Starts with the letter 'U'
- Undecided Chess. Undecided Pawns can change into pieces by moving like them. (8x8, Cells: 64) By Adrian Alvarez de la Campa.
- Undecided Chess. Undecided Pawns change into orthodox pieces by moving like them. By Adrian Alvarez de la Campa.
- Unidirectional arrays on standard boards. Both players in the same direction, as Viking Chess, but on boards of correspondiyng face-to-face variants. By Charles Gilman.
- Univers Chess. A Carrera's Chess variant based on Bruno Violet's Universal Chess. (10x8, Cells: 80) By Fergus Duniho.
- Univers Chess. Play this Carrera's Chess variant with no unprotected Pawns on Game Courier. By Fergus Duniho.
- Univers Chess. Play Univers Chess with Jocly. Author: Fergus Duniho and The Jocly Team. Inventor: Fergus Duniho.
- Universal Handicap Chess . Missing description By Namik Zade.
- Unknown Drop Shogi. It is unknown what kind of piece your opponent dropped. By (zzo38) A. Black.
- Using chess sets to play mini-sukoku (6x6). Missing description (8x8, Cells: 64) By Karen Robinson.
Total items listed: 9