Rabbi Hamm and the Land of Swiss Cheese

[crullerdonut]

While a pre-release of 0.98 is out, I recently completed a looong game of 0.97c. Because it went so long into the modern era, I got to try things which I usually don't have a chance to use: I ended up using the new Nuclear Submarines, I built the improved Space Elevator, etc. I also believe that I encountered a bug with the Apostolic Palace resolutions. It was also my first real experience of severe Global Warming.

I ended up drawing Hammurabi of Babylon. The settings were Pangaea, Monarch, Huts on, and No Random Events. I forgot to turn the latter on, which will have an impact later on. I also turned on Choose Religions because I saw from Sullla's AI championship that this setting adds a nice little variety. Also, this gave me the chance to name Hammurabi as "Rabbi Hamm", and I made the Code of Laws religion be Judaism, so it was fun in that respect.

One of the first things to remark on the game is how interesting the terrain was. Basically, it was like Swiss cheese. Although it was Pangaea, the land I started on was filled with inland seas and lakes, which were easily linked up by cities and Forts. This allowed additional and from by building Harbors. It also allowed me greater flexibility for choosing where to build ships, and late in the game, it allowed me to easily send Nuclear Submarines filled with Tactical Nukes over to my adversaries. I show the extent of these inland shipping lanes, with Coastal cities circled below:


The starting position was as follows:


I decided to settle 1 tile south. Soon, I met my close neighbor to the south, Sitting Bull. He was a poor neighbor. He was the first civ to research Alphabet, and he very quickly used espionage against me, causing unrest in my capital, Babylon. This had a crippling impact on my early game, reducing my main city to uselessness, and taking a long time to grow back to where it should have been:


Very soon, Sitting Bull attacked me with his Dog Soldiers, taking one of my cities, Nippur. I didn't even know this was possible, but on the exact same turn as Sitting Bull took Nippur, he finished researching Code of Laws and founded Judaism... and the Holy City happened to be Nippur. I was shocked that a holy city could be founded on the same turn as being conquered, since I thought that these things happen before units are moved. I was also unaware that holy cities could happen in cities in Resistance. Even beyond that, I was salty about how unlikely this turn of events was: I would be up against a 5/turn city in the early game, and I'd have to somehow take it back from Dog Soldiers. Well, I decided that the game was over at that point, so I restarted.


This time around, I decided to settle two tiles south from the starting position. While this wastes two turns, it put me at a better position vis a vis Sitting Bull, and made the travel south of the Babylonian inland sea more assured. I ended up settling in a straight line; I could focus on the more marginal land to the north afterwards. It was difficult to keep the easternmost city, also called Nippur, against the cultural pressure of neighboring Gilgamesh, but I managed:


I managed to maintain peace with Sitting Bull this time around, and much to my delight, he was not very liked by other leaders. I was able to bribe Gilgamesh to go to war against Sitting Bull, in return for Nationalism. Shaka, who bordered Sitting Bull to the south, joined in against Sitting Bull. Meanwhile, the other leaders were busy at war with Gandhi (what else is new? ).


Gilgamesh's war against Sitting Bull took a surprisingly long time. I was able to tech my way to Cuirassiers, and was able to conquer two of Sitting Bull's cities before Gilgamesh could get to them. As a huge prize, Cahokia contained the Pyramids, which allowed me to switch into Representation (at the expensive of reduced diplomatic bonus points with Ragnar). Sitting Bull offered to capitulate, which I thought would've been a quick and easy way to grab most of the good land from him relatively quickly, and it meant that Gilgamesh or Shaka couldn't grab the other cities before I could get over there.


