Pong Hau K'i

Pong Hau K'i is a traditional Chinese board game for two players, known in Korea as Ou-moul-ko-no, Umul Gonu or Gang Gonu, with equivalent games played in Thailand, where one is called Sua tok tong, and in northern India, where one is called Do-guti. The board has five vertices and seven edges, and each player has two pieces. Players take turns moving one piece into the adjacent vacant vertex, and a player who cannot move loses. Only one kind of position can make a player lose, so if both players play perfectly the game continues endlessly with no winner. Analysis by P. Straffin showed that it is a draw so long as both players can see two plies ahead. In China and Korea it is a children's game and is often used for childhood education.