In Underwater Cities humanity has realized it is time to establish a new home on the ocean floor. Kelp farms can provide food. Desalination plants can provide water. And laboratories can provide the technology needed to build a network of underwater cities.

Players direct the founding of their own underwater nations. They collect resources to build cities, a transportation network, and the facilities necessary to support life under the sea. Everything is accomplished by playing cards to choose various actions. If the card matches the action, the player also gains a benefit from the card.

At times, the action may be so important that the player will choose it even with a non-matching card. At other times, the benefit of the card may be so good that any action is acceptable as long as the card matches it. Balancing these choices is the key to building an underwater habitat in which humanity can thrive.

The New Discoveries expansion offers many new challenges to players. New asymmetric assistants and starting resources help speed up the Game. 52 new cards to add even more choices. New 3-layered player boards upgrade the boards from the existing Game, plus 4 new double-sided boards. The Museum Of underwater artifacts board offers enticing treasures. New metropolises provide even more variability from Game to Game.

Two bonus Starship pin back buttons.