Civ4 AI Survivor Season 3: Game Four Writeup

Game Four was a return to the larger field of seven AI competitors. This game featured two particularly heavy hitters, with the strongest community preference going to Catherine of Russia. Over half of the entries in the picking contest chose her as the expected winner, and among those who didn't pick her to win, another 20% of the respondents had Cathy finishing second. The Russian tsarina had been the outright winner of two games in past seasons, while picking up an impressive five kills in the process. Her rapid expansion and willingness to declare war on essentially anyone always makes Cathy a strong competitor in these games. The other top pick with Justinian of Byzantium, the Season One champion of AI Survivor. He had an excellent starting position at the top of the map, and the community had identified him as the clear second place choice in this match. Justinian and Catherine had been in the same game two times previously in past years, with each of them winning one of those matches. This would be their third clash and potentially the decider in their ongoing competition.

There was considerably less community support for the other leaders in this game. Darius and Roosevelt both had good economic traits, but their proximity to Cathy made their prospects somewhat dubious. Darius in particular should be good at these AI Survivor games given his Financial/Organized traits and the generally solid Persian civ, however he's repeatedly disappointed us in past years. I was picking him as First to Die largely due to that past history. The east had Saladin of Arabia, who is one of the game's most religiously inclined leaders, and Louis of France, an oddball personality that mixes together high aggression with a strong preference for wonder building. That combination generally hasn't worked too well in past years. Finally, we had Montezuma drawn into this game in the northeast corner of the pangaea. Monty is arguably the game's most insane leader, combining the overaggressive tendencies of Shaka and Genghis Khan together with the religious zealotry of Isabella. He was the top community pick for First to Die, and that seemed a likely outcome. It's impossible to predict what Monty will do; all that anyone can say ahead of time is that he'll spread chaos and destruction wherever he goes.

This game began with a fierce race for the initial two religions. Justinian, Montezuma, and Saladin all started with Mysticism tech and wanted their own faith to spread around. Justinian and Montezuma both went for the Meditation religion while Saladin chased after the Polytheism religion. The net result was Justinian narrowly beating out Montezuma to found Christianity, while Saladin took an uncontested Islam for himself. The Aztecs were surprisingly locked out of an early religion. I thought that Monty would go after the Monotheism religion and get his own faith that way, but instead it was Catherine who was the first one to head down that path and found Judaism a bit later on Turn 43. This would leave the game with three major religions: Byzantine Christianity in the north, Arabian Islam in the south, and Russian Judaism in the west.

The early expansion played out mostly as expected without anything too stupid taking place. The second cities with the initial starting Deity settlers generally went in logical spots, with Cathy picking perhaps the worst location by heading south along the west coast. Saladin placed his second city due west towards Darius, and when Islam popped in there it became the Holy City and would end up stealing a lot of territory in the disputed area between their civs. Monty planted his third city to the west and settled it on top of Justinian's own Holy City, in a move that seemed destined to cause conflict between the two of them. Elsewhere Louis was being stymied by a barb city that sprang up to his south, although he was able to get a decent cluster of cities in the area surrounding his capital. Darius was starting to get hemmed in between the Creative culture of Cathy to the west and the Holy City culture of Saladin to the east. Roosevelt was the slowest to expand and looked to be getting coralled into the northwest corner, with dwindling opportunities for further territorial gain. If anyone was doing the best it was likely Justinian, who had established a series of cities in a line towards the center of the map, like Hannibal had done in the previous game, and still had room for additional tundra cities in the north to fall back on later.

Montezuma had actually built Stonehenge, of all leaders, and that was helping him culturally in his portion of the map. Two barbarian cities had also popped up in the center of the continent, and it would be critical to see which of the AI leaders would be able to claim those spots. There were also peace weight considerations at work here as the diplomatic aspect of the game began to take focus. The high peace weight of Roosevelt was already creating problems for him, as he somehow found himself targeted as the "worst enemy" of Catherine, Louis, Montezuma, and Saladin. For someone who was already getting stunted on land, this did not bode well for the future.

