What determines city defense?

[JaqenHahaghar]

In general, we see that cities get stronger as we progress in era. However the jump seems very discrete and it does not seem to depend on which era you are in. What determines city defense? Are there key techs, or, does it depend on the number of slots in your government?

Thanks for the answer!

 

[liv]

city strength depends on the military stength of the units you can build

 

[UWHabs]

city strength depends on the military stength of the units you can build

I think it's based on the best unit you have built. I've noticed where I build my first cavalry and suddenly my cities jump in strength. Feels like a very arbitrary number, as once I was mowing down Russia, and suddenly they pop a Cossack, and all of a sudden all their cities gain 20 points of strength.

 

[greygamer]

city strength depends on the military stength of the units you can build

Ah that explains why it sometimes goes down when I pillage the tiles around them, thank you for clearing that up.

 

[JaqenHahaghar]

Very interesting. Thanks everyone for the clarification. Thus it becomes quite important to get a precise idea on an opponent's tech progress. The sudden jump in strength is indeed what ruined my conquest a couple of times. Same thing goes with civil engineering which give walls to all cities.

 

[Victoria]

Ah that explains why it sometimes goes down when I pillage the tiles around them, thank you for clearing that up.

You want me to check it out more thoroughly @greygamer ?
If no-one else has, I'll look into it

 

[greygamer]

You want me to check it out more thoroughly @greygamer ?
If no-one else has, I'll look into it

That would be really appreciated, and save me pillaging everything in sight in the future. I thought it was pillaging districts that lowered city defence values

 

[Victoria]

Sure, pillaging is great otherwise unless you want the city. Will post when I know more

 

[liv]

I think districts do add some points to the defense. In my empire my city with no districts seem to have the lowest and the largest ones (also the ones with the districts the highest). Having a palace also adds a few points it looks like.
Looking forward to hearing about the checking out.

 

[ShinigamiKenji]

I'd guess it might have something to do with the level of wall unlocked too.

For example, if you have Civil Engineering, but don't have Renaissance Walls yet.

AFAIK, additional districts also contribute to defense.

 

[Victoria]

OK this while are is not that complex but I imagine you will want a full picture so I'll do a mini guide when I get everything together

So in the classic era we can see the below
+3 for the capital while +2 for walls!
+2 for each district as expected, well spotted!
+x for troops being garrisoned in there... I'll check out other eras.

So walls only give +2 defencebut they do allow you to shoot back ... and
they have 50 HP
And it also reduces attacks by the looks of things but that bit is suposition based on expected damage currently

so when you settle your first city in future and it shows a defence of 13

And your second only shows a defence of 10, you know why

I highly suspect era has something to do with Base strength

Hopefully you can appreciate there is a lot to check out but that should give some basic answer.
Gonna check if base increases with era next
Hopefully this is helping @JaqenHahaghar

... and @greygamer... tile improvements do not help apart from districts as you said,,, but feel free to keep looting for greed.

 

[Victoria]

Some interesting stuff going on

Nothing for an era change
Nothing for a government increase/change
Nothing for Civic change
I built a heavy chariot and got +8 to defence
I built a horseman after that and +7 to defence
The then restored and built a horseman and got +15 for defence
Then built a chariot and got nothing
At this stage I am guessing the later base values grow as you build each new cavalry unit which is really weird for city defence.
- edit: crossbow gave a + as well but too tired. done enough for today

City states get +1 to defence for each envoy from the civ with the most envoys sent to them. This bonus is called "outside influence" Nothing extra for Suze

A garrisoned slinger gives nothing to defence
A garrisoned archer gives +5 to defence
A garrisoned warrior gives +10 to defence
A garrisoned heavy chariot gives +3 to defence
A garrisoned horseman gives +10 to defence

However older era troops (looks like 2 Eras) provide a lot less (warrior +2 in Renaissance while Archers are 0)

City Attack value is not shown anywhere until you prepare for attack and is your city base value. The trouble is you cannot see your base value normally, it is not shown anywhere for your own civ. he number you see on the screen for a civ is purely defence value and typically a fair amount higher than attack value.

Also seeing some weird stuff that didnot occur on recall so holding off on it for retesting, sort of indicated once you went up eras you got the previous eras bonuses... but Its not panning out on retry so far.

