Global Diplomacy

A variant of DiplomacyÔ by Eric Pederson (version 0.3c)

This document contains the variant rules only. You must know the standard rules for Diplomacy to play this variant.

The current map is available in the .bmp format: GD_v03.ZIP (29k) or  Map03.bmp (390k)  and .gif format Map03.gif (40k, color) or Map03bw.gif (28k, B&W)

Short cuts for non-initial readings: Support rules Nuclear rules Standard game comparison Q&A

Rule differences between Global Diplomacy and regular Diplomacy

The standard rules of Diplomacy apply (I’m drawing from the 1976 Rulebook), except as noted below. If you are not familiar with the standard  game, first check  The Diplomacy Home Page.  A new map is used. The calendar is four movements (including two builds) per year.

I. Global diplomacy is best played by 6 players – although rules for 2-5 players also exist. Each player represents a Superpower at the dawn of WWIII (fortunately for us, this is not until the early 22nd century): The United States (US), The Russian Federation (RF), The South American Alliance (SA), The European Union (EU), The Greater African Union (GA), and The People’s Republic of Asia (PR).

II. Victory conditions obtain at control of 16 Supply Centers at the end of a building season (Spring or Fall). If fewer than 16 supply centers are left on the map at some point in the game (courtesy of nuclear destruction, see below), the globe is declared uninhabitable and all players lose. If it becomes impossible even in principle for any one player to acquire control of 16 supply centers, the game is immediately declared a draw for all remaining players. At any point in the game, a draw may be declared by unanimous vote by all remaining players. In the unlikely event that two players achieve control of 16 supply centers at the end of the same build season, these two players must decide whether to have the game declared a two-way draw between them or whether to continue play until only one player (who in principle could be a different player than these two) has control of 16 supply centers. If these two players do not agree as to the prefered outcome, the default is for play to continue until only one player has control of 16 supply centers. This rule is iterative.

III. A socially kind option is to agree that play ends at the end of the first year in which one player is eliminated. Victory to the player with the most supply centers at that time. This is not the default and must be agreed upon by all players prior to play.

V. There are 36 supply centers on the board at the beginning of the game. Supply centers may be permanently destroyed by nuclear attack. Any supply center which becomes disconnected from other supply centers through all potential connections of land or sea being destroyed, will disappear in the season following the destruction of the last connecting space. For example, if NIO, KAZ, TIB and SEA are all destroyed by nuclear destruction by season A, and MIE is destroyed in season B, then the supply center in India is removed at the end of season C. In this example, the spaces of PAK and IND may continue to exist (without a supply center in IND) and units may remain there until disbanded.

VI.2. There are four types of units: Armies and Fleets/Navies (both as per the standard game) as well as Air Forces and Nuclear Arsenals. Each superpower is allowed a maximum of five each of armies, navies, and air forces at any one time on the board.

VI.3. There is no fixed starting arrangement. The game begins with a building phase with no prior diplomacy.

VII.1. An air force moves as per an army (one space, on land only) and may be convoyed, but may not convoy other units. An arsenal cannot move (nor retreat).

VII.3.a. There are two canals – the Panama and the Suez. All units may cross over canals from one land area to the another and navies may cross through canals from one coast to the another water space. In other words, they constitute a four-way intersection of land and sea routes. Note that the canals are not spaces in their own right: no unit may occupy them. Spaces on either side of the canals are considered to share a border for purposes of movement. The four coastal spaces which border the canals are considered to have a single coast line. Note that there is no water passage between Papua New Guinea and Queensland, but rather these two land spaces are considered rejoined by low sea water levels (which is admittedly unlikely to be the case in the 22nd century). Note that for game purposes, Indonesia is also considered part of the New Guinea/Australian land mass.

VII.3.b. Mexico, Western Europe, Russia, Papua New Guinea, and Queensland all have two coasts. Naval movement and deployment as per Standard Diplomacy fleet rules.

VII.3.x. There are two spots on the maps which are not spaces and which cannot be occupied or crossed by any units: Lake Victoria in Africa and the Caspian Sea in the Near East.

VII.3.y. Two spaces have seasonally restricted movement into and out of them: Antarctica is restricted to Fall and Winter movement only and the Polar Arctic is restricted to Spring and Summer movement only. Support orders and bomb carrying orders can be followed by units in these spaces in all seasons. Additionally a navy in the Polar Arctic can convoy an army or air force across the Polar Arctic in all seasons.