If we had been running a contest to guess who would start the first war, Monty would have been the runaway choice. To no one's surprise, he got things started by invading Justinian on Turn 64:

Oh Monty. Don't ever change man. The Aztecs were under serious cultural pressure from the Christian Holy City of Thessalonica, and that was the likely trigger for this conflict. (Other than Montezuma being completely insane, of course.) The Aztec city of Tlatelolco had sniped away a key horse resource on the border, but Justinian had managed to settle another one by winning the race to a spot on the west coast near the American border. Justinian was also about to complete the Oracle and pick up Metal Casting at an early date, with the forges synergizing well with the gold resources he had near his capital. In military terms, this attack went just as poorly as one would expect, with axes and chariots achieving precisely nothing against defenders holding behind 40% cultural protection. Neither combatant would be able to achieve much here until Construction tech brought siege units into the mix.

The next major development took place in the west, where Catherine initiated an early war of her own against Roosevelt:

One of the key questions for me going into this game was whether Cathy would go after Roosevelt or Darius first. Both of those leaders have the same high peace weight score of eight, and as a result it mostly came down to luck as far as which one she would target. (It was obvious that Cathy would attack one of them; this is Cathy we're talking about here.) Roosevelt appeared to have drawn the short straw, and this made him a strong favorite to be the First to Die in this game. The problem for Cathy is that this was too early in the game to mount an offensive. She would have been better served to continue expanding down into the tundra and tech up towards Construction to take advantage of her ivory resource. The American border cities all had walls or heavy cultural defenses which would rule out any gains until catapults showed up. As a result this war largely ended up as a stalemate, with Catherine taking the barb city of Gaul but failing to make any other territorial conquests. The two of these leaders signed peace on Turn 88 with a return to the status quo antebellum. This represented a bit of a missed opportunity for Russia, which would have been better served by attacking later with a larger force.

While these two wars were ongoing, the diplomatic landscape of this game was beginning to clarify. Catherine sent several Jewish missionaries on a long march to the east, with the net result of converting Montezuma to Judaism. This formed a potentially terrifying tagteam of Cathy and Monty, who might be strong enough together to purge the continent of everyone else. In the south, Islam spread naturally to nearby Persia and Darius converted to the religion, forming a two nation religious block in the south as well. Justianian's Christian missionaries then spread his faith to Louis' France and converted him as well, forming yet another two nation block. The overall result was a Russian/Aztec Jewish pairing, an Arabian/Persian Islamic duo, and a Byzantine/French Christian partnership. Only Roosevelt remained uncommitted to any of these religious groupings as yet.

Once the religious affiliations were lined up, the war declarations began to fall along these religious divides. Saladin invaded Louis on Turn 85, in a conflict that would see heavy fighting around the French border city of Marseilles. That location had been settled on a hill and contained walls for the +50% defensive bonus, which would turn repeated attempts to conquer it into a slaughterhouse. No territory would change hands in this particular conflict. Up in the north, Justianian eventually teched up to Construction and used his catapults to break through the Aztec lines at Tlatelolco. Rather than push further into Monty's core, Justinian opted to sign peace on Turn 100:

This was a key moment in Game Four. Justinian was the game leader at the time, and he could potentially have continued to attack the weaker Aztecs until they were eliminated. Instead, Justinian stopped with one city taken and went back to peaceful development for a while. His early completion of the Christian shrine was a major help here, continuing to supply the Byzantines with gold to fuel additional research. Christian missionaries would spread out like a plague over the next dozen turns to convert more and more foreign cities to the faith. Justinian would also build the Apostolic Palace during this peaceful interlude on Turn 112, which would have major ramifications later. With Justinian no longer expanding, Catherine would soon catch up in score, and the two game favorites began going at it neck-and-neck for top place on the scoreboard. This was what we had been expecting before the game started, and it was great fun watching the two of them compete.

As for Montezuma, he stayed at peace for all of ten turns before launching another war by declaring on Louis. This created one of those unfortunate 2 vs 1 scenarios for the French, and now it looked like Louis might be the first to be eliminated from this match. However, Creative culture ensured that all of the French border cities were well defended, and Darius decided to invade Montezuma on Turn 116, which relieved much of the pressure on Louis. The result of all this was a confusing mess of wars in the southeast corner of the pangaea, with France and Azteca both involved in two-sided wars in various combinations with Arabia and Persia. Darius was able to take exactly one city, and otherwise there was little in the way of territorial conquest.

