Defending coastal cities

[nfw]

Maybe I'm still biased from playing SMAC, but there seems to be no way to defend coastal cities (save for building a ridiculous amount of warships and ring the entire coastline),

In my current game (can't take screenshots for some reason) I happen to be on a long, thin continent, the western tip is only 16 squares away from the eastern one (standard size map). There really isn't a realistic amount of frigates I can build to catch every ship, the Maya or the Inca just came at me with a 12 strong invasion fleet, even though I declared on them a couple galleons still made through.

So is the common practice to just let them land and kill them then?

 

[Dhoomstriker]

Rather than having a "solid wall" of ships, I think that it would be more important to have a few defensive ships that can attack AI ships that come near. For you to know when they are coming near, you'll need a few ships that are farther out, which can "scout" for incoming boats.


Plan to try and intercept the enemy boats at a point where it would take them more than 1 full turn to be able to move and unload troops on the shore.



As for letting them land--sometimes, if your navy is inferior, or can't spot the incoming enemy ships in time, it's your only choice.


Your best defense is to have a lot of siege units--particularly Catapults or Cannons--which can attack the stack that lands. The AIs tend to land their units in one big clump, meaning that the collateral damage from your siege weapons plays a particularly strong role in the conflict.


If you know that war is brewing, you can also proactively chop Forests that are in the horizontally, vertically, and diagonally adjacent squares to your Cities, so that the best defensive terrain that invaders can land on will be unforested Hills squares.


Units that are mobile (2 movement points) like Horse Archers, Cuirassiers, and Cavalry can also help in fighting off these stacks, as you don't have to station units in every single City if your units can move around.


It also can't hurt, if you know where an AI is likely to land, to build a City Wall and a Castle in the City next to where you think that the AI will land, giving your defensive units a considerable advantage against the AI units that you aren't able to kill off.


SOMETIMES, you can "trick" an AI that has landed into not attacking and just sitting there and healing by throwing a single siege unit (like a Catapult) at its stack. Doing so could potentially buy you a couple of turns to move supporting units from other Cities, to whip units in Cities that are close to there, or to draft units in Cities that are close to there.


If you have Railroads or later Airports, you also gain mobility with your defenses, allowing you to more easily counter enemy troops that land.

 

[Grashopa]

I just let them land, I mean they are going to declare and take a city the first turn anyway.

 

[Scoottr]

How would you set up ships to 'scout' when the AI hasn't declared yet against you? You can set them to trigger on when a enemy units comes near, but if the AI hasn't declared, they are not an enemy unit yet.

 

[Farm Boy]

How would you set up ships to 'scout' when the AI hasn't declared yet against you? You can set them to trigger on when a enemy units comes near, but if the AI hasn't declared, they are not an enemy unit yet.

You can scout navally if you have the ships.

Use the BUG mod. Use it.

It will alter the interface so that you know when an AI enters WHEOOHRN mode. When that happens, determine how likely you are to be the target. If somewhat to very likely, start visually scanning for boats.

 

[hoplite-1]

Personally I think intercepting the AI's ships is a bad idea, for these reasons:
- He's fighting a defensive war, and by using ships he sacrifices the huge amounts of defensive bonuses he would get from garrisoning cities, such as walls/castle, terrain bonuses, unit upgrades/abilities, etc
- Your navy often has to operate outside of your borders, making it expensive in upkeep
- The AI usually targets the same city and lands their units in a big lump making them
vulnerable to artillery

 

[Farm Boy]

^^^ these are good points plus, often, if you intercept the stack then you need to declare war on the AI rather then vicey versy which can be unfun diplomatically.

On the other hand, if you are playing catch-up on military production then killing an AI transport 4 for 1 might be an attractive prospect. Plus, the tac nukes don't irradiate your production base if you use them at sea(I have used them at sea before, haven't I?).

You can also be cheesy if necessary if you successfully notice an incoming intercontinental invasion and beg the AI for 5 gold. 10 turns to try and notdie!

 

[Dhoomstriker]

How would you set up ships to 'scout' when the AI hasn't declared yet against you?

