The following variants are known to have existed, but are lost.
If anyone has a copy the Variant Bank would be very glad indeed to receive a copy!
If you know of the whereabouts of any of these variant, please let me know.
| ARDA | Variant | Designer | Players | Notes |
| cb11 | 3-Man on 9-man board | ??? | 03 | |
| cb10 | 3×3 w/2 wild card players | H. Naus?? | 04 | |
| gh08 | 5-Man Colonia III Fixed Length | ??? | 05 | |
| rb36 | Alias | W.Ives | 07 | |
| rb27 | Balance of Power | A. Phillips | 07 | |
| pb02 | Balkan War (II)-R | Schwartz and Nofi | 05 | |
| rr10 | Black Hole Diplomacy III | ??? | 07 | |
| od01 | Conquest of Australia | Bob Albrecht | 06 | |
| rh08 | Diplodocus I | Paul Meerts | 34 | |
| rew11 | DiProduction | E. Hinton | 22-33 | |
| re04 | Economic Diplomacy III | R. Shagrin | 07 | |
| hb05 | Europe 1650 | C. Alexander | 07 | |
| qp04 | Europe 2010 | ??? | 09 | |
| – | Five Colonials Diplomacy | ??? | 05 | |
| rb26 | Home Sweet Home | J. Gross | 07 | |
| sg13 | Interstellar Diplomacy IV | R. Prevot | 05 | |
| pw01 | Italy, 1500 | C. Alexander | 09 | |
| fn04 | Lemurian Diplomacy | S. Gunnell | 04 | |
| un01 | Lizard | K. St. Andre | Xx | |
| ts12 | Lord of the Rings Diplomacy II | J. Key | 06 | |
| gp17 | Mercator Combined Edition (II-IV, VA, VI-IX) | ??? | 13-24 | |
| gp08 | Mercator II | Doug Wakefield | 13 | |
| gp09 | Mercator III | Doug Wakefield | 13 | |
| gp10 | Mercator III 1/2 | Doug Wakefield | 13 | |
| gp07 | Mercator II-VB complete | Doug Wakefield | 14 | |
| gp11 | Mercator IV | Doug Wakefield | 13 | |
| gp12 | Mercator IVSF (“Samson Flansteed”) | Doug Wakefield | 07 | |
| gp13 | Mercator IVSF-WINS (“With nastier stabs”) | Doug Wakefield | 07 | |
| gp22 | Mercator IX | ??? | 24 | |
| gp14 | Mercator V-A | Doug Wakefield | 14 | |
| gp15 | Mercator V-B | Doug Wakefield | 14 | |
| gp19 | Mercator VI | ??? | 15 | |
| gp20 | Mercator VII | ??? | 19 | |
| gp21 | Mercator VIII | ??? | 21 | |
| – | Mercator XI | ??? | ? | |
| gp23 | Mercator XII | Doug Wakefield | 18 | |
| – | Mid East | ??? | 06 | |
| ts08 | Mordor v. the World III | Alderson and Miller | 05 | |
| cc05 | Morglay | Alderson and Pournelle | 07 | |
| gf13 | Nuclear Holocaust | ??? | 13 | |
| ed26 | Nuit et Brouillard (Night and Fog) | Philippe Crepey | 07 | |
| rs27 | Pudge Don’t Budge | John Caruso | 07 | |
| rs30 | Python Diplomacy | D. DelGrande | 07 | |
| vj07 | Rather Silly Diplomacy I | Jeremy Maiden et. al. | 11 | |
| qr02 | Re-Discover | Richard Bartle | 07 | |
| cb22 | Saharan Diplomacy (I) | Bahjat Sharif | 07 | |
| cb02 | Scheisskopf Diplomacy II | Donald Wileman | 07 | |
| pi04 | Scotice Scripti I | Peter Comber | 08 | |
| rm25 | SER Optionals | Scott Rich | 07 | |
| rm19 | Simulation Diplomacy I | R. Shagrin | 35 | |
| rb24 | Slimak’s Rule | K. Slimak | 07 | |
| es02 | Southeast Asia ’56 | J. Massar | 07 | |
| ug09 | Space War | D. Alderson | 04 | |
| re05 | Super-economic Diplomacy (Dollar Diplomacy) | F. Mulhauser | 07 | |
| rt03 | Team Game (3×3) with Wild Card Player I | Don Miller | 07 | |
| rt05 | Team Game (3×3) with Wild Card Player IV | Don Miller | 07 | |
| vj05 | Trader (I) | M. Diller | 05 | |
| rx06 | Two-Man Diplomacy | H. Naus | 02 | |
| rx08 | Two-Man Diplomacy | Larry Peery | 02 | |
| rx09 | Two-Man Diplomacy (FRT v. EGI) | B. Lindsay | 02 | |
| nu07 | United States Diplomacy I | C. Reinsel | 02-16 | |
| cb04 | Variation C | Bob Johnson | 07 | |
| gf18 | World Diplomacy II | Mark Stegeman | 08 | |
| gf19 | World Diplomacy III | Mark Stegeman | 08 | |
| gf22 | World Diplomacy V | William Stapel | 07 |