From A Wiki of Ice and Fire
Cyvasse is a game for two players featuring ten pieces with different powers and attributes.
The cyvasse board changes from game to game, depending on how the players arrange their home squares. It begins with each player arranging their squares and mountains in secret. Each player in his turn moves pieces across a board of alternating colored squares.
The game of cyvasse was introduced to Westeros by a Volantene trading ship at the Planky Town in Dorne. It was 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 learns the game from her betrothed, Trystane Martell, when she comes to live with him in Dorne. Prince Doran Martell places a cyvasse table in Princess Arianne's chambers so she can learn the game. She, however, ignores 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, plays the custom officer Qavo Nogarys to gain information from him. When he becomes a slave of Yezzan zo Qaggaz, Tyrion plays a game of cyvasse with Ben Plumm.
The Winds of Winter
As the Second Siege of Meereen is commencing a Yunkish nobleman enters Brown Ben's tent during a meeting. When he recognises Tyrion he demands that the the dwarf be surrendered for punishment. Ser Jorah opens the Yunkish nobleman's throat with his longsword. The man takes two wobbly steps, falls across the cyvasse board, scatters the wooden armies everywhere and dies on the carpet. A cyvasse piece ends up at Tyrion's feet. It is the white dragon. He scoops it off the carpet and wipes it on his sleeve, but some of the Yunkish blood has collected in the fine grooves of the carving, so the pale wood appears to be veined with red.
|“||The white cyvasse dragon ended up at Tyrion's feet. He scooped it off the carpet and wiped it on his sleeve, but some of the Yunkish blood had collected in the fine grooves of the carving, so the pale wood seemed veined with red. "All hail our beloved queen, Daenerys." Be she alive or be she dead. He tossed the bloody dragon in the air, caught it, grinned.||”|