Items Authored by Young-Hyun Joo
- Annan Shogi . Shogi variant where pieces move like a friendly piece directly behind it (and similar variants). Author: Young-Hyun Joo.
- Avalanche Chess . A popular chess variant, where you advance your opponents pawns. Author: Young-Hyun Joo. Inventor: Ralph Betza.
- Doublestep Chess and Doubletime Chess . All pieces may move twice when moving. Author: Young-Hyun Joo. Inventor: Ralph Betza.
- Hanga Roa . Play Hanga Roa with Zillions of Games! Author: Young-Hyun Joo. Inventor: Juan Pablo Schweitzer Kirsinger and Hernán Marcelo Domínguez Placencia.
- Marseillais Chess . Move twice per turn. Author: Young-Hyun Joo.
- Progressive Chess . A collection of variants with increasing numbers of moves each turn. Author: Young-Hyun Joo.
- Straights . Chess-like Naval Battle game from the end of the 19th Century. Author: Young-Hyun Joo. Inventor: Anne Marriot Watson.