Invasions and Logistics

[generalvikus]

Having started a new game as the USA in 1900, I have been confronted with the interesting logistical challenges which face the United States Navy in the period when going around the Cape of Good Hope is a quicker way to get from the East Coast of the United States to the Far East than going around Cape Horn. An early war with Germany lasting approximately from late 1903 to early 1905 saw the High Seas Fleet accomplish the impressive feat of launching battleship sorties against both the east and west coasts of the United States regardless of the minor detail of not having any bases there, (with a little protected cruiser getting the fright of its life in first engagement of the war as it was caught alone by a German pre-dreadnought.)  It then followed up with the rather less impressive feat of declining every battle after at least one battleship and one armoured cruiser had been interned, thereby becoming the first navy in history to lose more ships to neutral powers than to the enemy. 

Nevertheless, the daring German operations caught me off guard, and the persistent threat to the continental coastline scuppered my pre-war plans to concentrate forces in the Southeast Asian theatre, which may in fact have contributed in large part to Germany escaping the war with a toehold in the Pacific and a grand total of zero permanent naval losses.

This has prompted me to give more consideration than I have in the past for the invasion mechanics. Under what circumstances can an invasion be triggered, and under what circumstances can it succeed? Is it possible, if unlikely, that an enemy battleship could appear suddenly in a quiet sector, launch an invasion and secure victory before or even after reinforcements arrive - or, conversely, is it necessary to maintain naval superiority for several turns and to win (or have the enemy forfeit) several 'support of invasion' battles before victory can be declared? 

[bcoopactual]

Feb 12, 2019 7:53:03 GMT -6 generalvikus said:

Having started a new game as the USA in 1900, I have been confronted with the interesting logistical challenges which face the United States Navy in the period when going around the Cape of Good Hope is a quicker way to get from the East Coast of the United States to the Far East than going around Cape Horn. An early war with Germany lasting approximately from late 1903 to early 1905 saw the High Seas Fleet accomplish the impressive feat of launching battleship sorties against both the east and west coasts of the United States regardless of the minor detail of not having any bases there, (with a little protected cruiser getting the fright of its life in first engagement of the war as it was caught alone by a German pre-dreadnought.)  It then followed up with the rather less impressive feat of declining every battle after at least one battleship and one armoured cruiser had been interned, thereby becoming the first navy in history to lose more ships to neutral powers than to the enemy. 

Nevertheless, the daring German operations caught me off guard, and the persistent threat to the continental coastline scuppered my pre-war plans to concentrate forces in the Southeast Asian theatre, which may in fact have contributed in large part to Germany escaping the war with a toehold in the Pacific and a grand total of zero permanent naval losses.

This has prompted me to give more consideration than I have in the past for the invasion mechanics. Under what circumstances can an invasion be triggered, and under what circumstances can it succeed? Is it possible, if unlikely, that an enemy battleship could appear suddenly in a quiet sector, launch an invasion and secure victory before or even after reinforcements arrive - or, conversely, is it necessary to maintain naval superiority for several turns and to win (or have the enemy forfeit) several 'support of invasion' battles before victory can be declared? 

You need a 4-to-1 advantage in naval strength in an ocean region for the chance of an invasion in that region to occur.  In RTW1 you don't have any control over which territory in the region gets invaded but they are changing that in RTW2.  I don't know if there is a guaranteed way to ensure victory.  I always try to maintain a greater strength in that region (even if it still isn't the 4-1 that started off).  I believe, but don't have any solid evidence to support, that the greater the difference in naval strength in the region the faster and more likely the invasion will end in that side's favour.


One of the later changes to RTW1 did modify that so that now you will see missions that are listed as being in support of the invasion (or defense).  Winning those fights improves your chances of success and losing (or declining the fight) reduces them.  Again, I don't know if there is a specific percentage increase/decrease to that.  There is either quite a bit of randomization built in or we just don't have enough information about what goes on behind the scenes in the game's code to be sure.    

[imryn]

I too am interested in how the invasion mechanics work in RTW and how they will work in RTW2. I am baffled by them in RTW - I have had a big fleet sitting unopposed in a zone containing enemy colonies for a year without getting an invasion event, but in a recent war with Japan that caught me off guard they managed to trigger two invasions in the first turn of the war. In addition to triggering two invasions in turn one they also managed to get them on my most valuable colonies; one in NEA with over 600 base resources invested and Singapore in SEA with nearly 1000 base resources invested. Both areas contained several other completely undeveloped colonies.

I would be very grateful for any light anyone can shed on how invasions are triggered and how the AI determines which colonies get invaded.

[bcoopactual]

As far as I know, base capacity does not affect the likelihood of an invasion. 


I can't find a reference to it but I want to say that coastal batteries do make it less likely (or requires a greater advantage in forces) for the invasion event to fire.


