1660 is a strategic game in which the players take the roles of European powers (Spain, France, the United Provinces, and the English Commonwealth) and try to extract wealth from their colonies and conquer those of other players.
The game is played over three years, at the beginning of each of which the players collect taxes and can build ships and armies. There are then fourteen movement and combat turns each year. Ships are moved via dice roll (reflecting the unpredictability of the winds), but players can choose how to allocate each die. There are also prevailing winds and currents which can affect movement.
Players can attack other players' colonies, but can also send merchant ships to obtain trade goods and carry them back to home ports (where they add to the treasury) or send warships to attack other players' treasure fleets. There are occasional random events.
At the end of three years victory points are awarded for gold in the treasury, ships, and captured colonies. Each nation subtracts a different amount from their final score to reflect imbalance in the positions; each nation starts with different amounts of money and units, and also collects a different amount of taxes each year.