The TBG-1 political system doesn't scale to infinity. Apart from
the difficulty of getting a majority in a government of unlimited
size, it would be very odd to boldly go when no player has gone
before but always stay within the same national state.
A much more appealing system is to have the players actually build the state, expanding from the starting location by getting more and more aliens to join. This gives an increasing incentive to take political power, but also makes it harder to maintain a stranglehold as the opposition can ignore your votes and go out into the periphery recruiting completely new voters.
Two methods of bringing a new race into the federation/republic/union occur to me: peacefully, by accumulating influence in the majority of their homeworld and colonial constituencies, or aggressively by putting the strongest warship over their homeworld and intimidating them into signing up, rather than just extorting their cash. It would be good to have an interesting mechanism for aliens to leave the state as well.
The other end of the scalability problem is in the officers of the government. Having a single president in supreme command remains fun for arbitrarily large states, but there should be more than four helpers. The natural solution seems to be not skill-based ministers but region-based governors.
In TBG-1 the current presidential duties can be heavy, so it'll be best to give them all to the governors, leaving the president with just the power of appointment. In theory this makes no difference, since the president can always bully the governors into making shop/rogue/judicial decisions and handing over the regional alien reports, but in practice the president probably has no use for this level of control outside their own area (where they can be the self-appointed governor of course). It would work more by patronage, where a friend of the president can get favours from the local governor anywhere via a word from the top.
New presidential powers should focus on things that change the balance of power and wealth between regions, allowing some scope to undermine governors who're using the position as a stepping stone to the next presidency. For this it would be good to have huge slow mechanisms which affect the whole known board, such as invading barbarians/borg/orcs which are too strong for any one region to resist. The tension then is between the (temporarily) safe inner regions wanting to pursue their own goals, and the threatened marches wanting central money and/or big ships to come out and help.
Of course for open-endedness this should follow the Trekky model where each implacable foe becomes an ally in the next series.
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2) Recruiting aliens to the Republic/Federation, comes down to a single measure of how much they like the wider galactic society/state, called cosmopolitanism (for the multitude of puns on its modern usage and both its Greek roots). This number also provides the equivalent of Friendly/Neutral/Hostile settings, meaning aliens who've been treated well by some players are less likely to attack other players, and vice versa.
The cosmo rating is increased by "good" acts such as healing plague, trade, and repairing alien ships (active UI makes it easy to allow repair of modules in other ships, player or alien). It decreases with "bad" acts such as intimidation, pillage and attacking their ships. At some level it makes the aliens join the Republic, and at some lower level it makes them leave again (ie there's room for dirty politics in reducing rivals' votes by bullying their voters into seceding).
There's a weakness in motivation for players to recruit aliens to the state, for all but the most fanatical organisation builders, which is resolved partly by giving status for some of the good (and bad) acts, but mainly by the radical step of maintaining a relationship measure for each combination of player and alien race. This would be impractical in TBG-1's C data structures, but is easy in nesh.
This measure (if not small) heavily modifies the general cosmo rating for direct interactions (ie even the most generally friendly aliens will attack someone who keeps pillaging their colonies), and also as a multiplier on political campaigning (so players with a negative relationship can't campaign at all).
The questions are on what else to use these numbers for.
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Main topic: TBG-1 has had several rounds of suggestions to make alien behaviour more realistic, always rejected with the argument against making them into badly implemented players, since we have plenty of those already. But there's another dimension of more complex alien behaviour, where it's used to reflect the actions of players, making _those_ more meaningful.
Building on the cosmopolitanism (liking for the rest of the universe) and player-specific liking ratings discussed earlier, add different classes of alien ship based on, and modifying, net likings. Specifically, have aliens configure their ships according to their cosmopolitanism, with slow migration between types as this changes, and have the ships' interaction with players depend on their liking modified by their class.
The classes include:
Navy: high enough cosmopolitanism for the race to join the Republic means they'll put their naval ships into the Regional Navy, under some sort of control of the local Governor player.
Trader: low and positive cosmo produces ships with cargo and few weapons. They regard player ships they like as protectors from pirates and will give them cargo gifts, at the cost of reducing liking.
Fortress: low and negative cosmo makes the race produce stationary kamikaze warships at their homeworld, discouraging any access to their system by attacking anyone they have negative net liking for.
Pirate: high negative cosmo produces warships which actively go out making trouble for anyone with negative net liking (which with the high negative cosmo will tend to be everyone)
So there are many ways players can affect their environment by influencing aliens, for examples:
Established players might create a Safe Haven around the starting area by making the local aliens friendly, which would be enormously better than having rules to protect new starters until they venture out.
The TBG-1 ideas of Good/Neutral/Hostile aliens emerges from simpler rules.
Slightly troublesome aliens who block tbeir homeworld to you can be dealt with either with a carrot - make them friendly enough to change into traders - or with a stick - abuse them so much that they switch from defence to terrorism, ie they abandon their homeworld and send out pirates to attack mostly other people.
Trader races can usefully be farmed by players strong enough to protect them: threaten other players into not doing things that reduce their cosmo rating (pillage, intimidation, attacking ships, selling their colonies contraband etc.) and collect gift cargo on each meeting.
Races who are just too offensive can be forcefully dealt with using a variant of the intimidate option: direct intervention in their government. Ie the most powerful ship over the homeworld can increase the race's cosmo rating instead of intimidating for loot (which decreases cosmo rating) by what we used to call gunboat diplomacy, but now seem to know as regime change.
Change of ship type by mutation is slow to follow cosmo changes, so impatient players might speed it up by direct action. Eg make the race generally more friendly and then blow up the die-hard pirates so they're replaced with new traders.
If enemy players are doing well out of good relations with aliens who like them (but don't like you), turn those aliens hostile to everyone by attacking them until they leave the Republic and turn into pirates. Then they still won't like you but will be distracted by not liking anyone else either.
Left over questions:
Should the ship classes be in this order, and should there be more classes?
Is a single liking measure, with variable contributions from three separate ratings, enough to produce all the interesting cases?
What exactly can the Regional Governor do with their Navy? (examples include summoning to the Governor's own position, where each appears with a chance related to their cosmo rating, and maintaining a Most Wanted list of player ships to be attacked on sight)