Meanwhile, both of the game leaders were ready to go back on the offensive again. Catherine renewed her war with Roosevelt on Turn 119, this time with catapults in hand and more than half again Roosevelt's score on the leaderboard. To counter her aggressive, Roosevelt had built Chichen Itza before the war began (+25% defense in all cities), and this would have a major impact in terms of slowing the Russian advance. Justinian was also ready to fight once more, and it was time to lay the smack down on...

Darius?! Talk about an unexpected move. The logical choice here would have been an invasion of the Aztecs, claiming revenge against Montezuma for the earlier attack and going after an enemy religion in the form of Judaism. Byzantium and Azteca also had a huge shared border that had to be causing a lot of diplomatic tension. Instead, Justinian went after Darius, who also practiced a foreign religion but had almost no shared border at all with Justinian's empire. What was going on here? As best I can tell, this was simply one of those luck elements that can't be predicted ahead of time. A roll of the dice, a quirk of AI programming, who knows. For whatever reason, Justinian decided that he wanted to attack Darius instead of Montezuma, and this would have a drastic impact on the rest of the game. Take a look at the religious icons in that picture above. Justinian had converted both Louis and now Roosevelt to his Christian religion. He decided to make use of those conversions by wielding the power of the Apostolic Palace:

Louis and Roosevelt were forced into the war against Darius by virtue of the wonder, leading to the crazy mashup of diplomatic relations pictured above. The Persians had earlier started a war with Montezuma, then were declared on by Justinian, then saw Louis and Roosevelt pulled into the same conflict to create a nightmarish four-way conflagration. The biggest beneficiary of this development was likely Monty, who was now largely in a single conflict against Louis... while also allied with Louis against Darius. Very confusing. Roosevelt also wouldn't be sending any units against Darius by virtue of his much larger conflict with Cathy. In practice, Darius only had to deal with Justinian but that would be a tall order on its own. Justinian would also benefit diplomatically from a lot of mutual military struggle bonuses with his three mostly unwilling wartime allies against Persia. This would have longstanding effects on the diplomatic front for the rest of the game.

In her separate war, Catherine was able to make a breakthrough and capture the city of Philadelphia on Turn 130. This was her biggest success in this particular conflict, and it reduced Roosevelt to a mere five cities remaining. Cathy also had the city of New York under siege, and that was a particularly important target because it contained Chichen Itza, the wonder that was doing so much to slow down the Russian invasion. In fierce fighting, Cathy was ultimately unable to capture New York before signing a new peace treaty with Roosevelt on Turn 143:

America would live to fight another day as a rump state. Cathy's failure to eliminate Roosevelt at this point in the game would prove to be highly significant down the road. I think that if New York hadn't been established on a hill tile, it would have fallen here and that might have greatly changed things. There are two other things to note in this particular screenshot. One was Roosevelt's completion of the Hindu shrine; he had founded the religion earlier in the game but hadn't swapped to it, preferring to remain with Christianity. If Roosevelt were ever to change his religious affiliation, he would find himself in a position of diplomatic peril. Secondly, note the religious icon for Montezuma in the corner of the screen. The Aztecs had swapped from Judaism over to Christianity, thus bringing Monty into Justinian's diplomatic camp. With the two of them also unexpectedly fighting a joint war against Persia, their diplomatic relations would begin to soar. Amazingly, the Byzantines and Aztecs were in the process of becoming allies in this game, despite the hostilities at the beginning of the game. I did not see that coming after the way this game started out, let me tell you...

The southeast corner of the map remained in a state of constant warfare, with alliances shifting back and forth almost faster than I could keep track. Louis signed peace with Darius but then Saladin declared war on Louis, followed by Monty signing peace with Louis as well. Slowly this area was shaping up into a shared Christian struggle against Saladin's Islamic faith. Increasingly, the non-Christian civs were the outsiders in the diplomatic picture, and they were beginning to be isolated from the rest of the world.

But the most significant thing taking place in the game was Justinian's continued slow offensive against Darius. He started out by taking the former barb city of Polynesian and the captured Aztec city of Tlaxcala. Then the Byzantines initiated a methodical march through the Persian core cities, beginning with Susa (home of the Pyramids) in the north and continuing on towards Persepolis, which fell on Turn 162:

The surprising thing was that Justinian wasn't doing this with his amazing cataphract unique unit. For inexplicable reasons, Justinian avoided researching Guilds for the longest time even as he went after all sorts of Renaissance techs elsewhere on the tree. As a result, this was a slow but steady process of conquest with elephants, maces, trebuchets, and catapults. Darius went through a lengthy period of collapse over dozens and dozens of turns; there were ample opportunities for other leaders to intervene, either stopping the invasion or accelerating it, and no one did so. Justinian was single-handedly stomping through Persian territory and collecting all of the spoils for himself. As a result, slowly but inevitably he began to emerge as the game's score leader as more and more territory passed into Byzantine hands.

