Diplomacy is a board game, war game, and strategy game set in Europe in the era before the beginning of World War I. From two to seven may play, but the game dynamics are best with seven. Each player controls the armed forces of one of the pre-WWI European powers: England, France, Germany, Italy, Austria-Hungary, Russia, and Turkey. Players move armies and fleets across the board, forging and breaking alliances along the way. The game ends by agreement among all surviving players, or when one player wins by gaining control of more than half of the continent.

Diplomacy is a registered trademark of Avalon Hill.

Equipment
Each player begins the game with three units (armies and fleets) of their own color, except Russia, which has four units, two armies and two fleets. The board is a map of Europe showing political boundaries as they existed at

the beginning of the 20th century, divided into fifty-six land regions and nineteen sea regions. Only one unit at a time may occupy a region.

Thirty-four of the land regions contain supply centers, that is, major centers of industry or commerce. Victory is achieved by controlling eighteen of the thirty-four supply centers. For each supply center a player controls, he or she may build and maintain one unit on the board. (If a player is entitled to build a unit for which there is no available game piece, any marker may substitute.)


The play
The game mechanics are relatively simple. Unlike in similar games, players do not individually take turns. Instead, before each move, there is a negotiation period in which the players entice, wheedle, bluff, cajole, and threaten each other in an attempt to form favorable partnerships. Secret negotiations and secret agreements are explicitly allowed, but no agreements of any kind are enforceable. After the negotiation period is over, players secretly write orders for each unit and these orders are revealed simultaneously. All moves are then simultaneously executed and any conflicts are resolved as described below.

On each turn, each unit may hold in place or move to an adjacent region, with the restriction that armies may only occupy land regions, and fleets may only occupy sea regions and land regions which border the sea. A unit which holds in place may additionally support an action in a region to which it could have moved. Finally, a fleet which holds in place may (in lieu of supporting an action) convoy an army across a sea region from one land region to another.

When two units attempt to occupy the same region, the one with more support wins. There are no dice involved. The greatest concentration of force is always victorious; if the forces are equal a standoff results and the units remain in their original positions. If a supporting unit is attacked (except by the unit against which the support is directed), the support is nullified, which allows units to affect the outcome of conflicts in regions not directly adjacent.

Occasionally these conceptually simple rules result in situations which are difficult to adjudicate, or even paradoxical. Therefore the official rules contain comprehensive details and examples. Also, one person may be designated as Game Master to execute moves and adjudicate disputes, although this is rarely necessary, either in friendly games or in tournaments.

The turns are designated alternately as Spring and Fall moves, by convention beginning in the year 1901. (The beginning boundaries of the great powers on the Diplomacy map are from 1914, not 1901, but numbering the years that way makes it easier to count the turns.) Supply centers do not change hands in the Spring. After each Fall move, occupied supply centers become owned by the occupying player. At that point players with fewer supply centers than units on the board must disband units, while players with more supply centers than units on the board are entitled to build units.

Strategy
Because numerical superiority is crucial to success, alliances are vital in Diplomacy. Each country is initially roughly equal in strength, so it is very difficult to gain territory except by attacking with the support of a neighbor. The excitement of the game is less in the tactics than in negotiation, coalition-building, and intrigue. Each player's social and interpersonal skills are at least as important to the game as the player's strategic abilities.

Diplomacy commands a respect among aficionados of multiplayer games similar to the respect accorded to chess among two-player games. Most multi-player games can't help but involve coalition-building to some degree, but only in Diplomacy is the negotiation so critical and so multi-faceted. The game can't be won by going it alone, except in a last mad dash of aggression from a strong position. In the mean time one makes compromises and promises to one's allies while spreading fear and misinformation among one's enemies. And the attacking of one's allies (or the "stab") has a central role in the culture of Diplomacy. A stab can be crucial to victory, but may have negative repercussions in interpersonal relations.

All of the countries on the map have a real chance for success if played properly. Each power requires a different style of play. Italy and Austria-Hungary are often thought to be the weakest as they have many neighbors and can be eliminated early, but if they survive the starting phase of the game, their central position can be a great advantage. England and Turkey are generally reckoned to be the easiest to defend. Under Calhamer scoring (where an outright victory is worth one point and participants in a draw split the point equally) Russia and France typically score the most points, Italy and Austria-Hungary the fewest.

