In the Mahabharata, the Kaurava princes’ maternal uncle and a skilled dice player was Shakuni.
Shakuni was the king of Gandhara and the brother of Gandhari, the queen of Dhritarashtra. Because Gandhari married Dhritarashtra, Shakuni became the maternal uncle of Duryodhana and his brothers, the Kauravas. Epic traditions portray him as a major adviser to Duryodhana and an opponent of the Pandavas.
His most famous role occurs in the dice game at Hastinapura. Shakuni plays on Duryodhana’s side and defeats Yudhishthira through a gambling match that leads to the Pandavas’ dispossession and exile. Popular retellings often say that Shakuni’s dice were made from the bones of his father and always obeyed him, but this detail belongs to later or regional traditions rather than being equally prominent in every version.
Shakuni is not the Kauravas’ teacher: Dronacharya fills that role.