VII.6. Sequence of play

If play is continuing (no draw or victory condition), the next turn is Winter 2102. And so on…

IX.1. Armies and navies give support as with standard Diplomacy. In addition, air forces may support into a space up to two spaces away using any route. Air forces can support actions on both land and sea. For example, an air force in Tibet may support a hold in or a movement into India or the North Indian Ocean, but not the South Indian Ocean. Support by an air force can apply to any space adjacent to an adjacent space. For non-judge games, it is not necessary to state the intermediate space in an order of support two spaces away. For determining which spaces an air force can support, it does not matter what the status of that intermediate space is. It can be destroyed by nuclear attack (see XII+ below), it can contain any unit, or it can be empty. The only exception, of course, is when a unit in the intermediate space is actually attacking the air force attempting a support order (i.e., cutting support).

While air forces have this extra range in supporting other types of units, they may not receive support themselves. That is, they may not receive support for movement/attack nor for holding – they can never have a strength greater than one unit for any action.

XI. Note that retreat orders are written within the same season as the movement. Accordingly, a unit may not retreat into Antarctica or the Polar Arctic during a season in which it could not move into that space.

XII. Note that air forces cannot do the airborne equivalent of a convoy, though they may themselves be convoyed across bodies of water.

XII+. Nuclear powers.

A superpower may elect to become a nuclear power by ordering all units to hold during one movement turn. During any following build phase (even in later years/seasons), this superpower may elect to build an arsenal as one of the units the superpower would otherwise be allowed to build that season. This may only be done once per "all units hold" order. The arsenal counts towards the total number of units controlled by the superpower and may be disbanded under the same conditions. In principle, it is possible for a superpower to have multiple arsenals (having issued multiple "all units hold" orders), although this is unlikely in practice.

This arsenal unit may never move, retreat, or support. It may only hold, disband (under normal disbanding conditions for all units), bomb, or carry bombs for other units to deliver. It may not share the space with any other unit, nor may it receive support from other units (like airforces). If another unit moves into that space, the arsenal is disbanded (it cannot retreat).

As with convoys, two (or more) units (of any number of superpowers) may carry a single bomb across stretches of spaces – each unit carrying the bomb to a space to which it could give support. As with convoys, two (or more) units (of any number of superpowers) may carry a single bomb across stretches of spaces. To write the order, specify the entire route for the nuclear arsennal, and not just the start and end. The units involved may either specify the entire route or just the link that they are involved in.

To launch a nuclear bomb, the nuclear arsenal either carries a bomb to any adjacent space or to any space adjacent to an adjacent space for another unit to carry the bomb further, or it simply bombs that space directly (eg, arsenal WAF bombs MED).

An example of a bombing chain:
Arsenal West Africa delivers to Israel to Middle East to drop on Tibet
Air force in Israel carries bomb from West Africa to Pakistan to drop on Tibet
Army Pakistan carries bomb from West Africa (via) Israel to drop on Tibet
Or more tersely:
R WAF bomb via ISR via MIE to TIB
AF ISR bomb from WAF via PAK to TIB
A MIE bomb from WAF from ISR to TIB

However, any attack – whether successful or not – on any of the involved units (including on the arsenal itself) will destroy the mission. In the above example, a unit order of "Air Force Saudi Arabia to Israel" will destroy the mission. An order of "Air Force Tibet to Pakistan" will also destroy the mission even though the attack is directed on Tibet. If any unit in a chain fails to carry the bomb (e.g., no correct order written for that unit or the bombing attack is cut), the mission is failed and the bomb does not explode anywhere. Bombs are only "carried" in so far as they are part of a bombing attempt. When bombs are not being dropped, they do not exist except as potentially available from the arsenal on later bombing attempts.

If a nuclear bomb is successfully carried and dropped on a space, that space is destroyed for the remainder of the game. If there is a supply center on that space, that too is destroyed and can no longer be counted towards any player’s count of controlled centers. No unit may ever move or retreat into that space again, although air forces may continue to fly support (or carry more bombs) over it. All bombs are launched simultaneously at the end of the movement phase. Because of this, if two superpowers successfully launch bombs against each other’s arsenal, both spaces (and arsenals) are destroyed. Further, since successfully dropped bombs destroy the space after successful movement but before retreats, a unit might successfully move to a space only to be destroyed along with the space. If a unit attacks a space forcing a disband/retreat of the unit occupying that space and the space is also successfully bombed, both units are destroyed.