 

[ShinigamiKenji]

IIRC, terrain also give a bonus (I think it was something like "+2 Ideal Terrain" for hills)

I'm fired up for a testing game too. I'll start one at Settler/Chieftain so we can compare results.

I also suspect population and resources also add up to defense, so you might want to check on that.

 

[greygamer]

First off thank you very much for doing the work on this

Some interesting stuff going on

Nothing for an era change
Nothing for a government increase/change
Nothing for Civic change
I built a heavy chariot and got +8 to defence
I built a horseman after that and +7 to defence
The then restored and built a horseman and got +15 for defence
Then built a chariot and got nothing
At this stage I am guessing the later base values grow as you build each new cavalry unit which is really weird for city defence.
- edit: crossbow gave a + as well but too tired. done enough for today

City states get +1 to defence for each envoy from the civ with the most envoys sent to them. This bonus is called "outside influence" Nothing extra for Suze

A garrisoned slinger gives nothing to defence
A garrisoned archer gives +5 to defence
A garrisoned warrior gives +10 to defence
A garrisoned heavy chariot gives +3 to defence
A garrisoned horseman gives +10 to defence

However older era troops (looks like 2 Eras) provide a lot less (warrior +2 in Renaissance while Archers are 0)

City Attack value is not shown anywhere until you prepare for attack and is your city base value. The trouble is you cannot see your base value normally, it is not shown anywhere for your own civ. he number you see on the screen for a civ is purely defence value and typically a fair amount higher than attack value.

Also seeing some weird stuff that didnot occur on recall so holding off on it for retesting, sort of indicated once you went up eras you got the previous eras bonuses... but Its not panning out on retry so far.

Looks like boosts for building units is directly related to the unit base strength
Warrior = 20 = Base city defence of 10 or 20 if garrisoned in the city
Heavy Chariot = 28 = +8 to base defence or 28-10 for an 18 base defence value.
Horseman = 35 (or +7 more than a heavy chariot)
Slinger = 5 melee strength Archer = 15 melee strength so that supports a unit adds it's melee value -10
Garrisoned mounted units get heavily penalised in this respect, Heavy Chariot (28) Horseman (35) would be -25 of the base melee value. It makes sense because they are giving up mobility.

So for a better base defence research better units which makes sense as the animated defenders change with those tech advances.
I seem to remember the rule for attacking a city in Civ V was to have an attack value at least 50% of the city value, unless you wanted a siege that went on for tens of turns.

 

[Victoria]

IIRC, terrain also give a bonus (I think it was something like "+2 Ideal Terrain" for hills)

I'm fired up for a testing game too. I'll start one at Settler/Chieftain so we can compare results.

I also suspect population and resources also add up to defense, so you might want to check on that.

Testing is best done for most things on a duel hotseat at human with reveal all. No spawning barbs and you control both sides. This test in particular need you to hover your attacker over an enemy base.
Ideal terrain is if you are on a hill +3

 

[Victoria]

It seems like a warrior does half damage, I have not gone through combat.csv in detail yet.
Certainly it's all in there, the main issue is it describes city vs city when it is in fact a city shooting an attacker

 

[Draco84]

As for city attack strength it is exactly the ranged strength of your strongest ranged unit in the slinger tree.i always rush a crossbow eatly to make my cities super strong. (Its in the civilopedia)

Easy to test, one game i built 0 ranged units and my cities had 5ranged attack but 100 defence. Ai doesnt build many ranged units which is why their cities barely hurt you most of the time.

 

[Victoria]

As for city attack strength it is exactly the ranged strength of your strongest ranged unit in the slinger tree.

So... you did not build any cavalry then?
Because you may have been pleasantly surprised

 

[Unconquered Sun]

Sigh.

The strength of the city is the strongest unit you've ever built (not had!)* minus 10. Capital gives +3, districts give +2 each. Hills' bonus won't ever show up, but is active when attacking the city - it's the same as with units fighting.

Garrisoning a unit will increase the strength of the city to the strength of the unit, if higher. This, garrisoning your strongest unit is +10.

Walls shoot with the strength of your strongest ranged units from both the archers and the artillery lines.


* - basically this screws Atzecs in the beginning

 

[Draco84]

So... you did not build any cavalry then?
Because you may have been pleasantly surprised

i tried going melee units only (suprisingly effective) so i had no bombard or archer class units.the enemy couldnt really hurt my cities but my cities couldnt hurt them either.