I was must suggesting using promotions as a mechanical vehicle in the DLL/XML to allow different modifications to attach to leader units. I did not intend to imply that those promotions would be earnable in any way, just that leaders would get two of them at birth innately. Thus no requirement to engage in combat. The intention in having good combat effects on the leader (though GC mechanics of whatever) is to provide an incentive to risk the leader in combat and thus risk losing your traits. It should be a balanced decision for the player whether it's better to just sit the leader in your capital in safety, or engage in frontline action with him/her, with the optimal choice being situational.
Ok, then I agree completely!
Perhaps they can just age, so they gain 1 xp point per turn and once they reach 200 (200 xp) turns - lets say they die and get replaced. Promotions is another good way to overcome the limitation of the traits xml it seems.
I would NOT want to make xp a measurement of aging because that would be a very good reason to NEVER take your leader to war. BUT we COULD easily establish an 'age' for leader units that counts up every round and establish a mortality length.
Perhaps election cycle periods for democratic nations could work like this: We establish an amount of rounds between election cycles, but the leader doesn't die at the end. A new leader is created when an election decides to replace the current one(if they have a high enough approval rating, they would likely choose to repeat the same leader (perhaps term limits could be introduced...)) The old leader, however, doesn't 'die' but remains on the map as a useful leader while a new one is generated, perhaps with traits the nation thinks it most needs right now. (or we could just make the elections a matter of the player's choice and if he chooses to generate a new leader, he selects initial traits then, or picks from a list of available leaderheads.)
In fact, that could be one of the benefits of democratic nations. Their leaders would not have quite the extended 'lifespan' but they would come into play with more traits, and you'd accumulate a number of leaders in play with each election that replaces the current one. Under a more Monarchy style, you would commonly only get a new leader when the old one dies.
This is not to suggest that a leader who isn't currently the head of the nation's traits would continue to benefit the nation, but I'm kinda liking the idea of giving leaders access to a unique line of 'governing' promos that allow it to, via collection of promotions, improve the functioning of the city or region that they are currently in. They could also be used as 'diplomats' as well. Some of that could tie into DH's diplomacy mods coming up. I realize they're made for barbs but if they could do some cool international stunts, it could be quite helpful.
Another thing this system could open up is other Governing Units. These units could BE the pool from which new leaders are chosen. We could really open these up so that each nation commonly has quite a few of them. When a King dies, it goes to his son, the prince, etc... Princesses would be tradeable for great benefits. Governors could enhance cities in their location until elected as President. Heroes could be considered these kinds of units and held aside for eventual elevation to Leaderhead status. The system could get very interesting.
No, but new ones would be born, and if you have multiple you could choose which one was in charge (and thus which one's traits you get). MAYBE, more advanced civics would allow secondary leaders (regional leaders or something) that means a second leader could have their traits also applied at half value (or some similar mechanic)
I replied to much of this just above I think. Interesting idea to blend in other leaders having some trait impact on the nation even if they aren't currently the leaderhead. hmm...
Would it be possible to make the promotion traits on these leader units only affect the city they are in?
For example:
A) Culture leader is in capital and gives that city a boost to culture. Leaves the city and is out wondering around and there is no culture boost whatsoever. Goes into another city and that city gets a culture boost.
B) Aggressive leader is in city and all units trained there get combat I promotion. Leader leaves the city and any newly trained units do not get it.
Only one leader's promotion trait could affect any individual city at a time.
In principal yes, but quite a bit harder to do (as in more work and more changes)
Again, I kinda replied to this above. It would be very possible to create promotions that allow for regional bonuses that work similar to traits. Maybe the 'traits' of the Governing Unit would be applicable to increasing region sizes (range in plots from the location of the Unit) based on promotions they can achieve that could extend that range. (Perhaps this could somehow also tie into secondary capital buildings too... extending the range of such governing units extensively...)