Elsewhere, the Aztecs and French decided to join forces to fight against Arabia, with Monty jumping into the ongoing Saladin/Louis war on Turn 162. Saladin was stronger than either of the other two civs, however their combined power was enough that the Arabian forces began to be slowly grinded down over time. This was another war that would continue for an extended period. Cathy decided to get back into the action as well by declaring war on Roosevelt for the third time on Turn 174. This time she was able to punch through and capture the American capital of Washington, her biggest triumph yet. With that said though, Cathy's position in this game was deteriorating rapidly. She remained wedded to her self-founded Jewish religion, and in an increasingly Christian world that was a dangerous position from a diplomatic standpoint. In big picture terms, Cathy simply hadn't managed to conquer Roosevelt quickly enough. She needed to eliminate Roosevelt before Justinian could eliminate Darius, and it was becoming clear that wasn't going to happen. Chichen Itza had been a thorn in her side ever since the beginning of the second war against America, and looked to have been one of the key wonders in this game (along with Justinian's use of the Apostolic Palace). When Catherine signed yet another peace treaty with Roosevelt in exchange for another city, it was an ominous sign.

As for Darius, he was never able to stop the progress of Justinian's army. Montezuma jumped in and poached one of the last remaining Persian cities, but everything else went to Justinian. He claimed the killing blow on Turn 194:

Thus my prediction of Darius as First to Die had been correct, albeit in a completely different fashion than expected. I thought that Cathy would conquer Persia and snowball from there into a Domination victory while Justinian and Monty fought each other on the top side of the map. Instead, Justinian had been the one to conquer Persia while Cathy fought a somewhat successful series of wars with Roosevelt, and Justinian had somehow managed to pull off the diplomatic coup of turning Montezuma into an ally. How the heck did that happen again?! In any case, Byzantine territory now bisected the continent from north to south. Justinian will not declare war at "Pleased" relations, and he had those relations or better with all of his Christian allies. The big question was whether he would choose to target Cathy or Saladin for his next attack. Both Montezuma and Louis were at war with Saladin again (the trio of them had been fighting on and off repeatedly for the last fifty or so turns), and the odds seemed good that Justinian would join them in a joint conquest of Arabia.

Instead, he decided to go after bigger prey and invaded Catherine on Turn 217:

Usually I can catch the war declaration in a screenshot, but this time I missed it. The attack came against the Russian city of Gaul, that former barb settlement that Cathy had picked up early in the game. The timing was excellent for Justinian, as he had just finished researching Rifling tech and was in the process of upgrading his cuirassier force into cavalry. Catherine had her own cuirassiers but she lacked Rifing tech, and that would make a huge difference here. Furthermore, she had a brain fart with her further research and chased all the way down the tech tree to Communism, ignoring the need for rifles and cavs for defense. This had immediate negative effects across her empire. Justinian began by slicing off the northern line of Russian cities at Yekaterinburg and Rostov, then headed north and began running over Catherine's American conquests. One by one the cities fell without much in the way of Russian resistance. Justinian's power was increasingly off the charts on the power scale, and there was no answer for his factory-powered swarms of cavalry. When we saw this stack gathering outside Moscow, we knew that Cathy was well and truly doomed:

Why yes, that's 40 rifles and 62 cavs joined together on that tile. Oh, and Justinian was also now using artillery units as well. They were shredding Cathy's cultural defenses and inflicting terrible collateral damage, while surviving to live and fight another day. Rifle defenders are essentially helpless against attacking artillery. This was ugly for Catherine and getting uglier with each passing turn.

