City Defense Discussion

[NickGabben]

How do city defenses actually work? I don't think I've ever really understood that. I know that the defense (the percentage you see on the city, e.g., +40%) goes up with culture and also when you add walls and castles (and Chichen Itza). But what is it you actually bombard away? Is an attack against let's say +23% always the same or does it matter where the defense comes from? Do all relevant/valid defenders get a +23% on their strength (ignoring other bonuses, like fortification and the like and ignoring units that don't get defensive bonuses at all)?

I've never really bothered with this because either I have siege and then I more or less always take the defenses down to 0 before attacking, unless I'm using infantry against longbows or something else similarly one-sided - or I go mounted and then I just go for it without any further consideration. (Not claiming this is optimal in any way.)

 

[AcaMetis]

The listed city defence percentage is a straight combat multiplier that units in that city get in combat. A city with +50% defence works basically the same way a forested hill does in terms of defence, except for the city defences being it's own modifier (I.E. City Raider only works against units stationed in a city/fort, Archers get +25% bonus when stationed in a city/fort, etc.).

A city's defence rating is always the higher of either it's cultural or structural (walls/castles) value, they both work exactly the same. The exception is attacking units that explicitly ignore walls and castles, which will always use a city's cultural defence rating regardless of whether it's higher or lower. Generally speaking, anything in and beyond the Gunpowder era will ignore walls/castles as a rule.

EDIT: One addendum, Chichen Itza(?) applies it's +25% so long as the civ that controls it has not researched Rifling (which obsoletes the wonder). It does not count as a structural defence bonus that gets ignored by attacking units which ignore walls and castles, so long as it's not obsoleted it applies.

 

[NickGabben]

Ok, thank you, but I'm not quite sure that answered my question. Or maybe I didn't quite get my point across. At least, I still don't get it

Let me present some examples.

1. I attack a city with +20% cultural defenses (no walls/castle). A defending archer gets a 1.2 multiplicator - correct?

2. I attack a city with +20% cultural defenses and walls. This shows up as +45%, right? If I attack with an axeman, a defending archer gets its strength multiplied by 1.45 but if I attack with a musketman instead, the archer has its strength multiplied by 1.2 (musketman ignores the walls) - correct?

3. What happens if I bombard 10% of the city with walls before attacking? What 10% have I chipped away (I believe this would show as +35%)? Would an archer get a factor of 1.35 against an axeman? What happens against the musketman?

4. If I bombard a city with walls and a castle all the way down to 0%, does that remove the walls/castle protection or are they still in play somehow?

 

[sampsa]

1. Yes, assuming no fortification. It goes up to +25% for at least 5T of fortification.

2. No. Walls are +50%. But only the higher one of cultural and structural defenses is picked, so it shows up as +50%. Your musketman example is correct.

3. I do not know.

4. Once the defenses are at 0% they play no part.

 

[civac]

City defenses have a hidden HP bar.with 100 HP to start with. This I'm certain about.

From here it's speculation:
What I think happens is that if you bombard enough for the game to show you 40% defenses (-10 percentage points of the walls intitial defense of 50%) it means you did 20 damage to the hidden wall HP bar.
So against the axe the city defenses would be +40% for the defender. Against the musket it would be 20% * 80 / 100 = 16% defenses.

 

[antimony]

That seems correct, that explains why cannons are sort of affected by walls/castles even if they aren't in the same way as trebs/cats.

So imagine a city with 60% cultural defense and a 100% castle.

A treb only does 4% bombard on the castle. A cannon does its full 12% but it still takes 8.5 hits to take out all defenses, rather than 5 without castle. The % decrease the cannon 'sees' out of 60% is less than 12 each hit.

 

[lymond]

Moderator Action: Transferred related posts to its own thread, which appears to make for a good discussion. Cheers- lymond

 

[NickGabben]

This all seems to be way more complicated than I had ever imagined! I had never heard of hitpoints for cities before, but maybe I slowly begin to get a minor understanding of things (I doubt it will change my play style, though, as I think it'll still be all or nothing for me...)

 

[s.bernbaum]

That hit point for cities explains something that has puzzled me. Frequently I will bombard a city and the game says city defenses reduced to (for example) 60%. However, the city only had 40% to start with and after the bombard is has (for example) 34%. So the report must be the reduction in the city hit points not it's defense %.

 

[civac]

What you are describing happens when you use cannons vs walls/castles. I don't think wall HP appears overtly anywhere in the game. I know about it only from looking at the code.

 

[Lennier]

Or when you use trebs/cats in a stack with gunpowder units. With your stack selected, it shows the gunpowder defense (w/o walls or castles). Selecting a treb to bombard, you see the non-gunpowder defense (including walls and castles.) Note that walls and castles can reduce the rate at which cannons and artillery reduce the culture defense.

 

[Plains-Cow]

You don't need to worry about city defense if you have enough attack confidence.

 

[NickGabben]

A related question: How does the fortification bonus work (or rather when is it given up)? If I fortify a longbow on turn T, then normally on T+5 he'll have reached the maximum bonus, right? What happens if I wake the unit by clicking on it, but do nothing but realize my mistake and fortify him again? Has he forfeited his bonus or does it (i.e., the bonus) remain active? If I wake him up, move him out of the city (on roads), then back to the city on the same turn and fortify him again, does he then have to start over (which would be fair enough, I suppose)?

 

[Qactus]

Waking the unit does not interrupt its fortification. Moving it does.

 

[NickGabben]

Alright, thanks!