 When a player rolls a one or a six, in addition to producing a unit (or units), they also receive a card.Each card has an event that can be either positive or negative ranging from free transportation for units to one of the foreign ports, to an earthquake that destroys all the units in the warehouse.One of the key strategies is to compel other players to complete inland barge loads from their minehead to the warehouse and to complete sea transport loads and these lessees are charged money for the privilege.