The basic meaning of "Ryu-oh" is a "promoted rook". It can move as either a rook (hisha 飛車, lit. flying chariot") or a king (gyokushō 玉将, lit. "jade general") during a turn, and is one of the two most powerful pieces in shogi.
"Ryu-oh" also refers to the annual Ryu-oh Tournament (Ryūō-sen 竜王戦) sponsored by the Yomiuri Shimbun as well as the title awarded to its winner. The Ryu-oh Tournament, which is one of the seven major professional shogi title matches, was first held in 1988. It comprises preliminary tournaments in six classes and one final. The final tournament, which determines the challenger, involves competitions among eleven players (the top five players from 1st class, top two from 2nd class, and the top four from 3rd, 4th, 5th and 6th classes). The first player to win four out of seven championship games becomes the new titleholder. This title should not be confused with that of "Amateur Ryu-oh" which is awarded each year to the winner of the Amateur Ryu-oh Tournament.
Cash prizes are ¥32,000,000 for the winner of championship and new Ryu-oh titleholder, and ¥8,000,000 for the loser (approximately US$320,000 and $80,000 respectively). Additional compensation includes ¥14,500,000 for the previous titleholder and ¥7,000,000 for the challenger (approximately US$145,000 and $70,000).
"Lifetime Ryu-oh" ("Eisei Ryu-oh") is the title awarded to a player who wins the championship five times in a row or seven times in total. Active players may qualify for this title, but it is only officially awarded upon their retirement or death. 
The only player to qualify for the Lifetime Ryu-oh title to date is Akira Watanabe[ja]; Watanabe qualified for the title by winning his fifth championship in a row in 2008. He will be officially designated as "The First Lifetime Ryu-oh" upon his retirement or death.
|1||1988||Akira Shima||4-0||Kunio Yonenaga|
|2||1989||Yoshiharu Habu||4-3||Akira Shima|
|3||1990||Koji Tanigawa||4-1||Yoshiharu Habu|
|4||1991||Koji Tanigawa||4-2||Taku Morishita|
|5||1992||Yoshiharu Habu||4-3||Koji Tanigawa|
|6||1993||Yasumitsu Sato||4-2||Yoshiharu Habu|
|7||1994||Yoshiharu Habu||4-2||Yasumitsu Sato|
|8||1995||Yoshiharu Habu||4-2||Yasumitsu Sato|
|9||1996||Koji Tanigawa||4-1||Yoshiharu Habu|
|10||1997||Koji Tanigawa||4-0||Keiichi Sanada|
|11||1998||Takeshi Fujii||4-0||Koji Tanigawa|
|12||1999||Takeshi Fujii||4-1||Daisuke Suzuki|
|13||2000||Takeshi Fujii||4-3||Yoshiharu Habu|
|14||2001||Yoshiharu Habu||4-1||Takeshi Fujii|
|15||2002||Yoshiharu Habu||4-3||Takashi Abe|
|16||2003||Toshiyuki Moriuchi||4-0||Yoshiharu Habu|
|17||2004||Akira Watanabe||4-3||Toshiyuki Moriuchi|
|18||2005||Akira Watanabe||4-0||Kazuki Kimura|
|19||2006||Akira Watanabe||4-3||Yasumitsu Sato|
|20||2007||Akira Watanabe||4-2||Yasumitsu Sato|
|21||2008||Akira Watanabe||4-3||Yoshiharu Habu|
|22||2009||Akira Watanabe||4-0||Toshiyuki Moriuchi|
|23||2010||Akira Watanabe||4-2||Yoshiharu Habu|
|24||2011||Akira Watanabe||4-1||Tadahisa Maruyama|
|25||2012||Akira Watanabe||4-1||Tadahisa Maruyama|
|26||2013||Toshiyuki Moriuchi||4-1||Akira Watanabe|
|27||2014||Tetsuro Itodani||4-1||Toshiyuki Moriuchi|
|28||2015||Akira Watanabe||4-1||Tetsuro Itodani|
- Most titles overall: Akira Watanabe, 10
- Most consecutive titles: Akira Watanabe, 9 in a row (2004-2012)
- Most times recapturing title: Yoshiharu Habu, 3 [a]
- Longest period between titles: Toshiyuki Moriuchi, 10 years (2003-2013)
Games played outside Japan
29th Ryu-oh challenger controversy
Hiroyuki Miura 9d won the three-game challenger playoff match for the 29th Ryu-oh tournament by defeating Tadahisa Maruyama 9d two games to one in early September 2016. Three days before Miura was to begin play against reigning Ryu-oh Watanabe, however, the Japan Shogi Association (JSA) announced that Maruyama was replacing Miura as the challenger. The official reason given by the JSA had to do with Miura failing to follow proper procedure in requesting to be allowed to withdraw from the match, but there also had been suspicions raised about Miura's recent frequent leaving of his seat during official shogi games. Suspicions had been raised that he was doing so to consult shogi software or an app installed on a smartphone. Miura denied the accusations at a meeting of the JSA managing directors on 11 October, and said he was withdrawing from the upcoming title match because he could not play shogi under such circumstances. The JSA said that Miura failed to submit an official notification of withdrawal by the required deadline on 12 October and as a result Miura was suspended from official game play until 31 December 2016.
