Feature request: Build obsolete units?

[dobragab]

I have a specific gameplay problem that I'm trying to solve. A config option "allow_building_obsolete_units" would be one, but I'm not sure if it's the best.

During normal gameplay, when I discover Gunpowder, I do NOT build roads to Saltpeter until I discover Cavalry, so I can continue building Pikeman in all occupied cities. Musketman takes forever (twice as long, rightfully so) and Pikeman is just enough for most purposes. Last game, I discovered Saltpeter on a tile with road, and ended up pillaging the road so I can keep building Pikeman.

This also happens with Rifleman and Infantry. I usually discover Replaceable Parts before Nationalism, but then I can't build Rifleman anymore.

Another annoying use case is when a special unit upgrades to a generic unit, which is a downgrade in some respects, so it would be useful to keep building the old one instead:

• Gallic Swordsman is 3.2.2 but Medieval Infantry is slow, 4.2.1, and more expensive (Probably upgrade to Knight instead?)
• Same with Jaguar Warrior and Swordsman
• Legionary is 3.3.1 but Medieval Infantry's defense is weaker, 4.2.1 and more expensive
• Same with Samurai 4.4.2 and Cavalry 6.3.3
• Keshik is 4.2.2 but ignores terrain cost of Hills and Mountains, so they are MUCH faster over hilly terrain than Cavalry 6.3.3

Another interesting use case is when I want to use a special unit to induce Golden Age, but it's already obsolote by the time I get into war, or I can't even build it in its era because I didn't have the resource (e.g. Iron).

These two cases would be solveable using an "allow_building_obsolete_golden_age_units", but that doesn't solve my usual day-to-day base scenario.

Obviously it would be overwhelming to see all obsolete units in the list. I think an array-like config option would solve this, where I could specifically list the units I want to keep building despite being obsolete. An optional value "up to" which unit (e.g. keep building Legionary only up to Guerilla) would be useful, but I think that's solveable with a different upgrade path.

[maxpetul]

Hello and welcome! Actually the game already lets you build golden age triggering units as long as you haven't had a golden age yet. The specific condition for obsolete units is that City::can_build_unit returns false when the exclude_upgradable parameter is true, (the unit type in question can't trigger a golden age or the city owner has already had a golden age), and any unit type later in the upgrade chain can be built by the city. To change how upgrading works, we could set exclude_upgradable to false then reimplement the upgrade condition in mod code.

We could make it so that obsolete units are buildable if they're only one step obsolete, that's kind of a compromise with making all obsolete units buildable. To avoid cluttering up the list of build options, we could have that apply only to certain unit types listed in the config. That's simpler and easier than specifying an "up to" type for each. Another thing we could do is allow the obsolete unit to be buildable as long as it's better in some way than its replacement. That would work for most cases you mentioned but not for keeping pikemen or riflemen around.

[dobragab]

Thanks :)

I didn't know about the specific rule for the golden age triggering units.

The one-step obsolete option sounds promising, I think that's a good compromise.