How to fix the problem of promotions become useless when upgrading to a diff. type

Problem:

For example, when you upgrade a Horse Archer to a Knight the ranged promotions Accuracy and Barrage become useless. Or when you upgrade a Horseman into a Camel Archer then Shock and Drill become useless. This has bothered me since day 1.

The units that experience changes in unit type (e.g. Ranged to Melee, Melee to Ranged, etc) and must deal with this problem are:

* Chariot archer to Knight (Ranged to Melee)
* Hunnic Battering Ram to Trebuchet (Melee to Siege)
* Hunnic Horse archer to Knight (Ranged to Melee)
* Egyptian War chariot to Knight (Ranged to Melee)
* Indian War elephant to Knight (Ranged to Melee)
* Assyrian Siege tower to Trebuchet (Melee to Siege)
* Horseman to Mongolian Keshik (Melee to Ranged)
* Horseman to Arabian Camel Archer (Melee to Ranged)
* Arabian Camel archer to Cavalry (Ranged to Melee)
* Mongolian Keshik to Cavalry (Ranged to Melee)
* And a whole mess of issues with the spearman line of units (affecting everyone, including civs with unique spearman, pikeman and lancer units)

This problem (or feature?) affects every single civ in the game due to chariot archers upgrading into knights and the entire spearman line of units going through many unit-type changes throughout the game. And when it comes to unique units, it affects about 13 or so civs.

I personally think it's a big problem; for instance, chariot archers are a great unit but many people are reluctant to use them because most of their promotions will become useless once they're upgraded. This is a nuisance that affects every single civ in the game, some more than others (i.e. the ones with unique units that change unit-type).

Solution:

My solution is to give each Great General a one-time use ability to 'Reassign Promotions' or 'Retrain Units' or whatever name you please. Using this ability will consume the Great General and causes all surrounding land units (6 tiles total) and the unit that is on the same tile as the Great General to remove all current promotions while retaining all of their experience points, allowing you to choose as many promotions (of the current unit-type only) as you are able to, on the spot. On-the-spot healing is not available, and this does not remove unique-unit promotions that are normally retained through upgrades such as the ones listed here.

* Perhaps make it so that this ability can only be used during peacetime to prevent potential exploits or problems during combat. Maybe make it work only when your GG is inside your own borders.

* This does not work for air units because it's not necessary, and it would make every single stacked air unit in a city reset their promotions leading to a mess.

* Maybe Great Admirals can have a similar ability that works with sea-based units.

This ability is an option, so if you don't want to reset your promotions then you don't have to. For instance, if you have a scout-turned-archer that has Survivalism 3 then you probably don't want to reset your promotions.

 

Is this a widely-perceived problem? You have to imagine the designers had something in mind - I do remember one of the early walkthroughs saying that in Civ 5 promotions were intended to come rapidly and in good quantities so that e.g. a) you would use them mainly for immediate impact rather than thinking too long term, and b) it would often be a reasonable use of a promo to heal the unit (i.e. effectively just throw the promo away )

Incidentally I'm with you about the desirability of long-term thinking about promotions. I think the promotions sub-game could be much more interesting and have more strategic choice about it But I would look at redesigning the unit categories and whole promo system to make it more interesting rather than putting a sticking plaster on the existing one

 

Personally, I really like Civ 5's experience and promotion mechanics and don't think an overhaul is necessary. I just don't like it when some of my promotions become obsolete when upgrading certain units.

 

I'm of the opposite opinion. I think the whole idea of upgrades could go away. It would make promotions both better and worse, but more importantly it would make promotion / XP granting buildings more important.

 

There's also the possibility of stacking promotion types: if you upgrade a Keshik with Logistics to a Cavalry, you can then give the Cavalry Blitz for 3 attacks in one turn.

Your solution is a lot more convoluted than the one I'm implementing in the next version of my mod (I already programmed it in and everything, though I'll have it toggleable via XML): when a unit is upgraded, all promotions that can be unlocked by leveling up that the original unit had but the new unit could not get are refunded, causing the promotion to not transfer and lowering the amount of levels transferred by 1. Since XP is still transferred over completely, the result is that the game gives you a level up prompt the turn after you upgrade. Everything is automatic, no fiddling with Great General abilities or anything like that. It does generate the possibility of upgrading a unit at a certain time to select insta-heal as one of the refunded promotions, but I don't consider that too big of an issue to really exploit (you are throwing away your chance at a promotion, after all, and you still have to wait a turn before you can promote your upgraded unit, so it's still not an instant insta-heal at will).