- Habu lost the title for first time in 1990, but won it back in 1992. He lost the title again in 1993, only to recapture it for the second time in 1994. He lost title for the third time in 1996, but recaptured it again five years later in 2001.
- "Purokisen no Kitei ni Kansuru Goshitsumon - Q: Eisei Shōgō no Kitei wa Dō Natteiru no Deshōka" プロ棋戦の規定に関するご質問 — Q:永世称号の規定はどうなっているのでしょうか。 [Questions Regarding Professional Shogi— Q: What are the requirements for lifetime titles?] (in Japanese). 日本将棋連盟 (Japan Shogi Association).
- "Watanabe Akira Ryūō no Kyōdō Kisha Kaiken" 渡辺明竜王の共同記者会見 [Akira Watanabe Ryu-oh, Kyodo News Press Conference] (in Japanese). 日本将棋連盟 (Japan Shogi Association). 19 December 2008. Retrieved 7 August 2014.
- "Itodani Shin-Ryūō ga Tanjō, Taitoru Hatsuchōsen de Dasshu" 糸谷新竜王が誕生 タイトル初挑戦で奪取 [New Ryuo Itodani Is Crowned. Captures Major Title on First Try]. Nihon Keizai Shimbun (in Japanese). 4 December 2014. Retrieved 5 December 2014.
- Fukamatsu, Shinji (3 December 2015). "Watanabe Kiō ga Ryūō Kaerizaki, Tsūsan Jikkime" 渡辺棋王が竜王返り咲き, 通算10期目 [Watanbe Kio recaptures Ryuo Title for the 10th Time Overall]. Asahi Shimbun (in Japanese). Retrieved 11 December 2015.
- "Kaigai Taikyoku no Reikishi" 海外対局の歴史 [History of major title match games held overseas] (in Japanese). Yomiuri Shimbun & 日本将棋連盟 (Japan Shogi Association). 17 October 2014. Retrieved 22 October 2014.
- "Dai Nijūnanaki Ryūōsen Nanaban Shōbu" 第27期竜王戦七番勝負 [27th Ryu-oh 7-game Match] (in Japanese). Yomiuri Shimbun & 日本将棋連盟 (Japan Shogi Association). Retrieved 22 October 2014.
- Gordon, Larry (18 October 1996). "Shogi Makes a Move: Stars of Chess-Like Japanese Game Play Tourney Round in L.A.". Los Angeles Times. Retrieved 7 July 2016.
- Burress, Charles (12 October 2006). "Venerable Japanese game's high-stakes battle / Shogi players vie for title and $300,000 -- contest brought to U.S. to boost interest". San Francisco Chronicle. Retrieved 7 July 2016.
- Mark, Steven (14 October 2014). "Professional Shogi Tournament to Kick Off in Isles". Honolulu Star-Advertiser. Retrieved 7 July 2016 – via PressReader.
- Murase, Shinya; Fukumatsu, Shinji (13 October 2016). "Top 'shogi' player suspected of cheating pulls out of title match". Asahi Shimbun. Retrieved 17 October 2016.
- "Top shogi player banned amid cheating allegations". Mainichi Shinbum. 13 October 2016. Retrieved 17 October 2016.