show whom he favours and whose ships he will send on an odyssey.