Let me preface this with the statement that I absolutely love Galactic Civilizations, I've been a fan of drengin.net games (now totalgaming.net games), and I am completely impressed with Galactic Civilizations II
Now this is how I believe multiplayer could work:
1. Make it only available to a LAN and/or TCP/IP connection
a. with this option in place, massive online lobbies won't need to be created nor maintained
b. you would generally play multiplayer only with your friends (ie people you trust giving certain information to)
i. Any connection problems would be able to be talked about via a phone call
2. Set an option at the beginning of each multiplayer game for a set amount of time per turn
a. this way, game times won't reach into the stratosphere
b. this could be any amount of time you want
c. "turn time" could not be built up/ "turn time" remains constant
3. "Game time" is not nessecarily linked to "Turn time"
a. each player could work on things that do not require "movement" during the other player's turn
i. ship building
ii. tax increases/decreases
iii. decisions on what to build
iv. decisions on what to research
v. decisions on where to go
vi. etc.
b. however certain items would be restricted to actual "turns"
i. diplomacy
ii. movement
c. certain actions could include two players at once
i. invasions
ii. united planets
iii. diplomacy (see below)
iv. combat
4. There would be an option to "end turn" just as in the main game
a. again, this is to limit game length from days long to hours long
5. Certain limits would be recommended for brevity in game length (albeit not required)
a. Galaxy Size
b. Number of computer players
c. Number of human players
d. Lessened victory conditions
e. Game Pace
i. Amount of time for things to be built, researched, etc.
6. Diplomacy would be handled the same with computer players, although different with human players
a. With human players, one player within his turn would "message" the player with a proposed trade
b. Although not in his "diplomacy time" (see above), this player would be able to make counter demands/ accept the trade
c. If either player involved in the trade wish to "discuss" the trade, a "discuss" option would be available
i. this would bring both players to a specific chat/lobby area, where they could formulate a bargain.
ii. this would not count towards "turn time"
7. Game balancing features would be put in place
a. "First turn" would be decided upon a dice roll
b. Handicaps could be put in place to limit/hinder the economy of a race, just as in single player games
8. At any point, this game would be able to be saved and downloaded onto each party's computer, and then reloaded at any time wished
commenting/discussion is encouraged!