How many military units should I build?

[The Mighty Quinn]

Obviously this is very dependent on context, but say I'm going for some non-domination victory, have 10-12 cities and aren't planning to attack anyone. About how many units should I have to be able to deter the AIs from attacking me? How concerned should I be about keeping my units relatively up to date? I've been aiming for about one unit per city, not more than a couple eras out of date, but I feel like I'm using too much production and gold on that and not being able to focus on my wincon.

 

[Planktonic]

Not a hard rule, but generally I try to keep my military strength to at least 1/3 or 1/2 of the military strength of any worrisome neighbor. I do think it is important to have at least one up-to-date unit, so your city defense strength is adequate. I got surprise DOWed once in a Deity game by Shaka and had to spend almost 1000 gold just to purchase a contemporary unit as I had let my city defense lag pitiably.

 

[Ordnael]

I don't look at the military strength statistics (probably should take a look now and then) and sometime manage do deter the with little more than one unit per city, mostly to keep barbs away and destroy their camps.I always strive to keep my units as modernized as possible...it might get though during the oil era, but as soon as I hit aluminium deposits I build some advanced bombers to compensate.

 

[The Highwayman]

In SP, just enough to ward off a potential threat so you don't need to go into panic mode if a surprise declaration occurs. That's not much tbh. Aside from that, military units that satisfy eurekas and barb clearing duty is the main role in non dom games.

 

[Lonecat Nekophrodite]

At least one 'up to date' ranged unit (archers) one inside the city, the other inside border encampment
depend on AI. it is recommended however to post additional anticavalry footmen there (also needed to be 'up to date')

If your city or district is at seashore hex. you need to station a siege unit inside the city instead since it generally has stronger attack against enemy ships of any kind. while it takes several turns to sink a barb galley or quadrireme with an archer. it takes less turns to do so. (and invaders (barbs) tend to be naval units) with a catapult.

 

[EdTice]

Are you trying to discourage an invasion or successfully repel one? Those are two different things.

If you want to discourage an attack you will need to have two units per city. One ranged and one non ranged. Your city strength is based on that of the garrison units strength

If you want to get attacked and successfully defend (maybe for the DoW boost) keep older era units in your cities. Just make sure you have the gold and resources to upgrade them if you get attacked

I actually prefer the second strategy because units have a maintenance cost. If you have ten cities you can easily keep two ancient or classical era units in each city. And pay essentially no maintenance.

If you get attacked or see troops massing on your border just upgrade those units as needed Just don’t get tempted to spend that gold because the AI knows and will atraco sr the most inopportune time

 

[planetfall]

It would be easier to help if you had a screen shot example. Key factors seem to be: 1. distance between their civ and your closest city, 2. which civs? military civs need more distance. 3. what is the gap between your mil strength and theirs? non-mil civs will allow you to play with larger behind numbers than military civs. 4. what are victory conditions? 5. What difficulty level: high levels mean you need more military. 6. gap between their strongest unit and your strongest unit. 7. Which civ6 version: vanilla, R&F, or GS? 8. Do you have key stat resources available?

 

[vorlon_mi]

Obviously this is very dependent on context, but say I'm going for some non-domination victory, have 10-12 cities and aren't planning to attack anyone. About how many units should I have to be able to deter the AIs from attacking me? How concerned should I be about keeping my units relatively up to date? I've been aiming for about one unit per city, not more than a couple eras out of date, but I feel like I'm using too much production and gold on that and not being able to focus on my wincon.

You don't mention which difficulty you're playing; I tend to play a lower difficulty than many people here.
@planetfall 's question about how close your neighbors are is also very relevant.

Number: having a ranged unit in each city is a good starting point. Having a squad of faster-moving attack troops, perhaps 4-6, can respond to barbarians and an invasion. Buying units with faith (having built the Grandmaster's Chapel in R&F and later) allows you to respond to a sudden aggression.

Up-to-Date: This aspect can be tricky, because resources are involved. In your empire of 10-12 cities, you will probably have both horses and iron. That will allow your units to be upgraded with gold, as your economy allows. Once you research Military Engineering, you will need to find Niter either on your territory or trade for it. With 12 cities, you may indeed have some locally. You may want to mount a limited war to secure some. Coal is more important for naval units than upgrading your land units. Having both coal and iron will let your military engineers build some railroads, that allow your rapid attack troops more mobility.

In my experience, the bigger challenge is Oil. It tends to be more scarce, but one cannot upgrade Line Infantrry, Bombards or Cuirassiers without it. Even if you're pursuing a non-denomination victory, you may need to grab more land to get the resources you need to keep your units up-to-date.

 

[Quintillus]

Which era are we talking about?

For me, it's highly dependent on the level of defenses my cities have. If we're talking the Ancient Era with no walls, then yeah, a ranged unit per city and a few spare non-ranged units is nice, otherwise barbarians can be a major pain. Even with level one walls, having a unit to finish off the barbarians more quickly is nice.

Once we get to medieval or renaissance walls, or the level 400 defenses in each city? If I have 10-12 cities and no plans to attack, I don't know, I might keep about four units around? More if I have old ones that can sit around for low maintenance, and/or have the civic that enables them to act as military police and increase happiness, but just enough to launch a counter-attack would seem sufficient to me as a standing force.

Why not more? It's a waste of shields and money. Units are expensive in Civ VI, better to spend that on building up the economy. They also cost money to maintain, after the earliest units. So you either spend your shields on units and spend your money supporting them, or you spend your shields on commercial districts, don't spend your money on units, and have even more money. Or invest in science or production or culture. Either way, build or rush a couple of units at the relevant border zone, and you've probably saved money overall, and have certainly saved shields, giving yourself a stronger economy.

But why build walls? They cost shields, yes, but don't cost maintenance. Certain governments also have bonuses from them, and there's a civic that gives half off their cost, which can make them a cheap form of deterrence compared to units. And even with basic walls, the city gets ranged bombard, which is essentially a ranged unit. Thus I've found them to be a good way to ensure I don't have major concerns at the border, while also not spending much.

However, I'm also not playing Diety... things may change there.