However, accepting Sitting Bull as my vassal turned out to be a huge mistake. It caused negative diplomatic points with most other powerful civs, and Gilgamesh soon attacked, taking Nippur. (My precious city!)
So, while it's a bit cheesy to re-play from mid-game saves, I decided to just learn the lesson: do not capitulate civs when everyone is dog-piling against them. Just kill them. As it turns out, my fears of being unable to get to the rest of Sitting Bull's cities before Gilgamesh were unfounded, and I took Mesa Verda relatively easily. Shaka did take Mound City, however:


Cahokia turned out to be an absolute monster of a city, with several settled specialists and Military Instructors. With a Levee, powered Factory, Ironworks, and Heroic Epic, it was an absolute powerhouse of military production. I continued further with the game, teching, building up infrastructure, and making Cavalry and Cannons.

I ran out of room for pictures and files, so... to be continued!

 

[crullerdonut]

After conquering Native America, I focused on consolidating my new holdings, and researching my way to Assembly Line. When I got to Steam Power, I noticed a slight issue: I had no Coal. How could I build worthwhile Factories, or even Railroads, without that precious commodity? But, as it turns out, there was a Coal one tile south of my border, in Zululand. Shaka was not very happy with me for various reasons. So, basically it meant that I needed to conquer Zululand and grab the precious, precious Coal. To war!


The war went fairly smoothly, although Shaka did have many Cuirassiers and Pikemen. I was able to start pumping out Infantry at this point, though, and while trying to take Chaco Canyon, Shaka suicided about 7 or 8 Cuirassiers against 3 of my garrisoned Infantry. Nonetheless, I was over-extended, so I accepted peace for 10 turns, after having conquered most of what I wanted. I got the Coal, after all!


Meanwhile, Justinian declared war on my neighbor to the east, Gilgamesh. At first, they were very well matched with one another, and the war dragged on for a long time.

Another thing worth mentioning is that I had build the Sistine Chapel much earlier. This, once again, greatly aided my conquests. Newly-conquered cities are starved of land, but they have a lot of specialists; these specialists, even Civilians, produce very quickly, allowing for the city radius to be pushed out immediately after the city is under control (which was easy with Infantry). (With the Pyramids and Representation, they even produced , too.) Because it so greatly aids in conquest--and is almost essential for Culture wins--it is my opinion that with K-mod and AdvCiv, the Sistine Chapel is one of the strongest Wonders in the entire game.


While taking that screenshot, I realized that I had a Great Artist lying around. So, I sent it down to create a Great Work in newly-conquered uMgungundlovu, instantly consolidating my holdings down there:

I declared war on Shaka again and ended up taking Nobamba as well, which caused Shaka to capitulate.

By this time, Gilgamesh had really started to lose the war. I had probably a dozen turns where I could have declared war on Gilgamesh and taken a few of his cities. However, I decided against this idea. For one, I didn't want to have any significant border pressure with Justinian; having Sumer as a buffer state prevented this from happening. Secondly, I wanted to focus more on consolidating my new holdings in former Zululand, and to race towards Tanks. In hindsight, I probably should've declared war on Gilgamesh, just to take a couple cities. Oh well.
Gilgamesh capitulated to Justinian. Meanwhile, Justinian being who he is, started to really spam Christian Missionaries and send them my way. Christianity was the AP religion, so it was nice to build the Temples for the +2.

While I was previously Jewish, I switched into Free Religion, in order to avoid conflict with Justinian. I was also successfully able to bribe Ragnar out of Christianity and into Free Religion. I was very pleased--and probably lucky-- that Justinian soon declared war on Ragnar.

Then, something strange happened. According to the article on the Civ Wiki https://civilization.fandom.com/wiki/Apostolic_Palace_(Civ4)#Declare_War_on_X
religious wars should only be started against non-members of the AP. However Ragnar very certainly had several cities with Christianity, so he really should've been a member, if not a full member due to lack of Christian state religion.
Additionally, I after the measure passed (I voted "no", but it passed anyway, since I didn't have enough Christian cities at that point yet), I didn't go to war. I was under the impression that, if that resolution passes, I was supposed to go to war automatically.
Also, there wasn't any choice to "Defy" the resolution, either.
All in all, it was very strange. I included a save file of the turn where it had just happened, and below is a screenshot showing the resolution passing, but no War symbol in my scoreboard:


