Dragons usually manipulate lesser beings when playing Xorvintaal. A dragon's head servant is known as his Exarch and his other servants are known as dokaal which is also the generic draconic word for humanoids.
Seeing the inherent incompatibility between the draconic races, the Great Game was created by Cuelebre to prevent costly bloodshed from destroying the species. Dragons who play Xorvintaal are enspelled which, in the case of metallic dragons, may cause them to undertake actions contrary to their nature. There were hundreds of precepts in the game and few dragons fully understood the rules. Points were scored based on conquest or by killing opponents although players also scored points by subterfuge.
After the last major battle of Xorventaal, known to most as the Battle of Tus which ended the Shining Blade rebellion, the silver dragon Narcelleglar was defeated and his Exarch, Tolfdir Shay was killed. As per a complicated clause in the rules, the silver dragon was bound to serve the dragon who defeated him. Somehow, the rules were manipulated to allow the victory to go to Arundel Shay, although some believe that he may just be the Exarch of another dragon.
Xorventaal Dragons are bound by unique magics. During the times of the game is when a dragon is most vulnerable. The dragons inate magical abilities are suspended. In the case that a dragon is defeated, they do not regain their spellcasting abilities. Defeated dragons may continue to live as subjects to the dragon who defeated them, but are rendered sterile for life. Overtime, obsession with the great game lead to the downfall of the dragons and by the end of the fourth age, they were considered extinct by most humanoids.