Jump on board the good ship Tranquility and set sail for paradise. Take care, though, because in a land where the day blends into night it's easy to lose track of time and you still need to find that special little island to call home.

Tranquility is a co-operative card game in which players must fill the sea with islands - specifically island cards with numbers on them - and guide the ship home before any player runs out of cards. Note that in the world of Tranquility, the only way to play is in silence.

The goal of the game is for the team to complete the grid before any player runs out of available actions. Cards must be placed so that the grid ascends in numerical order from bottom left to top right. All the players win if they manage to complete the grid and have placed a Start and Finish card. All players lose if a single player can no longer play or discard any cards legally following the instructions given below. The players may not, however, communicate.

Play is taken in turns moving clockwise with the quietest player going first. On a player's turn they must do one of the following: 1. Play a card or 2. Discard two cards. Then they must draw back up to a hand of five cards. Cards must be placed so that the grid ascends in numerical order from bottom left to top right. If the card is placed next to an existing card in the sequence then they must discard cards from their hand equal to the difference between the numbers face down in front of them e.g. placing a 5 next to a 3 will require two cards to be discarded from their hand. This applies even if the cards are on different rows.