Gameplay data
Game: Heroes of Might and Magic 3
Type of game: hotseat
Lenght of game: total of several weeks, but if played non-stop and without interruptions it would take a day or two, I guess.
The average length of combat: at the beginning about 1-2 minutes, later escalating to approx. 10 minutes
The total number of combats: too many, though only 3 were conducted as player vs. player
Players: 3 human players, several computer players.
While at the beginning it was great, later it tended to get a bit boring, due to lenght of the fights (yes, it was interesting for the person actually doing the fighting, but the rest of us sat with nothing to do).
Game: Civilization IV
Type of game: LAN
Lenght of game: approx. 8-10 hours
The average length of combat: irrelevant
The total number of combats: numerous
Players: 2 human, several computers
This time it was much more engaging, as game turns passed quickly.
My conclusion: the fights should be pretty quick (at least in multiplayer). This means that either the player who was fighting a prolonged battle gets less time of "normal" play (the fight would extend to the next turn time a bit) or the battles themselves should be quick, but that would usually mean reducing their strategical complexity (I think this might be a good thing - this is a turn-based strategy - the battle should be won before it even happens with economy, science and tactics on a grand scale, rather than fancy battlefield tactics - that's what RTS's are for. This would also mean that the ship design should be as simple as possible.)
Now, switching to diplomacy:
It's not aviable in any game I know of but I've thought of two diplomacy options that could possibly be used (though it would be a bit hard for AI to evaluate if it should agree or not)
Demands:
- request removal/reduction of military presence in an area (can create DMZs or just notify them you're not comfortable with their fleet next to your border)
- request strenghtening of military presence in an area (most likely when allied with the other side and trying to cut off someone's supply line, reinforcements, or just to create a defence line)
As for diplomacy options from existing games I really liked the idea I first encountered in Civ IV.
Trade:
- request/give access to a resource
It actually made diplomacy worthwile, as those were valuable and easily obtained in large numbers but little variety, which forced players to trade them (first time I opened the diplomacy screen myself in any civilization game). The only problem is I don't think we have any plausable alternative to that... unless it could be done with planet specials (crystals, rare minerals, spice, tydirium?), and some upgradeable ways of harvesting them (1 for just having a colony on the planet, 2 with lvl.1 mine, 3 with lvl.2 mine, and that's it).