Welcome to Space Station Nerva, Marine
Your job is to secure the facility from other hostile military forces through the strategic taking and holding of supply ports. With each supply port that you gain, a reinforcement will be sent to your entry point. Due to the hazardous nature of a boarding actions in deep space, spacesuits will also be issued so you may travel outside the station. Please note - it takes some time to get into or out of your spacesuit. However, to speed the transport of your fellow Marines around the station, you will all be issued with short range transmat units with which you may convoy your troops.
As regular Diplomacy, but with the following changes-
All units are 'Marines'. You will need two types of counters - one representing a Marine, one representing a Marine in a spacesuit.
Marines in spacesuits may not move inside the station, but may attack areas of the station adjacent to space (exactly like navies and coastal regions in normal Diplomacy). If a Marine in a spacesuit enters a station area - the next turn it must either stay where it is, move out into space again, or start changing to a normal Marine. The tubes of the station are small and space is large - a Marine in space may travel across one station section to a space region on the other side as a single move.
All Marines may transmat fellow marines (exactly like navy convoys in normal Diplomacy) whether they are in space or on the station. The only criteria is that all Marines are adjacent and willing (when using allied Marines). A Marine in a spacesuit may only be transmatted to a space region, a Marine without a spacesuit may only be transmatted to a station region
It takes one turn for a Marine to put on a space suit or take one off. Place the Marine counter on it's side to represent that it is changing. If attacked while changing, the Marine counts as whatever it was last turn. A Marine that is changing cannot move, attack or lend support.
A player's "home country" region is now called the entry point. Entry points are the three black circles within the four squares on the outer rim of the station. As with normal Diplomacy, reinforcements appear here an if they are all lost - you get no more reinforcements. Players should start at opposite or equidistant ends from each other.
Orders are written as normal, and players may discuss plans as normal Diplomacy.
I have created two maps, but have not as yet labelled the regions. Grey areas are space, white are station. Black circles are home supply ports, white are neutral.
Word document that generated these maps
New - Now a partially written PHP image generator to draw a map for between 3 and 20 players
The original Diplomacy rules.
The working area for my online game.