Email Diplomacy, or Play-by-Email (PBEM), is the online manifestation of Diplomacy, a board game in which seven players each control one of the major European powers of 1914, and fight for control of Europe.
The 7 players communicate primarily by Email, although Instant Messengers, Message Boards, or other online communication tools can be utilized as well. A Game Master (GM) runs the game, and provides a central point of contact and administration.
Email Diplomacy is popular due to the difficulty in playing the game face-to-face. Email games commonly last 6 months to a year, tho shorter or longer games can occur as well.