There is a natural buffer of spaces without supply centers between the western and eastern halves of the board. Therefore the first few turns of a game usually break down into fighting amongst the western powers (England, France, Germany) and eastern powers (Russia, Austria-Hungary, Turkey) for dominance in their areas followed by a break out based on the results. Italy is a wild card with a relatively weak position, though if it commits to an alliance in either of the two threesomes, the alliance can be pivotal.

One fascinating aspect of Diplomacy is that in many circles cheating is not only allowed, but also actively encouraged. Players are allowed and expected to move pieces between turns, add extra armies, listen in to private conversations, change other players' written move orders and just about anything else they can get away with. In tournament play, however, these forms of cheating are generally prohibited, leaving only the lying and backstabbing which is prevalent wherever Diplomacy is played.


Variants
Fans of the game have created a myriad of variants, using altered rules on the standard map, standard rules on a different map, or both. An index of over a thousand variants is available at the Diplomacy Variant Bank web site (see External links, below).


Where to play
Unfortunately, it is difficult to organize a full face-to-face game. There must be exactly seven players, and with six or fewer the game may become stagnant and predictable. Also, there is no set time for the game to finish. Tournament games among experts have lasted twelve hours, but even typical games will last four hours or more. To overcome the difficulty of assembling enough players for a sufficiently large block of time, a vibrant play-by-mail game community has developed, using either humans to adjudicate the turns e.g. Redscape or automatic adjudicators e.g. njudge. A great way to get into a game is via the queues available via the Diplomacy Online Resources page or the New Game Openingsvia the Redscape Forum. A web interface is in development, but there are already many excellent tools to help assist play, such as [floc.net] game pages and DipTool.

A popular web based game place is the DpJudge which hosts several Diplomacy games, and sports a slick web front-end for both players and game masters in play by email games on a number of servers. The easy to use web interface will let you list available games, login as a power in a game, enter move orders, view map status and send more or less diplomatic messages to the other players in a game.

njudge and DpJudge game results are used to create JDPR, the Judge Diplomacy Player Ranking system. This is maintained by Doug Massey, one of the true celebrities of the hobby.

BOUNCED provides a noticeably slicker, entirely web-based approach, with a similar interface.

Diplomacy.ca has been running online Diplomacy via a BBS since 1985 and as a web site since 1999.

Despite the length of games, there are those that organize ad-hoc games, and there are also various clubs that have annual tournaments, as well as the World Diplomacy Championship (WDC), played once a year in different places in the world, at which the Diplomacy World Champion is crowned.

Diplomacy is sometimes played in high school history classes because of its realistic emulation of events and diplomacy between nations. It helps students better understand the politics involved in World War I and World War II.


Comparison with other war games
Diplomacy differs from the majority of war games in several ways:

Unit movement is simultaneous, not turn-based - all players secretly write down their moves during a negotiation period, and then all moves are revealed and put into effect simultaneously. 
Social interaction and interpersonal skills make up an essential part of the game play. 
The rules that simulate combat are strategic, abstract, and simple, not tactical, realistic, or complex. 
Combat resolution contains no element of randomness -- no dice are rolled and no cards are shuffled. (Individual players may attempt to incorporate randomness into their choice of moves, as a strategy to prevent their opponents from outguessing them, a strategy suggested by game theory.) 

History
Diplomacy was created by Allan B. Calhamer in 1954 and first released commercially in 1959. It has been published since then by Games Research, Avalon Hill, and Hasbro.

Since the 1960s, Diplomacy has been played by mail through fanzines. The play-by-mail hobby started in 1963 at virtually the same time by John Boardman in New York and Conrad von Metzke in San Diego independently without either one knowing what the other was doing at the time. Because of this it is truly impossible to know for certain which one came up with the idea first although Boardman is often given credit as the founder of the play-by-mail hobby. More recently, it has become popularly played through e-mail, adjudicated by computer. Also many a game is played online with a human game master.

Diplomacy was John F. Kennedy's and, supposedly, Henry Kissinger's favorite game.


Adaptation
Hasbro released a computer game version of Diplomacy in 1999, without much critical or commercial success. Paradox Interactive released a new computer version in 2005.