Game supported Alliances.
You can invite a race to become an ally. The idea here is that you can then allocate systems to allies - i.e. joint defence to reduce the overhead of protecting a large group of systems. There are two levels.

Combat Ally
One is an ally in combat - you get no DL from them and you get a shared turn report. ie within systems you will see all his ships/drones/mines as well as your own.

Empire
You get the benefits of the above. You also get one race who is the empire creator, and he can invite races to join the empire. The members of the empire can donate credits to each other. They also get the Combat Ally benefits.

Empire-mates should be able to share Current networks.


the structure you discribe sounds very lord->vassal... would it be possible to allow vassals to create their own, subsidiary, empires (the vassal of my vassal is, indirectly, my vassal- but owes loyalty and fealty to me only through their direct lords continued loyalty.)

The idea of an empire owner is simply that someone has to do the inviting.

It is not meant to impose vassel status. There is no tribute etc. It's simply a club of mutual defense where you can freely donate funds to others within the club.

Could share currents I guess.