XIII.1. Note that control of a supply center is determined by the last occupation of that supply center at the end of a Spring or Fall season.

XIII.2. Note that in this game calendar, building and removing units occurs after the retreat phase and still within the same season as the movement phase they follow.

XIV.2. While the ideal game is played with exactly six players, a perfectly decent game can be played with less using the all-units-hold method of standard Diplomacy in the five and four player versions. As under standard Diplomacy, adjustments and building of units is in accordance with the individual superpower holdings – including the limit of five of each type of unit per superpower.

5 Players: No one plays the European Union (those units hold). The supply centers in Yakutskaya and Scandinavia are eliminated. RF and EU begin with three units. Victory condition obtains at control of 15 supply centers.

4 Players: No one plays the European Union or Africa. The supply centers in Yakutskaya, Scandinavia, and Madagascar are eliminated. RF and EU begin with three units. Victory condition obtains at control of 15 supply centers.

3 Players: North and South America are played by one player; the European Union and the Russian Federation are played by another player; Africa and the People’s Republic of Asia are played by the third player. (Alternatively, each player draws lots to determine which two superpowers he or she will play.) However, the constraint that each of the six superpowers can only have five of each type of unit remains. The supply center in Yakutskaya is eliminated. The Russian Federation begins with only three units; the EU begins with four units. Victory condition at control of 16 supply centers.

2 Players: This is a game of strategy without diplomacy periods, but still with simultaneous orders. One player plays North and South America plus Africa (the naval powers), and the other player plays the European Union, the Russian Federation, and the Peoples Republic of Asia (the Eurasian powers). Alternatively and for a more varied game, each player draws lots to determine which three superpowers he or she will play.

General notes comparing this game with Standard Diplomacy


This variant grew out of Face to Face play around 1980 with various friends. The standard Diplomacy really required seven players and seemed a little too predictable. So I set about to design an alternative game which we could play when someone didn't show up for the seven player standard game and which would be a bit different as well. The primary design goal was to increase strategical and diplomatic complexity, while decreasing the number of players. I wanted to minimally increase the rule complexity as Diplomacy has an elegance of rule structure not found in the war games with which it is often compared. Game balance despite assymetrical positions was also of high importance and I feel that I have been reasonably successful with that. I first took this variant into the PBEM community in 1997. I consider the design near the end of play-testing. The map design may undergo one further change and the nuclear arsenal rules may be tried under one other variation before finalizing the rules. My hope is that if this becomes a popular variant, we can have a single stable set of rules and map.

Having a global board allows for units to wrap around the globe without the artificial constraint of a board "edge" or the oddness of the wrapped board variants. Using Bartholomew’s Nordic Projection allows for minimal distortion of the geographical features (with the obvious exception of the South Pacific).

While finding seven players is a minor problem in PBEM games, it can be difficult in FTF games. Despite one fewer player, the game feels as though there were as many players as in the standard game. Each player is at most three spaces from any other player and must always consider all the other players even for short term planning.

In an effort to maintain the relatively learnable and elegant rules of the standard game, the changes in rules have been minimal. What changes have been made are designed to increase the strategic complexity more than the rule complexity.


No fixed starting arrangement helps each game to be different from the others. While there may still be a favored opening for each player, they become more variable.

Air forces do add some complexity to the rules, but the possibility of distal support greatly loosens up play in the mid- and late game. Not allowing air forces to be supported keeps the relative unit strengths roughly balanced. (The annoying bi-coastal spaces are to help decrease the value of fleets beyond the early game as well.)

Because each superpower is limited to five of each type of unit, as a player nears victory, the options become more restricted – requiring careful planning.


I have attempted to improve the balance of power in the game while maintaining asymmetrical characteristics of the various superpowers.

One of the main weaknesses of Diplomacy is that weakened players have little incentive (beyond honor and commitment) to stay in the game. The problem is slightly reduced in Global Diplomacy. I have increased the options of weaker players and decreased the options of the more powerful players. For example, the nuclear option gives weaker players a powerful means to gain allies to help their survival. A nuclear power can also engage in much mischief.

