How to modernize units?

[Spieluin]

In Civ 5 one was able to modernize units, e.g. warriors, to the next higher or better unit when I have successfully researched the technology. How does this work in Civ 6?

[gimmethegepgun]

Once an appropriate unit is researched a button appears on the hotbar when selecting the unit to upgrade them for gold. If they're in your territory (or the territory of an ally/suzerain city state) and you have at least 1 of whatever strategic resource the unit may require then you can upgrade them.

[Exemplar]

Much the same. Unit must be in friendly territory, there is a gold cost (halved with policy from mercenaries civic). If the unit to which you're upgrading (as warrior to swordsman) requires strategic resource (as iron), you must have 1 such resource. If the unit is a UU (unique unit as legion for Rome is replacement of swordsman) it does not require a strategic resource.

Strategic resources are not expended in this manner. 1 iron is 1 iron as long as your mine isn't pillaged and you don't trade it away.

Constructing new units (or buying them outright) which require strategic resource necessitates 2 such resource (2 iron to make a swordsman) unless the city has an encampment in which case only 1 is necessary.

Units which require strategic resource cannot heal if you do not have at least 1 of that resource. So, for example, if your great admiral perk spawns a free ironclad, while it's really strong and keen, even in friendly territory it cannot heal until you have 1 coal.

The exception, of course, is pillaging appropriate improvements which restore health. Pillaging a farm will heal your swordsman even if you have no iron, or pillaging a fishing boat will heal your ironclad even if you don't have coal.

[Spieluin]

Ah okay, thank you two. Then I probably don't have researched the appropriate technology yet :-)

[solidap]

Whenever I'm sure I can upgrade a unit and the option is greyed out its always because I forget I'm not in friendly territory. So make suyre you check that as well

[Spieluin]

Thanks :-)