PlayDiplomacy implementation of Diplomacy rules

[super_dipsy]

This post replicates the information provided in the Site Rules section, but it seems appropriate to put it here too.

The site policy is to use AH 2000 4th Edition as the base set of rules for online Diplomacy play. However, there are places where we deviate in some fashion from the 4th Edition rules:
- When the written rules are silent
- When the written rules are ambiguous
- When the written rules cannot be implemented
- When the written rules do not fit with online play
- When our site members demand deviations

It may surprise some to realize that there are any examples of the first 3 categories, but sadly the later sets of rules have been written with little thought and attention to detail. However, since these are the 'official' rules we follow them as much as possible.

Here is a list of deviations
1. Country selection; random is required but we actually allow FCFS or Preferences too (Member-driven)
2. Draws:
2a. DIAS is required, but we only offer DIAS as an option (Member_driven)
2b. The rules (DIAS) say only countries with units on the board share the draw; we include countries with SCs but no units (Common sense)
2c. Draws that have not been rejected are considered approved when all countries that still have SCs and/or units have approved (Common sense)
3. Illegal orders; legality is determined at the point in time based on all possible order combinations. Illegal orders are replaced with Hold orders BEFORE adjudication (Rules unclear)
4. Timings / negotiations; the rules specify time periods for order submission and that negotiations are not allowed in Retreat/Build phases. We do not do this (online play)
5. The intention of a rule can be used by the GM to determine the rule even if badly written. We go with exact order requirements, no interpretation (online play)
6. We regard a convoyed army as having come from the start location of the army (Rules silent)
7. We implement the Szykman resolution to paradoxes (Rules silent or cannot be implemented as written)
(Szykman resolution says that within the CORE paradox only, all convoys are cancelled)
8.We implement automatic disbands by calculating distance as the minimum number of moves for the unit in question to return to a home SC, and counting a potential convoy route as one move per sea square (Rules ambigious / silent)
9.We implement 'via convoy' which overrides the land route (rules unclear / silent)
10. We allow a deadlock resolution to close a game as a draw (online play / member-driven)
11.The rules require that in a 2-player game Italy is assigned to one of the two players at the end of the first year on a coin toss. We leave it in CD for the whole game (member-driven)