After this, I came to a realization: Justinian cannot declare at pleased. And since Random Events are off, once I get into this state and don't mess it up intentionally, the coast is clear! Very soon, it would just be me and him, with our respective vassals. If I switched into his state religion, Christianity, and into his favorite civic Theocracy, and if I also declared war on Ragnar... well, that's a lot of brownie points. In all likelihood, after Ragnar's death, the rest of the game would proceed in peace. So, I spent 3 precious turns switching my Civics and Religion. It ended up being totally worth it, as Justinian never did attack me for the rest of the game. Indeed, he even got to Friendly, and I was able to get a +1 bonus by signing a Defensive Pact (against whom, aliens?) with him as well.
In declaring war against Ragnar, I sent a single Tank over there just to pillage the towns. Cheesy, I know, but hey, it's free .

At this stage, I was very much ahead in terms of technology, compared to Justinian. This was probably due to Justinian being in a very drawn-out war with Gilgamesh. So, in the meanwhile, I was able to tech to Fission and Rocketry, and produced Tactical Nukes, Nuclear Submarines, and ICBMs on top of my numerous Tanks, even before Justinian was able to research Fission. I was at a stage where, if I wanted to, I could've probably won the game by nuclear warfare. Indeed it took until 1985 until Justinian built the SDI. So, I was at a stage where I could either: go for Domination, or go for Space. I've included a save file around this time of decision. Below is the power graph showing how Justinian and I were engaged in a fierce arms-race during this time, though the Nuke advantage wasn't accounted-for.


I opted to just go for space, so I halted most of my military and nuke production, just going for maximum Space. Although the Space Elevator is notoriously one of the worst Wonders in the game in vanilla BtS, I opted to try it out here, since it gives +100% space ship production, instead of just +50%. I would have to go back and see how many turns it actually saved, but I think that it actually may have been worthwhile at +100%. I started by building all the Thrusters normally; meanwhile, I researched Computers. Then I researched Satellites, and Cahokia could then build the Docking Port; meanwhile, I researched Robotics. When that was done, I was able to build the Space Elevator immediately by using 2 Great Engineers that I had on hand. After researching Composites, I could build the SS Casings at various cities quickly. Amazingly, I even was able to build it on a good timeframe at my National Park City, which had only 6 Forest Preserves (but 7 Engineers and +11 from Mining Inc ). See below:

While those were building, I researched Ecology for the SS Life Support, and then Genetics, Fiber Optics, and Fusion. Anecdotally, with the Space Elevator, it seemed that the timing worked out pretty well, with the next technology coinciding neatly with the completion of a part. From this one experience, it seems like the +100% was worth it, even if I had to research the unnecessary Robotics... at least in the case that I could instantly build the Space Elevator with 2 Great Engineers.

Despite his Domination-oriented strategy, Justinian pivoted toward Space as well, and he and I were in a tight race. I ended up launching four turns before him, just barely winning the game. It goes to show that, especially with AdvCiv, the AIs get a tremendous advantage at the end of the game in terms of capacity. Granted, Justinian also had a slight city advantage after conquering Ragnar, so after those cities came online, that probably helped him significantly, too.

There's still more to be said, so... to be continued!

 

[crullerdonut]

Now I can mention some of the miscellaneous things which I thought were interesting about this game.

This was probably the first time that I ever founded Cereal Mills (in 1866) and spread it to all of my cities. While Cereal Mills is normally a rather crappy corporation, in this case, it was the best option, for several reasons:
1. I had extremely limited access to seafood, despite my extensive inland seas. I only had access to 2 Clams; the rest I would have to purchase from other civs. That's just +1, before purchasing resources from other civs.
2. On the other hand, I had personally access to 3 grain resources, giving a guaranteed +3 without even having to purchase anything
3. I didn't necessarily want the extra from Sid's Sushi. I needed extra food in my National Park city, Erech, but that was my only city that directly bordered Justinian. So, I didn't want to risk having any border tension caused by that .
By the way, I also was able to found Mining Inc, which got me between +8 and +11. This was great.
I did enjoy the irony of having Poverty Point be my double-corporation Wall Street city, of course (It had a settled Merchant there, too, so it wasn't just for the sake of irony).

