Civ4 AI Survivor Season 4: Playoff Game One Writeup

Our first playoff game of Season Four featured an absolutely stacked field of competitors. This group included three of the top six leaders in our overall ranking, as well as the top two leaders in Season One champion Justinian and Season Two champion Huayna Capac. Both of these leaders had dominated their opening round games, and their showdown in this match would be something to watch. They were joined in this match by Kublai Khan, the sneaky-good Mongolian leader who reached the championship game in two of the first three seasons of AI Survivor, and Hannibal, one of the strongest performers over the last two seasons. Either of those two leaders would have likely been the favorite in other matchups with weaker competition. Finally, this game also included the surprising winner of the first game of Season Four in Isabella, and the equally surprising runner up from Game Two in Willem. Each of these leaders had done very poorly in previous seasons, and this was their chance to make a splash on the big stage.

This game opened up with a three-way religious race between the leaders who started the game with Mysticism tech. Justinian chose to go after the more expensive Polytheism tech and was able to establish Buddhism with no issues. Isabella and Huayna Capac had both gone after the cheaper Meditation tech, however, and only one of them could land the religion. They both discovered the tech on the same turn and Isabella won the tiebreaker by virtue of being first in turn order. She picked her expected Christianity as the resulting religion and Huayna Capac would be locked out for the moment. He would later prioritize Monotheism tech and found Confucianism although not until the later date of Turn 44.

With land at a premium on this smaller continent, the location of the initial starting Deity settlers and the worker management of the AI capitals would be more important than ever. All six of these leaders chose to settle towards the center of the map, none of them wasting their starting settler on tundra wastelands, however many of these second cities were buried in the equatorial jungles and wouldn't be terribly useful in the early game. Some of the leaders had starting techs that matched the resources at their capital or quickly researched the worker techs that they needed. Kublai Khan did a nice job of hooking up his ivory and gold resources for +2 happiness at his capital, and Willem also improved his rice, ivory, and gems resources in rapid order. Other leaders focused on religious techs and had a slower start out of the gate, especially Justinian and Isabella. They both had poor starting techs and compounded the situation by chasing after religions before researching worker techs. In their defense, both of them did win their respective religious races and that could pay dividends later on.

Most of the leaders had expanded out to four or five cities by Turn 50. It was quite a contrast to the barbarian-choked opening that we had seen the previous week in the Wildcard game. Justinian had the most cities at five after double expanding, and he probably expanded a bit too quickly because he had managed to crash his economy in the process. Hannibal was also expanding quickly without researching any techs that provided culture, no Mysticism or Writing for him yet, and as a result none of his cities could expand their borders. Kublai Khan had surprisingly built Stonehenge, a wonder that he didn't need with his Creative culture, and didn't seem to be expanding out beyond three cities while instead pausing to build more military units. We assumed that these units were intended for the barbarian city that had spawned in his back lines. Kublai had also converted to Justinian's Buddhist religion by this point and he had reached Iron Working tech at a very early date. Further to the east, Isabella was in the process of building the Oracle (which would turn into Monarchy tech) while Willem had already constructed the Great Wall and was heading towards the Pyramids.

Now Kublai Khan had been the early research leader thanks to having three gold resources at his capital city. His tech preferences are militaristic in nature and Kublai decided to rush for first Bronze Working, then the aforementioned Iron Working. The second Mongol city from the free Deity settler turned out to have iron present and thus Kublai had iron connected for swords before Turn 50, extremely early even for Deity civs. Evidently Kublai saw this as the golden opportunity to make a move as he declared war on Justinian on Turn 52. This was one of the earliest war declarations in Civ4 AI Survivor history, and might have actually been the early war we've ever seen. Justinian was caught completely off guard by this move; he had largely crashed his economy with rapid expansion and he'd been slow to connect any resources at his capital by virtue of his poor starting techs and initial Poytheism research. He was not prepared to stop Kublai's attack and the Buddhist Holy City was captured immediately:

