Something I wish I'd known - unit production can be lost

[Tampico]

Made two related and very painful early game mistakes that I wanted to warn those about who don't know, wasted about 25 turns of production across my three fledgling cities:

1. If you have saved production but are not actively working on a unit on the turn you discover the upgraded unit technology, you will lose all your saved production. Thought I was being crafty and banking some production while I had my +50% production card, but I was wrong.
   
2. This one is more of an edge case, but if you need to create a unit for a eureka, you cannot create two of the old unit on the same turn and then pay to upgrade them - the game processes one of them, gives you the eureka, and then converts the production on the other in-process unit to the upgraded version. Not sure if this can happen for anything other than the three archers needed for the crossbowman eureka, but it sure can happen for that one

Be careful out there my friends, don't waste your production kids!

 

[Tabarnak]

Worse, you see that you need 2 more turns to complete a tech and you have 1 turn left to finish your unit from a city. Then bang! Science gets higher and you actually finish the tech in 1 turn, forcing you to finish the unit with production. Can happen at online speed more often than any other speeds.

That said, i like to spam units of a kind to reduce instantly my bank of niter or iron so you can build/buy cheaper units from some remaining cities, also giving a chance to use your gold for upgrades of these same units.

 

[Lily_Lancer]

1：It seems that those productions are not lost but only "not transferred" to the new unit. If due to some reason (e.g. lack of resource for new units) you're allowed to produce those old units again those productions seem still there.

 

[Minou]

Lily is correct that the production should be passed on - e.g. if you have 10 hammers in a Slinger that is being built and then discover Archery, you will then have 10 hammers of progress in an Archer.

However I believe progress is lost if the unit leaves the queue. Let’s say you have 10 hammers in the Slinger, pause it to start a Monument, and then discover Archery. Last time I checked, the Slinger can no longer be built but no progress will be given to an Archer.

A different case happens with some buildings. If you start an Art Museum and swap to an Archaeology Museum, all progress in the Art museum will be lost. I assume the same is true with pairs like Barracks and Stable, though this is very minor as I doubt most people change their mind once they start one or the other.

I am not sure if things vary if you use the multi-queue.

 

[AsH2]

I think it's hard to track because some GUI hardly updates during a turn, but you use mods that take care of it?