In the 1800s, I could've opted to go for State Property, instead of the above corporations. However, I believe that this wouldn't have helped me as much. For one, I had very little river access, eliminating any benefit from Watermills (I don't believe I built a single one). I was also generally low on food anyway, so I don't think that I would've gotten a tremendous benefit out of the improved Workshops. Another factor that went into this decision was that, at the time, I had a Great Merchant on hand. So, the corporation strategy seemed to be the best choice.

This was another game where I had a general lack of Grassland. I ended up building a grand total of 32 Windmills, in order to eke something out of my Tundra hills and hills in other low-food areas. So, there came a time when, despite my extensive use of Corporations, Environmentalism might have been worthwhile.

The impetus for Environmentalism was the most severe Global Warming I have ever encountered in this game. Probably due to my somewhat early Assembly Line, and my building of Coal Plants in most places, as well as a few Industrial Parks (unusual but, hey, they were actually pretty nice with their +2 free specialists in AdvCiv), as well as a somewhat high population due to Cereal Mills, and in combination with a very late end date due to the Space Race, I ended up with an insane level of global warming.

While this opened up some areas in the far north, it also caused my cities to start starving due to desertification. The from the Global Warming was noticeable, but I actually think that it could stand to be even higher than it is.
So, to be a good global citizen, during my Space Race, I tried to rapidly convert to an all-nuclear power (and some hydro) regime and building Recycling Centers.

Spoiler :

By the way, despite building all those Nuclear Plants, I never experienced a meltdown, which I was happy about. I did see one happen in Justinian's Delhi, though. So, maybe they don't need to have their frequency increased by too much.

Even earlier, I had tried to build Public Transportations. Additionally, I ended up adopting Environmentalism, as well. And then finally, after launching my Spaceship, I pillaged all my Coal and Oil resources; this was the greatest impact. After all this, I was able to get my carbon emissions down significantly.


One thing I don't quite understand is how the Change Rate of the Global Warming Index is calculated.

Due to all my Windmills and the Organized trait (reducing the High cost of the civic), the switch over to Environmentalism was actually not too bad. The first screenshot shows my economic output under Free Market, and the second is under Environmentalism. As it turns out, it only accounted for about a 10% change in the slider. Still not great, but hey, in this specific situation, it wasn't too bad, even with all my corporations.


In dealing with the Global Warming mechanic, I think that there still might be a little room for improvement. The shutting-down of Coal and Oil was one of the most impactful, due to the impact of with Factories (and Industrial Parks). While I think that it's still a good compromise that the Ironworks be reduced by -50%, I think that Railroads should still be able to be built in this late stage of the game. Perhaps with the discovery of Superconductors, Railroads could be built without Oil or Coal. Imagine that they're mag-lev trains.
There also should be a way to prevent automated workers from building Forts on these resources after you Pillage them. I just had my workers do nothing, at that stage. Hypothetically, though, it could've been relatively easy to get rid of Coal much earlier than I ended up doing it.
Another idea I had is that there could be additional UN resolutions: 1. Coal phase-out and 2. Oil phase-out. This would obsolete these resources in the same way that Fur/Ivory/Whale are obsoleted. Removing Oil does have the impact of halting the production of Modern Armor and the like, though.
Finally, although less impactful, perhaps each Future Tech could add something like 2000 Pollution Offset, to represent large-scale carbon capture and storage. Just for an example, this could be the icon displayed on the Future Tech tech:

The carbon gets captured.