I understood the original message to be about a case where you already suspected that an attack was coming, and had then decided to declare war on the AI, and also had a bit of a navy set up to intercept them:

the Maya or the Inca just came at me with a 12 strong invasion fleet, even though I declared on them a couple galleons still made through.

But, you have asked a really great question! How do you scout when the AI has yet to declare war on you?

Farm Boy makes a good point on the matter:

so that you know when an AI enters WHEOOHRN mode

However, you don't necessarily have to have BUG, as long as you talk to each of the AIs regularly and hover your mouse over another Leader's name that they could potentially be asked to declare war on. That's the other way of finding out if an AI is planning a war.

Other situations where you can anticipate being declared war on are:
- You have recently refused a demand from an AI
- You have recently gotten into a war with a different AI who has good a good relationship with an AI that hates you (i.e. the first AI that you are at war with can bribe the other AI into the war against you)
- You have recently cancelled trading with an AI thanks to accepting a request to do so from a different AI
- You have recently switched Civics away from a Favourite Civic of an AI
- You have recently switched Religions away from a Religion that you share with an AI

The first two situations are the most likely to be "instantaneous" war declarations out of the bunch, while the other factors might take some time before you get attacked.


So, keeping an eye out for an AI that has "too much on their hands" and also dislikes you, or for any AI that hates you, especially if you give them a good reason (see my list above for some possible reasons), could be someone whose boats you will want to "scout" for.


If you know the relative placement of their island/continent compared to yours, simply station a a boat like a Caravel between your island/continent and theirs. The AI will send their ships in a straight line towrds their target, so you can count on this fact greatly in figuring out "where" to scout.

You can set them to trigger on when a enemy units comes near, but if the AI hasn't declared, they are not an enemy unit yet.

Annoying as it may sound, if you suspect that an AI is going to attack you and you have placed a "scout" ship, then to me, anyway, scouting means NOT putting the ship on Sentry mode. To me, it means Skipping its Turn each and every turn (pressing the Spacebar). It's a bit annoying, but if you're going to the trouble of scouting for a fleet from an AI that you suspect may be declaring war you on, it will be a limited amount of game turns that you will be performing this scouting action, so I'd say that having to manually end the scouting boat or scouting boats' turns manually is a small price to pay for the information that you gain.


IN FACT, if you have a limited number of scouting boats that don't cover a wide view of the ocean, then it can be worth your while to manually patrol your scouting boat back and forth each turn, using up all of its movement points. I would send it its full movement points in one direction on one turn, then back the same way that it came on the next turn. Presumably, you'd send it in a direction perpendicular to the expected attack vector or vectors from some of the AI's Cities and your Cities.

Personally I think intercepting the AI's ships is a bad idea...
- Your navy often has to operate outside of your borders, making it expensive in upkeep

What's great about figuring out who your future enemy or enemies might be by monitoring diplomacy is that you only need a few scouting boats outside of your territory.

And, you don't even necessarily NEED to intercept the enemy AI's navy.

However, having that extra turn or two of knowledge of when the AI's boats are coming and approximately on which vector (in which direction they are travelling), you will buy yourself an extra turn or two to whip and/or draft land-based units and to move existing and new land-based units into position.

So, performing the diplomatic analysis and the relevant scouting-boat placement actions do not REQUIRE you to intercept the enemy ships, but they give you the flexibility to do so if you have a defensive navy, while also giving you time to muster your ground troops. You should plan to muster your ground troops even if you do have a strong navy, as often evenly-matched ships can lose battles that you were planning on winning.

In essence, you'll save on land-based unit costs until they are needed, but will also have time to whip or draft or move them into position in time if you do perform some scouting with a few boats.

- He's fighting a defensive war, and by using ships he sacrifices the huge amounts of defensive bonuses he would get from garrisoning cities, such as walls/castle, terrain bonuses, unit upgrades/abilities, etc

As far as I understand it, we're talking about declaring war on an AI that has already committed a good portion of its navy and ground troops into a stack of boats that are headed your way.

So, I am not sure that I see the difference in terms of the number of troops that an AI will field if they declare war on you on the turn that they land units in your territory versus you declaring war on them one or two turns earlier, to try and "pick off" some of their invading navy before it can reach your shores.


