| ARDA | Variant | Designer | Players |
| sa02 | Tactical Foundation Games I / II (Foundation Games II / III) | R. Brooks | |
| rz07 | Tadek Dip (3-way Intimate) | Steve Doubleday | 3 |
| rb13 | Take-Away Diplomacy | D. Alderson (CE 1) | 7 |
| rf12 | Taskdip | Andreas Kueck | |
| rt01 | Team Game (3×3) Italy Omitted | Don Miller (includes rt02) | 6 |
| rt02 | Team Game (3×3) Turkey Omitted | Don Miller (included with rt01) | 6 |
| rt03 | Team Game (3×3) with Wild Card Player I | Don Miller | 7 |
| rt04 | Team Game (3×3) with Wild Card Player II (uses board for 9-Man Diplomacy I (cn02)) | Don Miller | 7 |
| rt05 | Team Game (3×3) with Wild Card Player IV | Don Miller | 7 |
| rb42 | Telepath Diplomacy | Steve Doubleday and Richard Walkerdine | 7 |
| rb31 | Telstar Diplomacy | G. Neiger | 7 |
| cb55 | Ten Players Diplomacy II, (map described in rules) | – | 10 |
| rm21 | Ten-Man Diplomacy II | Glenn Overby (includes rm22) | 10 |
| cb18 | Ten-Man Diplomacy II-R | Glenn Overby (included with cb16) | 10 |
| rm17 | Ten-Man Diplomacy(I) | Keith Black | 10 |
| rm60 | Ten-Player Diplomacy | ?? | 10 |
| rh11 | Terrestrial Chaos | Jef Bryant | |
| rn10 | Terrorism (II) | Jerry Lucas | 7 |
| rm36 | Terrorism I | Will Haven | 7 |
| fy02 | The Age of Young Kingdoms | Kedge Neuman | 5 |
| rw03 | The Aliens | Lew Pulsipher | |
| pb01 | The Balkan War | Rod Wheeler | 7 |
| cs02 | The Cold War, 1946 (“3”) | | 3 |
| ac11 | The Conquerors | Lew Pulsipher | 4 |
| mc05 | The Crusader Kingdoms of Outremer | Duncan Jones and Justin Marx | 7 |
| cs05 | The Dark Ages, 500 A.D. (“6”) | | 6 |
| vb12 | The Day After | Nils Lindeberg and Bjorn von Knorring | 7 |
| fv02 | The Dying Earth I | Lew Pulsipher (map not included) | 2 |
| fv01 | The Dying Earth II | Lew Pulsipher | 7 |
| rm83 | The Enemy Within! | Stephen Agar | 7 |
| vc02 | The Executioner Diplomacy | Michael Stackpole | 6 |
| ma11 | The Faith and the Sword II | Jean-Yves Priou | 6 |
| me02 | The Fall of Constantinople | André Leme-Lopes | 7 |
| qh07 | The Great Patriotic War | Nicky Palmer | 5 |
| rx17 | The Great War | Richard Egan (publisher) (Tournament Rules) | 2 |
| rx22 | The Great War II | ?? | 2 |
| ts10 | The Great Years | Kedge Neuman | 6 |
| pa02 | The Knight of the Slavonian Plain | David Barnsdale | 3 |
| me05 | The Known World | Stephen Agar | 5 |
| em05 | The Lord of Hosts | Tim Collieu | 6 |
| rm23 | The Lords of Law and Chaos | Lew Pulsipher | 7 |
| rb88 | The Mad Italian! | Patrice Verry | 6 |
| lr01 | The Maya | John Boyer | 8 |
| pe06 | The Men Who Would Be King | Jimmy Walker | 10 |
| rb89 | The Pope | Patrice Verry | 8 |
| tf04 | The Silmarillion | Lewis Pulsipher, John Cain and Warner Airey | 8 |
| pf02 | The Spider King | John Robertson | 7 |
| sg05 | The Star Kings | Lew Pulsipher | |
| hc04 | The Struggle for Hegemony in Europe, 1689 – 1815 | Lew Pulsipher | |
| ud03 | The Sundered Worlds | Steve Doubleday | |
| rg17 | The Tarot Variant | Steve Doubleday | 7 |
| rs18 | The Transatlantic Variant | Ron Melton | 7 |
| gf33 | The Twentieth Century | Michael David Roberts | 13 |
| rm28 | There Are Aliens Among Us | Paul Willey | 8 |
| ts06 | Third Age I | Brain Libby | 6 |
| ts07 | Third Age II | Duncan Morris | 6 |
| ts18 | Third Age III | Richard Sharp | 6 |
