Diplomacy (board game)
Diplomacy is a board game. In its standard form, it involves 7 players, each controlling one of the major European powers just before World War I: England, Germany, Italy, France, Russia, Turkey, or Austria.
Game play
The game map divides the land and sea areas into territories. Some land territories, corresponding (roughly) to the more populous cities, are considered "supply centers", which generate military units for players who occupy them. Six of the 7 starting powers has 3 supply centers within their borders, and Russia has 4. There are additional supply centers in most of the smaller countries. Military units are either armies, which can only occupy land territories, and fleets, which can occupy sea territories and coastal land territories.
Players attempt to take over as many "supply centers" as they can. They can take over neutral supply centers, such as in the Balkans or Scandinavia, or they may take over other player's supply centers. If a player takes over a supply center, they get to build a new unit in one of their home territories. Players may not maintain more units than they occupy supply centers. A player wins the game by taking more than half of the supply centers on the map.
Game mechanics
Each player begins with two armies and one fleet, except England and Russia - England starts with two fleets and one army, Russia starts with two of each. Play is turn-based, and proceeds in two stages: negotiation and movement. Players negotiate with each other over their proposed movements, then each secretly write down their "orders" - the movements they attempt to make, and submit them to a player (or non-player) who opens them all simultaneously, and determines the outcomes.
Possible orders for a unit are to hold (not move), move to an adjacent territory, support another unit's attempt to move, or, for fleets, to transport an army unit across water. If a unit attempts to move into a territory occupied by another unit, the move fails, unless the moving unit is supported by more units than the unit currently occupying the territory. If two units both attempt to move into a vacant territory, the unit with the most supporting units succeeds; if the amount of support is equal, both fail. If a unit which has been ordered to support another unit's move is subject to another unit attempting to move into its territory, it is unable to provide support.
After all "battles" are resolved, and all orders executed, any player who has increased the number of supply centers he occupies may build new units in his home territories; any player who ends a turn with more units than supply centers must remove units until there is no excess.
The game mechanics are very simple, and thus the "negotiation" phase is where the game reaches its greatest complexity. Negotiations may be carried on in secret or openly. Promises and agreements are not binding, except as a player may fear the consequences of reneging on an agreement. Each of the players has to work out agreements with other players to obtain more than minimal success, but must also weigh the trustworthiness of their agreements' counterparties and the risk of being "backstabbed" each turn.
Alternate maps
There are many alternate maps and settings for the game of diplomacy. The most popular is the so-called "Youngstown" map, which keeps the European powers in similar positions, but adds the continent of Asia.