Certainly, if you want to be able to have a good chance at getting a good diplomatic relationship with the AI that is "coming to get you" after the war, as well as keeping good diplomatic relationships with the AIs that are Pleased or Friendly with the aggressor, then allowing the AI to declare war can "save you face" in terms of international diplomacy. And that consideration is certainly a strong one to favour (letting the AI declare war so that he/she drags their name through the mud, instead of you dragging your good name through the mud), especially if you think that you will be able to muster sufficient ground forces to be able to beat off the attack, or to at most lost 1 City.

Expect that the City will get razed, though, and then you'll feel happy if it didn't get razed, instead of feeling unhappy and disappointed when it does happen.

The AI usually targets the same city and lands their units in a big lump making them vulnerable to artillery

That fact is really good to keep in mind for future attack waves or future war declarations from the same aggressor. However, often you won't know where that City will be until after the first war is declared. Having a few scouting boats between you and the potential aggressor can help, but it is also hard to tell the exact vector of any invading ships that you DO manage to spot unless you turn on the "Show Friendly Moves" game option, which may not be practical if you have visibility of many different AIs' units, as the game would just slow down too much in order to have to watch them all.

To counter this tedium, you can have two scouting boats along an expected attack vector, one being about 5 squares closer to the AI than the other boat, so that you'll see the AI naval stack's final position after two turns. Using that info, you can extrapolate their attack vector and get a pretty strong idea about which of your Cities they are gunning for.

 

[yena]

I often send caravels to civs I think likely to attack me, to look for coastal cities with lots of transports/galleons. Once I found one, I will leave the ship there and check it from time to time. When I find that the enemy fleet has left port, it is time to summon my home navy and prepare for defense.

 

[hoplite-1]

As far as I understand it, we're talking about declaring war on an AI that has already committed a good portion of its navy and ground troops into a stack of boats that are headed your way.

So, I am not sure that I see the difference in terms of the number of troops that an AI will field if they declare war on you on the turn that they land units in your territory versus you declaring war on them one or two turns earlier, to try and "pick off" some of their invading navy before it can reach your shores.

But that only works if he just sends transports. If the AI mixes in other ships as well, your chances go down. For instance if he is 1 turn from landing and has 6 frigates+7 galleons, I need at least 7 frigates to sink one transport. This is assuming my frigates beat his frigates every time (a 1 in 64 chance). So the best possible outcome is I spend 7 frigates to sink 1 galleon. Essentially I've traded 7 land units for a 1/64 chance of killing 3 of his

The odds obviously get better if you have a gigantic naval stack and he is several turns from landing. But it will never be cost effective, you need a navy twice as big as his to stop him with any certainty. Whereas if you let him land, you can use an army half his size to defend a city with all the bonuses your land units receive.

You also suffer a reputation hit by attacking him first, as you mentioned.

I do agree that scouting ships are important though because otherwise you won't know which cities to garrison.

 

[MrMestopheles]

You don't need ships only to shoot his invasion troops. Blockades can be quite devastating for coastal towns...
About scouting: Best unit for scouting is the zeppelin. I don't understand, why it is put to obsolete, as there are no further aero units that can look for submarines.

 

[nfw]

Some great points in this thread, thanks guys.

 

[Peregrine]

Everything I've read in the replies so far seems good--I do the same things; scout w/picket ships 6-10 tiles from shore, while holding back the heavy fighting ships nearer shore so as to make concentration easier. If you have them, submarines are excellent for these purposes. A sub can sit adjacent to an enemy coastal city, inside its cultural borders while not at war. While doing so, it can spot enemy concentrations of ships, especially the movement of transports moving up and down the enemy coast. The subs can follow the transports to see where, exactly, they are concentrating, and can then watch the enemy fleet leave port and, as mentioned above, determine its vector path. WHEN the DoW occurs, these same subs can instantly blockade the enemy ports, severing trade routes, destroying oceanic resources, and denying all sea tiles to the blockaded cities.

In late game, when I start a war, I make sure to have subs already posted at every single enemy port. The blockade starts on turn 1.