This was a disaster for the many people in the picking contest who had chosen Justinian to finish first or second. My expectation had been that Justinian and Kublai would pair up over shared religion to dominate the game; instead, Kublai had completely ignored the Byzantine religion that spread into his territory to launch this ultra-early invasion. And the news kept getting worse still for Justinian here. Check out his research: 16 turns to Bronze Working tech! This meant that he had no metal resources at all plus Justinian couldn't even whip units via Slavery civic. He also lacked horses anywhere in his territory and therefore couldn't build chariots. But wait, it was even worse than that. It turned out that Justinian also didn't have Archery tech yet so no archers either. All of this meant that Byzantium could build exactly one military unit: warriors. And they had to stop axes and swords. Good luck with that guys.

Kublai took a few turns to regroup and assemble a new stack. He peeled off one axe that wandered over to Antioch and autorazed it, easily winning the axe vs warrior matchup. That city had only been two turns away from growing to size 2 and it was a bit unlucky on Kublai's part that the city had been autorazed. The main action was taking place at the Byzantine capital city of Constantinople though, where Justinian had a single archer (one of the free starting Deity archers) and three or four warriors on defense. It looked for sure that the capital was going to fall to the invading Mongolian swords and axes, which would essentially eliminate Justinian from the game. The fighting outside this city was furious for half a dozen turns on end, Kublai's units winning their battles and promoting while Justinian kept cramming more warriors into the city. The archer survived one round of combat with 0.1 health left, and on a subsequent turn Constantinople had a single warrior with 1.4 health remaining and nothing else. But it turned out that the defenders had just barely enough to hold here, lasting until Justinian could finish researching Bronze Working tech and connect the one copper that he had in his territory. Once Justinian had copper connected, he upgraded his warriors to axes and that was enough to stop any hope of his capital falling.

This was extremely close and Kublai appeared to have gotten some unlucky dice rolls at crucial points in time. A single Mongolian unit winning instead of losing would have been enough to change the result. Alternately, if Constantinople hadn't been located on a hill tile, the city definitely would have been captured by Kublai. The two sides did eventually sign peace on Turn 79 with no further cities changing hands. The net result of this war was Kublai capturing the Buddhist Holy City and confining Justinian into his starting corner of the map. The Byzantines were finished as a power by this point, much to the disappointment of the picking contest.

While that war had been raging on the western edge of the map, the other four leaders had been building peacefully. Willem finished the Pyramids followed by the Hanging Gardens, making use of the stone resource at his capital, and the various leaders who had founded religions picked up Great Prophets for their respective shrines. The religious diplomacy was beginning to take shape in this game, with Willem picking up Isabella's Christianity while Hannibal converted to Huayna Capac's Confucianism. Kublai Khan and Justinian both shared Buddhism, and despite their early war the shared faith was patching up relations between the two of them. The leader on top of the scoreboard at this point was Willem, who had the best economy and had picked up a solid amount of territory by expanding to the north. Isabella had been slow to expand up there and the Dutch managed to claim enough land for about ten cities. Huayna Capac was also doing quite well in terms of research despite having a smaller amount of cities, and the potential was there for the Incan leader to team up with Hannibal and form their own religious alliance, therefore emerging as a major power bloc.

Despite that early invasion, the game had been surprisingly peaceful overall. The peace was eventually broken when Huayna Capac decided to attack Kublai Khan on Turn 94. This was a puzzling decision to say the least; they had a similar peace weight and Isabella was the "worst enemy" of the Incans up to the north. In fact, Isabella was the "worst enemy" of several different leaders due to her polarizing Christian faith, and yet no one attacked her in the early game as many of us had been expecting to see happen. It looked like Kublai had been gearing up to fight Isabella when this war broke out, only for any such attack to be called off. Instead the Mongolian army headed off to the east to clash with the Incans, and the border clashes did no go well for the guys in yellow:

