From A Wiki of Ice and Fire
Cyvasse is a game, it involves two players, featuring ten pieces with different powers and attributes.
It begins with each player arranging their squares and mountains in secret (The board changes from game to game, depending on how the players arrange their home squares.) then each player in his turn moves pieces across a board of alternating colored squares.
The game of cyvasse, was recently introduced to Westeros, by a Volantene trading ship at the Planky Town in Dorne, it was later spread by the orphans traveling the Greenblood and soon the Dornish court learned to play the game.
- Light Horse
- Heavy Horse
- Dragon - the most powerful piece in the game 
A Feast for Crows
Myrcella Baratheon learned the game from her betrothed Trystane Martell when she came to live with him in Dorne. Prince Doran placed a cyvasse table in Princess Arianne's chambers so she could learn the game. She, however, ignored it.
A Dance with Dragons
Cyvasse is played during Tyrion Lannister's voyage on the Shy Maid. It is used not only to pass the time but to obtain information and to make wagers. Tyrion, under Haldon's direction, played Qavo Nogarys, a custom officer to gain information from him. When he became a slave of Yezzan zo Qaggaz, Tyrion plays a game of cyvasse with Ben Plumm.