In this game, I also had a chance to use some units which I very rarely ever built: the Nuclear Submarine (so-named in AdvCiv) and the Attack Submarine (the old regular Submarine). I think that it made sense for the Nuclear Submarines to carry Tactical Nukes and to require Uranium (and Fission) to work. I built an Attack Submarine with the expectation that it could act as a defense for my missile-carrying Nuclear Submarines, but as it turns out, they're both exactly the same in strength. I was hoping that there would be some way to defend the Nuclear Submarines against the easily-available Destroyers like there is in vanilla BtS, but there doesn't seem to be a way to do that with AdvCiv.

Just for fun, after winning the game, I threw my nukes at Justinian and Gilgamesh. They had the SDI but I didn't, so this was the result:


That's about it for now. Thanks for reading!

 

[Cruiser76]

That’s a good idea of adding UN resolutions dealing with specific resources. Those could really change up the end game. Leaders could still defy the resolutions causing them to fail, but they would be hit with a huge happiness penalty.

 

[f1rpo]

"Rabbi Ham(m)" – Sacrilicious

I was shocked that a holy city could be founded on the same turn as being conquered, since I thought that these things happen before units are moved.

I imagine that SiBu discovered a religion tech at the end of his turn and that the city was chosen and consecrated at that point. For a human player, the religion-founded popup wouldn't have appeared until the start of the next turn.

Then, something strange happened. According to the article on the Civ Wiki [...] religious wars should only be started against non-members of the AP. However Ragnar very certainly had several cities with Christianity, so he really should've been a member, if not a full member due to lack of Christian state religion.
Additionally, I after the measure passed [...], I didn't go to war. I was under the impression that, if that resolution passes, I was supposed to go to war automatically.
Also, there wasn't any choice to "Defy" the resolution, either.

Oops. Looks like I forgot to put this change in the main portion of the manual. I've now added:
"The Apostolic Palace can propose war against (non-full) voting members, but only full members are compelled to declare war." [kekm.25]
It's silly that a single city of the AP religion makes all the difference. That's still the case when it comes to AP membership and thus victory votes, so it might've been better to hold off on this change until a more comprehensive overhaul of the AP. But then Kek-Mod implemented the war vote change, and I decided to adopt it right away.

[...] and I was able to get a +1 bonus by signing a Defensive Pact (against whom, aliens?) with him as well.

Seems like an oversight by the Warlords developers. Vassals shouldn't count when checking if there are at least 3 teams. I've amended this for v0.98.

I was at a stage where I could either: go for Domination, or go for Space. [...] I opted to just go for space, so I halted most of my military and nuke production, just going for maximum Space.

I'm confident that you would've won that war, but, if you had wanted to win militarily, you probably should've attacked Gilgamesh much earlier (as you had contemplated too).

Although the Space Elevator is notoriously one of the worst Wonders in the game in vanilla BtS, I opted to try it out here, since it gives +100% space ship production, instead of just +50%. I would have to go back and see how many turns it actually saved, but I think that it actually may have been worthwhile at +100%.

Interesting. I've never bothered to try it. Ideally, I'd say, it should be worthwhile when being short on production in comparison with research (not the case here I think) or when having a Great Engineer or two at hand.

By the way, despite building all those Nuclear Plants, I never experienced a meltdown, which I was happy about. I did see one happen in Justinian's Delhi, though. So, maybe they don't need to have their frequency increased by too much.

The per-turn meltdown chance is the same as in BtS: 1/2000. K-Mod has made meltdowns less damaging and I've added a game speed adjustment for the probability. I think the probability could at most be increased to 1 permille (on Normal speed), otherwise, there'll be too many meltdowns on large maps and the probability of a single Nuclear Plant to die from a meltdown over a 50 turn span becomes too high. Not a balance issue really, but it becomes implausible that someone would construct these time bombs. 1 permille might be fine, or something in between 0.5 and 1.

One thing I don't quite understand is how the Change Rate of the Global Warming Index is calculated.

