by Adrien Baird and Steve Doubleday
ID (Intimate Diplomacy) is a two-player variant. Each player controls one country (his "Home" country) for the entire game. The remaining five countries are known as "mercenaries".
1. The official rules of Diplomacy apply except where amended below.
2. To determine home countries, each player submits a preference list of seven countries. If their first choices are different, both players get their first choice. If their first choices are the same, but their second choices are different, then both players get their second choice. If the second choices are identical then each gets their third choice etc. If both preference lists are identical then the players draw lots with the winner getting their first choice and the loser their second choice.
3. Control of the five mercenary countries is determined each game year by bids. The bidding seasons occur before Spring 1901, and thereafter between each Winter and Spring season. Bids are written down and both players reveal them simultaneously. The highest bidder for each country has the size of their bid deducted from their reserve and gains control of that country for the following year --- including the winter adjustments.
4. Credits used for bidding are awarded following each Fall season. Each player is given one credit for each SC owned by his home country. (E.g., If your home country controls 10 SCs, 10 credits are added to your credit balance.) At the start of the game, countries have the following credit levels: E, F, R & T are given 20 credits, G 22, A & I 24. The difference in starting credits is to even out the relative strengths of the countries.
5. Players are permitted to bid more than their credit will cover. However, if a player's successfully bids more credits than they hold, they lose all their reserve and their opponent then gains control of all countries they bid for at half price, rounded up.
6. When bids for a country are equal, neither player controls it, and it is treated as if in Anarchy for the year.
7. Play is carried out exactly as in regular Diplomacy with each player submitting orders and retreats for the countries which they control. In the winter season, all builds due to neutral countries must be taken where they are possible. The sequence of play during one game-year is Bids, Spring moves and retreats, Autumn moves and retreats, Winter builds and disbandments.
8. Mercenary Builds: If the player controlling a Mercenary country fails to order builds which that country is due, the GM will builds armies alphabetically in home centres (fleets for England).
9. Victory Criterion: The game ends when one player occupies one of their opponents home centres with one of their home country's units in any season. If this happens to both players simultaneously, then the player occupying the most home SCs of his opponent wins, with the exception that occupying 4 Russian home centres counts as no better than owning 3. If a tie remains, the game is won by the player with the largest credit balance (counting credits won during the season in which the home centres were invaded). If a tie still remains, the game continues until the next Fall, when all of the above are reconsidered.
10. A game may develop into a stalemate situation once all neutral countries have been eliminated with neither player being able to break through a defensive line to meet the standard victory conditions. In this case the winner is the player with the most supply centres. Note that unlike Diplomacy, a game does not end just because one country reaches 18 Supply centres.