But that doesn't reflect MP at all.
that's because I never play MP and don't know what I'm talking about

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My input was only designed to suggest a little "out of the box" thinking.
Maybe have a 8 player FFA Pangea game. Where the first 8 players choose their civs. Then repeat this 3 times, but not allowing the same civ/leader to be used twice. In effect you would have the 8 best civs against each other, then the 9-16th best civs against each other ect...
I still think that the only way to really get players to talk about is to make it a succession game. Maybe with only 3 players per civ? That would still require 24 people, but it should be doable.
I don't want to sound mean, but this doesn't look very realistic.
The discussion part should be taken out of the game mostly (= no day by day reports, only a final report), or it will take a "SGotM" like organization to make it possible.
8 players only sounds good, though.
And why limit ourselves to 3 games? We could repeat this on different settings and maps!
sure, if you manage to find a team and if the first game turns out good, you'll be able to do others.
Let's look at the practical side :
- no time limit for turns (or a large time limit, something like 15 or 30 minutes to allow screenshots and notes => very long sessions, even for 40 turns. Going down to 10 turns may be good, but you're not going to finish a game in a week. let's assume 100 turns for a quick game (which is fast in SP, but from what I heard, this could be long enough for a MP), this leads to 10 sessions, 2 hours long.
- planning sessions mandatory (time zone issues + RL issues)
- some diplomacy could be done in between sessions, via email or PMs. This could lead to an interesting read

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Just trying to help, I have no intention in participating.