Huamanga was the first target to fall and there wasn't a whole lot behind that on the part of Huayna Capac. He had only managed to found seven cities in total and losing any of them was a major blow. Kublai Khan had access to Construction tech now, unlocking war elephants in the process, and this meant that catapults would be available to remove the defenses of the Incan cities. Huayna Capac needed someone to help him out but there didn't seem to be anyone interested in joining the war. Willem was continuing to build key economic wonders in the form of the Great Lighthouse, Colossus, and Sistine Chapel, while Justinian was more interested in finishing the Apostolic Palace than looking for a war of revenge against the Mongols. That wonder was a boost for Kublai Khan who easily won the Buddhist election that followed. He made his best effort to get the rest of the world to join him in his crusade against the Incans:

However, Justinian wasn't interested in going to war and he had enough votes to block the resolution from passing. Ironically, it probably would have been better for Justinian and Isabella if this AP resolution had passed, as it would have offered them as chance to pick up additional territory and gain "mutual military struggle" diplo points with the Mongols. Instead, Isabella launched her own attack against the weak remnants of the Byzantines. She captured the border city of Nicaea and eventually took the capital of Constantinople, with Justinian looking likely to win the First to Die prize. However, Kublai voted through a "stop the war" resolution in the Apostolic Palace that shut down that particular confict, leaving Justinian with exactly two cities remaining. It would have been better for Kublai if Isabella had finished off Justinian, as he would have absorbed most of the Byzantine cities via his culture afterwards. He did pick up the former Byzantine capital where his own attack had fallen short earlier in the game. Somehow, someway, Justinian remained alive for the moment.

That was more than could be said for Huayna Capac. No one ever intervened in the lengthy war between the Mongols and the Incans, with Kublai methodically capturing one Incan city after another. It didn't help that Huayna Capac kept building additional wonders during the course of this war, such as the Mausoleum that Kublai was happy to take off his hands after it finished. Eventually it was all over and the mighty Incans were removed from the board on Turn 158:

This was a game where Huayna Capac was never quite able to get things rolling along due to a combination of weaker land and poor diplomacy. He was not able to get his religious ally Hannibal to intervene and change the course of the war, and the rest of the world had largely stayed peaceful while the Incans were slowly rolled up one city at a time. Kublai Khan emerged from this conflict as the territorial leader of the game, and normally picking up a solo elimination would be enough to snowball him into the dominant AI position. However, Kublai had been doing so much fighting that even absorbing all of the cottage-rich lands of the Incans wasn't enough to make him the tech leader. That position was held by Willem, who had been making excellent use of his Financial trait to reach almost all of the first-to-discover prizes on the tech tree along with building most of the game's Medieval and Renaissance era wonders. Kublai had also failed to capture the barbarian city in his backlines while all this warring was taking place, leaving it to be taken by the Dutch and creating a dot of orange on the minimap in the far southwest. It was a real question now as to which would be stronger in the long run: the greater size of Mongolia or the better teching of the Dutch.

It was honestly kind of shocking how peaceful the eastern part of the map had been. Hannibal in particular had done essentially nothing despite practicing a different religion from both Kublai Khan and Willem. Eventually Hannibal did invade Willem but not until Turn 148, and although he did manage to capture the border city of Utrecht, it wasn't enough to put a serious dent into the Dutch economy. When they signed peace two dozen turns later, Hannibal gave back the captured city since it was completely surrounded by Dutch territory. If the goal was to stop the tech leader from running away with the game economically, Hannibal wasn't doing a very good job of it.

Meanwhile, Kublai had decided to continue his pursuit of a Domination victory by declaring war on Isabella. He had some AI pathfinding issues whereby a stack with about 100 units in it stood in place without moving for half a dozen turns, but eventually they got in gear and went after the Christian Holy City of Barcelona. This was the site of very heavy fighting on both sides, as Isabella defended the city with about 50 units of her own against that giant Mongolian stack mentioned earlier. The siege of the city lasted for long turns on end with both sides hurling more and more units into the fray. There were Mongolian maces with City Raider III + Combat I + Shock promotions by the end of the brutal melee. When the dust finally cleared, the Mongolians had captured the city at a heavy cost on both sides.