Me neither, but I can look it up:

Spoiler :

<Define>
   <DefineName>GLOBAL_WARMING_RESTORATION_RATE</DefineName>
    <iDefineIntVal>1</iDefineIntVal>
</Define>

iGlobalPollution = game.calculateGlobalPollution()
iGlobalDefence = game.calculateGwLandDefence(PlayerTypes.NO_PLAYER)
iThreshold = game.calculateGwSustainabilityThreshold(PlayerTypes.NO_PLAYER)
iChangeRate = iGlobalPollution-iGlobalDefence-iThreshold - iGlobalWarmingIndex*gc.getDefineINT("GLOBAL_WARMING_RESTORATION_RATE")/100

Perhaps with the discovery of Superconductors, Railroads could be built without Oil or Coal. Imagine that they're mag-lev trains.

I'm OK with disconnected fossil fuels, especially Coal, being an effective measure against GW. Seems pretty realistic. K-Mod has already added a loading screen hint about this strategy. Having to reconnect a resource temporarily in order to build railroads is silly, so I agree that it would be good to enable electric railroads somehow. Seems like many – though not all – maglevs do use superconductors for electrodynamic suspension. So at least this wouldn't be junk science. I guess power plants or Public Transportation could only make railroads available near cities. One could argue that the infrastructure for electrification wouldn't be viable in the wilderness (cf. Railway_electrification_system#Disadvantages), but the gameplay problem wouldn't be fully solved.

There also should be a way to prevent automated workers from building Forts on these resources after you Pillage them. I just had my workers do nothing, at that stage. Hypothetically, though, it could've been relatively easy to get rid of Coal much earlier than I ended up doing it.

True. One of the existing automation options or a new one should stop workers from connecting resources with building health penalties.

Another idea I had is that there could be additional UN resolutions: 1. Coal phase-out and 2. Oil phase-out. This would obsolete these resources in the same way that Fur/Ivory/Whale are obsoleted. Removing Oil does have the impact of halting the production of Modern Armor and the like, though.

Allowing players to obsolete their fossil fuels sounds good, but a resolution wouldn't allow them to do it unilaterally. Techs that obsolete Coal and Oil would be easy to implement, but this would be irreversible. Would also prevent the resources from being exported.

Finally, although less impactful, perhaps each Future Tech could add something like 2000 Pollution Offset, to represent large-scale carbon capture and storage. Just for an example, this could be the icon displayed on the Future Tech tech: View attachment 566277 The carbon gets captured.

I like this idea. There doesn't seem to be much that players can currently do to prevent GW from getting completely out of hand in very long games. (That icon from a WB button might be too tiny, but that's of course not a hindrance.)

While I don't want to spend much time on the GW system (and the late game in general – I don't think it's easily salvageable), I may have to look into dialing it down a bit as AdvCiv games tend to be longer than K-Mod games.

I built an Attack Submarine with the expectation that it could act as a defense for my missile-carrying Nuclear Submarines, but as it turns out, they're both exactly the same in strength.

In K-Mod/BtS, Attack Submarine is stronger, but also considerably more expensive. In AdvCiv, the costs are swapped, and I wouldn't want to give the earlier of the two units the greater combat strength.

I was hoping that there would be some way to defend the Nuclear Submarines against the easily-available Destroyers like there is in vanilla BtS, but there doesn't seem to be a way to do that with AdvCiv.

I wanted to give Destroyer a more distinct anti-submarine role. Their withdrawal chance and first strikes should make groups of submarines efficient attackers against (unescorted) Battleships though. But I can see how AI Destroyers could be too commonplace to make Attack Submarine usable; it can take quite some time to get from Combustion to Industrialism. Realistically, both Destroyer and Battleship should require Artillery.

