Satellite Empires

The idea here is that instead of being eliminated, an empire could choose to surrender and become a satellite empire of another empire.  In practice, this would be similar to an alliance except the surrendering empire can no longer win the game on their own, and only the winner would (normally) be allowed to disolve the satellite agreement.  The key thing is the empire would continue as a separate entity, but be subordinate to the empire to which they surrendered.

If I remember correctly, the old Alpha Centauri game had this feature.  Sometimes when you were winning against another faction, especially in the early game, I think, that faction would offer to join you instead of being eliminated.

Some thoughts on how this could be implemented (from the user interface side):

• There should still be a relationship bar between the two empires.
• The relationship should be reset to neutral when the satellite agreement comes into effect.
• If the relationship bar reaches maximum happiness, then the client empire could be absorbed (non-violently) into the primary empire (in multi-player the player would have to agree this).
• If the relationship bar reaches minimum happiness, then the client empire would be given the option of revolting against the primary empire and becoming independent again (it should cost a lot of influence to do it).
• The primary empire could set a "tax rate" on the satellite empire, default tax rate is neutral (maybe 20% of client's net dust per turn), lowering the rate would increase the client empire happiness and increasing it would lower the client empire happiness.
• The primary empire would be able to make demands on the satellite empire, like asking for technology, resources, dust, planets, or even attacking another empire.  Each demand would lower the relationship.  Conversely the primary empire could also give the client empire technology, resources, dust and planets which would increase the relationship.
• The primary empire should probably be able to give a general direction to the satellite empire (for example: build ships for war, terraform your planets, build your economy, research technology, etc)
• When an empire can make demands of another empire because of war momentum they should be able to demand the other empire become a satellite empire if they are winning, or offer to become a satellite empire if they are losing.