Hannibal's power was also spiking on the bar graphs and he joined the conflict short time later on Turn 207, taking advance of this opportunity to pounce on the weakened Spanish. Isabella was exhausted from the siege of Barcelona and she was in no position to face off against two different leaders at once. Any attempt that she might have made to induce Willem to help out was in vain, as he continued to stay on the eastern side of the map and race through the tech tree. The result was a partition of the Spanish lands between Kublai and Hannibal, with each of them getting about half of the territory. In truth it was probably more of a three-way split of Spain since Willem would end up scoring all of the cities along his border due to the dominance of Dutch culture. In any case, the war lasted about three dozen further turns and concluded with Kublai landing the killing blow on Turn 234:

The community had overwhelmingly made Isabella their choice as First to Die in the picking contest, with about 75% of the contest entrants choosing her to leave the game first. Even though that didn't wind up happening in this game, the community had the right idea overall. Isabella made enemies of everyone else with her religion and it was only a matter of time until that came home to roost. If it hadn't been for Kublai launching his early attack against Justinian, and if Huayna Capac hadn't started his own war when Kublai was gearing up for a likely attack against Spain, we likely would have seen Isabella gone from the field much sooner. This is the game that I'm most interested in replaying after the season ends to see how it would look differently with Preserve Random Seed turned off. I suspect that we'd have some different results than what we saw here.

Anyway, Kublai Khan was now the dominant territorial leader with about 40% of the world's land mass. He had conquered all of the Incans and roughly half of the Spanish. In most games, he would be the runaway AI leader and a sure favorite to win. There was just one problem in this game:

Oh yeah. That problem. Willem had been at peace for nearly the entire game, aside from 30 turns of inconclusive warring with Hannibal with no cities ultimately changing hands, and this was what almost 200 turns of uninterrupted Financial economic development looked like. The Dutch economy was well above Mongolia and Carthage on the bar graphs (to say nothing of poor Byzantium) and then kept getting further and further ahead. Willem already had the Statue of Liberty and the Pentagon finished, with factories and power plants established across the Netherlands, while Kublai and Hannibal were still back in the rifles and cavalry Renaissance period. Despite the vast territorial advantage of the Kublai + Hannibal alliance, it was unclear that they would be able to have much progress against Willem if it came to a war. And if it didn't come to a war, the Dutch were a lock to win via the space race since Willem was more than a full era ahead. We always talk about how Civ4 is a game where tech ultimately dominates, and this was a powerful example of that old dictum.

It turned out that we were not going to get a peaceful ending in this game. Willem was the one to initiate hostilities, declaring war against Hannibal on Turn 239. I guess that this was an attempt to get revenge for the earlier Carthaginian invasion, and Dutch infantry and artillery pieces began to capture the cities along their respective border. The one and only hope for Hannibal was a joint war with the Mongols, and Kublai delivered on that promise about a dozen turns later:

This was the ending that we were hoping for: the Kublai + Hannibal alliance taking on Willem in a 2 vs 1 situation. If they weren't going to win the war now, they were never going to be able to dislodge the Dutch powerhouse in the east. And they had to do it quickly because Willem was researching Industrialism tech, which would unlock tanks and make any combat significantly more difficult. Hannibal had reached Assembly Line tech and had access to his own infantry and factories, but Kublai was still a good distance short of that generation of military technology. The Mongols were all rifles and cavs, units that would be brutally slaughtered as soon as tanks appeared. Kublai had to make his mark right now.

The war got off to a good start for the Mongols. Kublai had about 100 units in the city of Murcia where they had been trapped by a lack of Open Borders with Willem, and that stack headed east and captured the city of Middleburg almost immediately. There was fierce skirmishing all along the lengthy Dutch border, with Mongol and Carthaginian units doing their best to capture the Dutch territories. Then we were thrown for a loop: Willem suddenly decided to turn off his teching and go 100% culture! This was a really stupid decision as he could have won via space much faster than via culture, and in fact one of his top three cities from a cultural perspective had been Middleburg, which had just been captured. It looked like Willem would need roughly 70-80 more turns to get three cities to Legendary status, time that the other two leaders could use to catch up in research. What was Willem doing?!