 

[crullerdonut]

I think the probability could at most be increased to 1 permille (on Normal speed)

I was referring to the discussion from https://forums.civfanatics.com/threads/advanced-civ.614217/page-38#post-15831844 where I did a test and, during that test, nuclear meltdowns occurred far less frequently in AdvCiv compared to vanilla BtS. I certainly wouldn't want more meltdowns than vanilla BtS, where all Nuclear Plants are apparently held together with duct tape and explode frequently.
I definitely like the new commit causing an announcement where all civilizations are made aware of meltdowns. In this game, the only reason I saw that Justinian had a meltdown was that I slipped a nuclear sub into his territory and saw a bunch of fallout surrounding a city. It'd be interesting to know every time it happened.
Perhaps, if Random Events are enabled, AI meltdowns could trigger the possibility to donate in exchange for diplomatic benefit. Or maybe it wouldn't be worth the trouble.

Having to reconnect a resource temporarily in order to build railroads is silly, so I agree that it would be good to enable electric railroads somehow.

* Having the ability unlocked by Superconductors has the advantage of being simple to understand, but it has the disadvantage of happening very late in the game, maybe too late to have a useful impact. On the other hand, one usually has Oil long before this, so it should normally be possible to build Railroads without Coal fairly early. One just needs the will to lose +50% at the Ironworks.
* Unlocking the ability in the BFC of a city with power is probably not good, because players often get Coal Plants before both Railroad and Electricity. It also doesn't solve the issue of making railroads in faraway places.
* Unlocking the ability in the BFC of cities with Public Transportation has the advantage of happening at around the right time, with a tech that requires Railroad. It has the disadvantage of not allowing remote railroads. It also pretty much destroys the special AdvCiv mechanic of allowing Railroads to be built in the BFC of cities with the Standard Ethanol corporation.
* Unlocking the ability at Electricity makes intuitive sense, but it comes quite early (possibly earlier than Railroad), and again makes useless the special AdvCiv Standard-Ethanol-in-the-BFC mechanic.
* It's a shame that Industrialism already does 6 things, because I think that this would be the perfect spot to put the ability. It'd come at about the right time, and it requires Electricity as a prerequisite. I guess that one of the Industrialism effects could be moved, e.g. Ivory obsolescence to Biology or something.
* Unlocking the ability at Plastics or Refrigeration would come at about the right time, but it has the disadvantage of making little sense, flavor-wise.
* A more complicated solution could be something like the following:

1. changing "Coal Plant" to "Fossil Fuel Plant" and having it provide Power with Coal OR Oil. This would make it easier to do away with Coal, but the +50% at the Ironworks city is still tempting;
2. Coal obsoleted by Ecology;
   
3. resourceless railroads at Superconductors, to allow for earlier Oil phaseout for peaceful situations;
4. Modern Armor, etc. no longer requiring Oil at Fusion, allowing for Oil phaseout even while making military units. Not sure how this could be implemented, though
   
5. Oil obsoleted by Fusion.

The sky is the limit!

That icon from a WB button might be too tiny, but that's of course not a hindrance.

It's my understanding that the little icons in the Technology Advisor (F6) screen are loaded from art\interface\buttons\mainmenu_techscreen_worldbuilder_popups_atlas.dds, which is located in the .fpk files. This atlas is also used for the small WorldBuilder icons. That's where I got that icon from.

Spoiler :

By the way, I think that the original devs made a mistake and forgot to use this icon

for the ocean trading effect in Astronomy. They instead re-used the coast trading icon.

But I can see how AI Destroyers could be too commonplace to make Attack Submarine usable

The main thing is that by the time you have Nuclear Submarines filled with Tactical Nukes, the AI will surely have swarms of Destroyers ready to blow them out of the water. Maybe Nuclear Subs could have 30 and no first strikes (but still 50% withdrawal chance) to be able to defend themselves against Destroyers. Or maybe for the purposes of launching Tactical Nukes, one shouldn't have any expectation that they will survive the following turn: in that case, maybe they should be "glass cannons" which get killed immediately after the nuclear exchange, but in that case, maybe they should hold more nukes.

There's a lot of fun things to think about.