What conditions trigger an amphibious attack?

[dalgo]

In my games I have almost never seen an amphibious attack against one of my colonies. Maybe in a couple of games I’ve had one or two units attack me by sea but that’s all. Not that I’m complaining mind, whatever I’m doing right I want to keep on doing it. So just what does trigger an amphibious attack?

The difficulty levels I’ve used have been Explorer up to Revolutionary yet when I looked at someone else’s game at Pioneer (the second easiest level) he had a horrendous WOI with relentless amphibious attacks every turn. Surely it shouldn’t be a harder game at the easier difficulty level? The only major difference I could see between his game and mine is that he was playing an island map, which did reduce the landing area for troops. They had just two land tiles adjacent to his colony and two or three more on his island where they could land, whereas in my games I mostly have an open coastline with plenty of landing room. Would this make a difference?

It's not that my colonies are heavily protected, quite the opposite. Because I've never had any problems I use all my troops for attack, often only leaving just a couple of cannons to defend my colony.

 

[I_M_Weasel]

From my (limited) experience my citties defended by infantry are not amphibiously attacked, if I defend a town with just dragoons then I get destroyed and don't win a round.
There may of course be a completly different real explanation.

 

[UWHabs]

I had a mix of soldiers, dragoons, and cannons in one of my towns and I was roundly beaten down turn after turn, until I decided to just give up the town and amass my cannons and troops outside of it, to retake it a couple turns later. Turning point of my war.

 

[dalgo]

I had a mix of soldiers, dragoons, and cannons in one of my towns and I was roundly beaten down turn after turn, until I decided to just give up the town and amass my cannons and troops outside of it, to retake it a couple turns later. Turning point of my war.

What difficulty level were you playing?

 

[UWHabs]

Second highest.

 

[Antilogic]

I suffered a number of amphibious attacks in two games, and in both games, I noticed a pattern as to which cities received the brunt of the attacks:

Using the following codes:
C: city
W: water
L: land

Here was what the map looked like each time it happened:
L L L
L C W
W W W

L L W
L C W
L W W

...and the route my caravel came on the first turn, the origin where the King's army came from...was the SE. It appears that if the King sends his loaded Men 'O' War along a diagonal and sees your city without seeing any land, then he will launch a direct amphibiously assault against you.

I would suspect similar behavior if the situation was changed such that the origin was in the NE and the land was clustered in the SW.

EDIT: I should note that in both cases, my towns were incredibly well-defended (fortresses, cannons, and foot soldiers, the works). I don't think the strength of my garrison had anything to do with it.

 

[UWHabs]

I don't think it's entirely dependant on your starting spot, since my last game, they didn't go after my first city. It was more my caravel started one spot, went due west, settled, then my second city was down the coast from there. However, it was from where I generally sent my boats to and from Europe, so maybe they come in based on your most common route to Europe?

 

[Antilogic]

It wasn't my starting city in one case, because I searched the coastline to find a better spot. However, in both cases that I was amphibiously assaulted (and this is a couple Men 'O' War unloading an entire stack on the city in a single turn), it was a city that was closest to my European origin and had the particular landscape I tried to diagram above.

 

[Refar]

It might depend on un-/availability of a "safe" plot to land - i.e. if there is defensive terrain adjacent to both coast and your city, where AI can make landfall, it will often prefer to land. On the other hand, if the only spot they can land is a exposed flatland, they might rather choose to attack from the sea.

Also, if you have a river next to your city, the plots from where it would need to attack cross the river are probably "less desirable" landing spots for the AI.

 

[Bloink]

I think getting an amphibious assault is mainly dependant on 2 things.
1. Dragoons only in a settlement(or only 1-2 soldiers along with them). This is my main strat at the outset of WoI and seem to get amphibious assaults alot initially.
2. As Refar said, the lack of more than one defensible landing point.

None of this is tested, it's just my "gut" feeling. Last game I played, the colony that was getting hit repeatedly by amphibious assaults, met exactly the conditions above. While the 2 neighboring colonies that had forests/hills on either side didn't get hit with an amphibious assault of any meaning.

 

[dalgo]

I think getting an amphibious assault is mainly dependant on 2 things.
1. Dragoons only in a settlement(or only 1-2 soldiers along with them). This is my main strat at the outset of WoI and seem to get amphibious assaults alot initially.
2. As Refar said, the lack of more than one defensible landing point.

None of this is tested, it's just my "gut" feeling. Last game I played, the colony that was getting hit repeatedly by amphibious assaults, met exactly the conditions above. While the 2 neighboring colonies that had forests/hills on either side didn't get hit with an amphibious assault of any meaning.

I think your second point is the more likely reason. I rarely use soldiers at all in my games yet seldom get an amphibious attack. On the other hand my port colonies are spread out with plenty of landing sites between them.

 

[Dom Pedro II]

The AI will generally try to attack a plot it thinks it can take. It'll calculate the battle odds and decide accordingly.