However, even with his science turned off, Willem was far enough ahead that his units were dominating the battlefield. Once the tanks arrived, they began terminating the Mongol horses with extreme prejudice. Just look at the Power bar graphs as the war ground onwards:

The Dutch were doing better and better the longer the fighting continued. They were simply winning the 1 vs 1 unit matchups due to superior technology, and factory production allowed the units that perished to be replenished faster despite having fewer total cities. Seeing the writing on the wall, first Hannibal peaced out with a treaty on Turn 265, then Kublai followed on Turn 274. Middleburg was recaptured during the fighting and Dutch workers began the process of rebuilding its tile improvements to get the culture flowing once again. We clicked through a bunch of turns waiting to see if anything would happen as Willem slowly crept closer to his cultural victory. Kublai decided to have another try at Willem a little while later:

But despite the intervening time, the situation was still essentially the same as before. Kublai had inexplicably refused to research Assembly Line tech, picking up seemingly everything else in the early Industrial period instead, and thus his military was still dependent on rifles and cavalry. Willem's tech had not advanced either because he had been on 100% culture the whole time, however that didn't matter because he still had plenty of tanks and artillery and bombers. The more advanced Dutch military slaughtered the Mongolian horses once again, and that was that. Even Hannibal joining the war to create a fresh 2 vs 1 situation had no effect. Willem was simply too far ahead technologically at this point. He wasn't gaining territory for himself because he was so badly outnumbered, but he had more than enough to defend his own cities.

In desperation, Kublai Khan called for a Diplomatic Victory vote in the United Nations:

And he came 13 votes short of winning. Missed it by that much! This was quite literally the difference of a single city, and if Kublai had managed to take and hold even one Dutch city the result would have been a Mongol victory. Or if Kublai had captured that barbarian city in his backlines - which he had walked past with a pair of swords without attacking earlier in the game - he also would have won this vote and the game. Justinian could have played kingmaker here and also cast the deciding votes; he ended up getting his revenge for that very early invasion by denying Kublai the win. Or the Mongols also could have won by simply calling this vote earlier, back when Kublai was holding the captured Middleburg, instead of calling a whole bunch of votes on nonsense like Environmentalism civic and Single Currency. Kublai controlled almost half the map and had led in score for virtually the whole game, but this was't going to turn into a victory for him.

Instead, Willem eventually generated a Great Artist and detonated the resulting culture bomb into his city of Middleburg, triggering the Cultural victory on Turn 344:

This game truly demonstrated the power of a strong economy. Willem was left alone for most of the game and that proved to be enough in the end, with his research hitting critical mass and making him essentially invulnerable to attack. Even sitting at 100% culture for the last 75 turns of the game wasn't enough to make a difference, as Hannibal and Kublai still weren't able to catch up in tech before the cultural victory arrived. Reverent from the picking contest had an extremely accurate prediction along these lines from before the game started that I want to highlight here: "Once he hits the midgame, Willem's highly reminiscent of Victoria and Gandhi in that he refuses to build units and research military techs. If he manages to research Rifling without losing his core cities, he's set. His strong tech edge will save him from there. However, if Willem is attacked by someone while he's busy messing with Communism while avoiding Gunpowder, then he'll have shot himself in the foot. With an arrow. If he makes it past this point, he'll be fine. He'll go on to win a cultural victory." This was exactly what happened - an amazingly good prediction. (Kudos as well to Aus prof who wrote a similar version of the same prediction tabbing Willem to win!)

This game was most reminiscent to me of Game Six from the opening round, where Darius pulled off a similar economic-focused victory condition and simply became too far ahead in tech to lose. We always need to remember that the Financial leaders have the chance to pull this out of their back pockets. They don't necessarily need the most territory to win the game, just time enough to be left alone and out-tech the rest of the field. In any case, Willem will move onto the championship game and Kublai Khan will get another shot at him there as the runner up. We'll see how things play out in their rematch in a few weeks.