The Guksu (Korean: 국수전, Hanja: 國手戰) is a Go competition in South Korea.
The Guksu is a Go competition held by the Hanguk Kiwon, and sponsored by The Dong-a Ilbo. It is the longest running competition in South Korea. Even though it is no longer the largest tournament in terms of prize money, many people still consider the Guksu title (Guksu literally means hand of the nation or the best player in the country) to be the most prestigious of all Korean titles, especially given its long tradition.
The white Ho-Sun (Komi, in Japanese) is 6.5 points, which is a compensation (handicap) given to the white-stone player for starting after the black-stone player. In the preliminaries, players are given 3 hours to play their matches. In the knockout league, players are given 4 hours, and in the final title match players are given 5 hours. The winner's prize is 40 million KRW (appr. $37,000,-).