All superpowers are essentially close neighbors of all others. Making early diplomacy with everyone even more vital than with the standard game.

Draws are also discouraged: because of the nature of the global board, stalemate lines seem virtually impossible without nuclear devestation. It may be noble to draw, but that’s not what we sit down to these games for anyway…


May a unit retreat to a space with an arsenal?

No. An arsenal counts as a unit. Therefore the space is occupied and unavailable for retreat.

Can a fleet in Pol offer support for an action (eg. GRE) during the cold seasons?

Yes. And ditto for an air force or fleet in ANT. This is a slight rewriting of the dip rule: "[The space receiving support] must be one to which the supporting unit could have moved if not opposed by other units..." to: "The space receiving support must be one to which the supporting unit could have moved (in a season when movement to that space is allowed) if not opposed by other units..."

Can this support be cut?

The support cannot be cut during the cold seasons (Fall/Winter for POL; Spr/Sum for ANT). In terms of design, this feature of POL and ANT increases the advantage of putting a unit in an otherwise disadvantaged spot. Reminder that convoys can also be made across POL during all seasons.

Does the arsenal have to be specified with the orders calling for all units to hold or do I get to wait to see the movement results before deciding where the arsenal will be?

The arsenal build order can be made in any! build period subsequent to the "all units hold" order when you are entitled to build a unit. It can be years later.

The "all units hold" order announces that your power is "a screw's turn away" from developing nuclear capabilities. When -- or even if -- you choose to build an arsenal is at your later discretion.

When do the nukes resolve? before or after movement? If a unit holds in a space under nuclear attack I suspect it gets destroyed without a retreat. What if the unit moved out of the nuclear space? What if the unit moved into the space on the same turn it gets nuked?

Spaces are destroyed after movement, before retreats. Your suspicion is correct: a unit in that space after movement, but before retreat disappears. A unit can leave and enter the "nuked" space during the same movement turn as the bombing orders. If the bombing is successful, the unit entering the nuked space will be destroyed. The unit having just left will feel fortunate.

If any of the orders fail (i.e., are cut just as a supporting action by the same unit would be cut), then no bomb explodes anywhere - the arsenal remains viable for subsequent movement order seasons.

Write bombing orders as per the following examples.

Example 1

(OK, with no other relevant orders)

Arsenal RUS bomb SCA

Example 2

(OK, with no other relevant orders)

Arsenal SUS bomb via NAT SAH EGY to SIO
N NAT carry bomb from SUS via SAH

A SAH carry bomb from NAT via EGY
AF EGY drop bomb from SAH to SIO

Example 3

(Same as Example 2, but it fails because of a "cutting".)

Arsenal SUS bomb via NAT SAH EGY to SIO
N NAT carry bomb from SUS via SAH

A SAH carry bomb from NAT via EGY
AF EGY drop bomb from SAH to SIO


NB: in example 3, the N in NAT is not dislodged (as would be necessary for breaking a convoy order).

Changes from previous versions

Changes from 0.2

Nuclear arsenals become just another type of unit -- essentially a bomb carrying, non-movable air force. This should slightly increase the cost of creating and maintaining a nuclear arsenal and reduce the likelihood of rogue minor powers forcing draws.

Supply centers which are completely cut off from other supply centers by nuclear devestation are removed.

Iceland removed as a playing space.

Non-playing space of the Great Lakes has been removed.

Supply center moved from EUS to SUS.

URA border with WSI now touches EAR rather the POL.

Victory conditions obtain at the end of any building season as per the standard game; not at the end of a calendar year as per 0.2. This should speed the end game.

Changes from 0.1 to 0.2

Red Sea and Indian Ocean boundaries redrawn. Red Sea becomes NIO; Indian Ocean becomes SIO.

Border between NAT and MAT redrawn to connect with SAH rather than WAF.

North Africa split into SAH and EGY. SC goes with EGY.

Repeated abbreviations repaired. Southern Australia becomes SOZ. Spain becomes SPN.

Supply center moved from ESI to YAK. (Previously the names were also reversed.)

Changes from 0.0 to 0.1

New map projection.

East and West Antarctica merged into ANT.

Siberia split into Eastern and Western halves. SC with ESI.

Limit of 5 of any unit type imposed.

Last modified: 24-Jul-98