| ts23 | Third Age IIIb | Mark Nelson | 6 |
| rm13 | Third Man Diplomacy | Buddy Tretick | 21 |
| qh19 | Third Reich | Paul Willey | 7 |
| cs06 | Thirty Years War, 1610 (“7”) | | 7 |
| hb01 | Thirty Years’ War I | Paul Newman | 15 |
| hb07 | Thirty Years’ War II | Lew Pulsipher | 8 |
| rz02 | Three-Handed Diplomacy | Edi Birsan | 3 |
| rz01 | Three-Player Diplomacy | Lew Pulsipher | 3 |
| rd17 | Time Lords | Steve Doubleday | 7 |
| rd30 | Timelords II | Steve Doubleday | 7 |
| ua02 | Timesteps | Lew Pulsipher | |
| rm93 | Tin Cup Diplomacy | Manus Hand and John Woolley | 7 |
| ug14 | Total Balance II | Stephen Agar and Andrew Poole | 8 |
| gp34 | Total War | Theirry Lucas (Rules in French) | 11 |
| rc07 | Totally Random Diplomacy | Paul Bennett | 7 |
| rb120 | Touch | Andy Schwarz | 7 |
| rm72 | Toxic Diplomacy | Phil Reynolds | 7 |
| vj05 | Trader (I) | M. Diller | 5 |
| rm35 | Transmat | Paul Willey | 7 |
| rb28 | Treachery | Martin Janta-Polczynski | 7 |
| rm10 | Treaty Diplomacy | Rod Walker | 7 |
| cm12 | Trieste Split Diplomacy | Fred Davis | 7 |
| rz06 | Trioplomacy | Glenn Overby | 3 |
| rs15 | Tri-State Variant | Rick Brooks | 11 |
| ar02 | Triumvirate | Richard Vedder | 5 |
| ys02 | Troubleshooter | Der Garvey | |
| rb83 | Truth or Dare | Bjorn Westling | 7 |
| rb37 | Tugboat Diplomacy (a modified Gunboat Diplomacy) | Ed Menders | 7 |
| rn28 | Tunnels and Trogs | Eric Willis | |
| ca02 | Turnabout Diplomacy | Fred Davis | 7 |
| uc02 | Twilight Zone Diplomacy | Peter Berlin | 7 |
| rs16 | Twin Earths Diplomacy I | Don Miller | 7 |
| rm11 | Twin Earths Diplomacy III | Lew Pulsipher | 14 |
| rm81 | Twin Earths V | Patrick Lafontain | 7 |
| cb63 | Two Player Abstraction | James Nelson | 2 |
| rx13 | Two-Man Blind Diplomacy | Lee Kendter, Sr | 2 |
| rx06 | Two-Man Diplomacy | H. Naus | 2 |
| rx08 | Two-Man Diplomacy II | Larry Peery | 2 |
| rx09 | Two-Man Diplomacy III (FRT v. EGI) | B. Lindsay | 2 |
| rx05 | Two-Player Diplomacy | Lew Pulsipher | 2 |
| rz04 | Two-Plus Diplomacy | Pete Calcraft | |
| cb37 | U-Boat | Barry Evans | 5 |
| da01 | Uhuru | Larry Peery | 5 |
| rh12 | Ultimate Shambles | Michel Malhomme | 7 |
| rd11 | Ultra-Stab | Malcolm Brown and Paul Pebble (requires rd10) | 7 |
| fn03 | Umbar | Ken St. Andre (derivative of Zelazny’s Amber novels) | |
| vj20 | United Nations Diplomacy | Rick Loomis | 7 |
| nu07 | United States Diplomacy I | C. Reinsel | |
| nu05 | United States Diplomacy II | Fred Davis | 7 |
| nu03 | United States Diplomacy III | Fred Davis | 7 |
| nu04 | United States Diplomacy III ½ (new space names only) | Fred Davis | 7 |
| nu06 | United States Diplomacy II-R | Fred Davis | 7 |
| nu08 | United States Diplomacy IV | James Early | 7 |
| yo02 | Universal A/F Rules Module | Fred Davis & Stephen Agar | |
| rd09 | Universal Stab | Andy Evans and Stephen Agar | 7 |
| rg03 | Unplayable Card Diplomacy | Stephen Agar | 7 |
| ce06 | USA | Tadd Moskal | 8 |
| hc09 | Utrecht I | Chris Northcott (draft version) | 5 |
| hc07 | Utrecht II(starts in 1740) | Chris Northcott and Fred Davis | 5 |
| hc08 | Utrecth III | Chris Northcott | 5 |
| rr08 | Utter Chaos | Scott Rosenberg, Greg Costikyan and Ray Heuer | 7 |
| yp01 | Utterly Ludicrous Diplomacy | Pete Doubleday | 7 |
| rm40 | Utterly Ruthless Diplomacy | Derwood Bowen | 7 |