Starts with the letter 'Due'
- The Duel . Two hoppers eliminate squares as they go and compete against one another. By Namik Zade.
- Duel Chess. Captured pieces are sent to a separate Duel board to see who is eliminated and who returns. (5x7x2, Cells: 43) By Erez Schatz.
- Duel Chess. PBM Preset for 43-space variant played on two boards. Author: Fergus Duniho. Inventor: Erez Schatz.
- The Duel II . Missing description By Namik Zade.
- Dueling Archbishops. Chess variant on 2 by 3 board. (2x3, Cells: 6)
- Dueling Archbishops . Small chess variant on 2 by 3 board.
- Dueling Archbishops. Chess game with only six cells but with a piece that morphs into four different forms. Author: Jeremy Gabriel Good.
|2 'Game' entries listed||3 'Zillions of Games file' entries listed|
|2 'Play by mail item' entries listed||2 'Large board' entries listed|
|5 'Small board' entries listed||2 'Unorthodox shaped board' entries listed|
Total items listed: 7