Also, I'm pretty sure that home areas and any territory worth more than 10 points can't be invaded.


I apologize for giving a lot of "I think" and "my guess is" answers.  


     

[imryn]

Feb 12, 2019 8:40:52 GMT -6 bcoopactual said:

As far as I know, base capacity does not affect the likelihood of an invasion. 


I can't find a reference to it but I want to say that coastal batteries do make it less likely (or requires a greater advantage in forces) for the invasion event to fire.


Also, I'm pretty sure that home areas and any territory worth more than 10 points can't be invaded.


I apologize for giving a lot of "I think" and "my guess is" answers.  


     

I didn't think that base resources was a factor, but when both of the invasions managed to target my most heavily developed colonies with laser like precision, completely ignoring the dozen other undeveloped (and presumably much less heavily defended) colonies I started to wonder. Loss of those colonies would have crippled my ability to project power into both SEA and NEA as I had invested heavily in those two colonies and neglected all the others. If I was playing Japan, and if I was able to target invasions, I would have picked those exact two (out of a dozen) to invade. For the AI to "randomly" select them and trigger instant invasions strikes me as unlikely.

Does the point value of possessions change at all? If we invest in a colony through base upgrades and shore batteries can we raise the value to the 10+ threshold?

[bcoopactual]

No, the point value doesn't change. The only real benefit in RTW1 for upgrading a base is to have enough base capacity to fully support the battlefleet in that area. I usually stop at about 300 total in Southeast Asia (as the USA player) and up around 450 in Northern Europe if I'm lucky enough to get Finland, the Baltic States or Ireland.

Coastal artillery are a separate discussion and have their own benefits.

[JagdFlanker]

i'v played a million hours of the game and i can tell you that there doesn't seem to be any logical trigger as to when colonies get invaded - i tried everything, and it 'just happens'

the only time i regularly invaded territories was recently when i decided to experiment and created a starting fleet of 30 4000t CL raiders, and even though they were all set to raider they invaded everything they went near - which i thought was odd since i figured raiders wouldn't set off invasions

i will also add that in experimenting with coastal forts they did absolutely nothing to prevent or delay invasions, even if i stacked a pile of forts on 1 island/territory.  i think i put 6 10" forts on 1 island, and the enemy invaded 1 turn and took it the next even though i had some ships in that seazone

[garrisonchisholm]

bcoopactual

Hugh?

[aeson]

Feb 12, 2019 17:57:34 GMT -6 garrisonchisholm said:

bcoopactual

Hugh?

Nah, that's Third of Five. They're clearly different.

[director]

I thought it was bcoopus.

[dorn]

Now that it is clear that on other thread there were thought about sci-fi strategy. Quite interesting that a lot of naval fans are sci-fi fans too.

Is there minimum required strength (points) for naval invasions?

[imryn]

Feb 12, 2019 14:57:16 GMT -6 JagdFlanker said:

i'v played a million hours of the game and i can tell you that there doesn't seem to be any logical trigger as to when colonies get invaded - i tried everything, and it 'just happens'

the only time i regularly invaded territories was recently when i decided to experiment and created a starting fleet of 30 4000t CL raiders, and even though they were all set to raider they invaded everything they went near - which i thought was odd since i figured raiders wouldn't set off invasions

i will also add that in experimenting with coastal forts they did absolutely nothing to prevent or delay invasions, even if i stacked a pile of forts on 1 island/territory.  i think i put 6 10" forts on 1 island, and the enemy invaded 1 turn and took it the next even though i had some ships in that seazone

That's interesting. Could it be linked to the number of ships rather than the tonnage of ships? I have put 10 obsolete B's in a zone unopposed for a year without getting an invasion trigger - that's over 1.5 million tons of ships - and both the colonies i wanted were worth 5 points each, but maybe I would be better off hanging on to all my obsolete CA's and CL's for this instead of the B's. I wonder if having ships fitted for colonial service makes any difference. I would think it should seeing as the description states that it is extra berthing for marines but i suppose it might not have been factored into the algorithm.

[bcoopactual]

Feb 13, 2019 5:39:59 GMT -6 dorn said:

Now that it is clear that on other thread there were thought about sci-fi strategy. Quite interesting that a lot of naval fans are sci-fi fans too.

Is there minimum required strength (points) for naval invasions?

I'm only aware of the 4-to-1 ratio requirement.  I don't know if there is a minimum force level as well.  

[imryn]

Just an update on invasions. I am in a war with France and Germany which has been running for 21 months so far. France has two 5 point colonies in SEA and I have had 8 BB's and 4 BC's sitting there for 19 months now without triggering an invasion. France has occasionally had one MS in SEA, but for most of that time has had absolutely nothing, and nothing for Germany either.

I suppose it is no surprise that this mechanic is broken seeing as it is getting completely replaced in RTW2, but it is frustrating.