The main principle of the game is card placement. Three colored cards are placed along the edge of the main board into 3 x 5 slots, which are also colored. Ideally players can place cards into slots of the same color. Then they can take both actions and advantages: the action depicted in the slot on the main board and also the advantage of the card. Actions and advantages can allow players to intake raw materials; to build and upgrade city domes, tunnels and production buildings such as farms, desalination devices and laboratories in their personal underwater area; to move their marker on the initiative track (which is important for player order in the next turn); to activate the player's "A-cards"; and to collect cards, both special ones and basic ones that allow for better decision possibilities during gameplay.
All of the nearly 220 cards - whether special or basic - are divided into four types according to the way and time of use. Underwater areas are planned to be double-sided, giving players many opportunities to achieve VPs and finally win.