Things weren't much better for Saladin off to the east. He was in the process of getting dogpiled by all of the other Christian leaders in the game, with Roosevelt joining in the fray alongside Louis and Montezuma. Saladin was stronger than all of his opponents, and he had built some key wonders including the Taj Mahal and the Statue of Liberty. I'm still not sure how he was able to get the latter wonder instead of Justinian. This three-way invasion was akin to a bunch of minnows working together to pull down a shark. It also demonstrated the power of religion in this game; this was an AI Survivor match that had swung heavily along lines of faith. Weak leaders like Roosevelt and Montezuma were still surviving largely because they had managed to adopt Justinian's dominant Christian faith. Cathy and Saladin had far outplayed both of them in this game, but they were heading out the door because of their rival faiths. When the big dog in a particular game is a religious maniac like Justinian, it seems that it's a good idea to follow whatever religion he happens to be practicing.

The Russians were finally eliminated on Turn 267:

That marked the first time that Cathy had actually been killed in any of our three seasons of AI Survivor, a real rarity at this point. Her failed invasions of America and her self-founded religion proved to be her undoing in this game. Meanwhile, with the incorporation of the Russian territories, Justinian now ruled over a vast portion of the map. He had already passed the population requirement for Domination and was sitting at about 55% out of a needed 62% on the land requirement. Saladin's territory might be enough to get him over the hump for a victory. Failing that, the land of any of the other civs certainly would be enough for Domination. Keep in mind that Justinian won't declare war at "Pleased" relations though, and therefore it seemed unlikely that he'd start a war with any of his religious compatriots. The best chances for more action would likely come from someone swapping into Free Religion civic or Montezuma doing something insane. It wasn't out of the question that he would invade Justinian after Arabia was gone, not with "Aggressive AI" checked for this game.

As the last few Arabian cities began to fall to the combined French/Aztec/American armies, there was a sudden development that took place diplomatically. For some inexplicable reason, Roosevelt decided to swap his religion over to Hinduism:

I had to pull that screenshot from the Livestream footage because I didn't manage to capture it at the time. I guess that Roosevelt had finally managed to finish spreading Hinduism to all of his cities, and since the AI always has a preference for its own self-founded religions, he decided to make the change. However, given the geopolitical context of the wider world, this was one of the most suicidal decisions that I've ever seen an AI leader make. Justinian had over 50% of the entire world under his control and was closing in on triple Roosevelt's score on the leaderboard. In terms of purely military strength, the Byzantines had something like 25 times the power rating of the Americans. Roosevelt should have been kissing Justinian's boots and doing anything possible to avoid displeasing him. Instead, this religious swap lowered relations between the two civs by about a dozen points, going from +7 from shared religion to -5 from competing religions. Now Justinian was suddenly "Cautious" with Roosevelt, and with the Byzantines so close to reaching Domination, it looked like only a matter of time before Justinian brought the hammer down. Sure enough, just a dozen turns later on Turn 285 the war horns blared and the Byzantine tanks rolled across the border. The only remaining question was whether Roosevelt would manage to survive long enough so that he was still standing when the inevitable Domination victory was triggered.

First though, Saladin was eliminated in the deep south:

The Arabian leader had played well in this game, and probably deserved to finish in third place behind Justinian and Cathy. However, his Islamic religion had made him a pariah by the end of the game, and it was not to be. This was one game where it seemed that only the Christian leaders were destined to remain standing at the conclusion. Now Louis slotted into the second place spot, which probably surprised even the French leader. This was one game with a very, very large gap between first and second place.

The last remaining piece of the puzzle was whether Roosevelt would manage to survive to reach the Wildcard game. There was absolutely no chance of turning back the Byzantine armies, which were completely terrifying at this point with tanks and even mechs running around all over the place. Here's a picture of the power bar graphs, which were as dominant as I've ever seen in Civ4. The only hope for the American leader was that Justinian would reach 62% land area and trigger Domination before his entire empire could be swallowed up. I did not think this would be possible, but Justinian was going out his conquest in a profoundly weird fashion, attacking the northern coastal cities before the southern ones that controlled more tiles. By Turn 290, Roosevelt had only the city of New York still standing, the home of Chichen Itza and the location that had bedeviled Cathy earlier in the game. The victory percentage was sitting at 61%, and we had a true nailbiter on our hands here. It was going to take one turn to move all of Justinian's tanks into position, making Turn 291 the critical turn. It came and... the Domination percentage stayed at 61%! That meant that Roosevelt, and this game, were history:

Roosevelt was eliminated on Turn 292, the same turn that Justinian won by Domination. What an incredible finish! I don't believe that we've ever had an elimination on the same turn as a game-ending victory before. Julius Caesar took out Qin a single turn before winning in Game Seven last year, and I think that was our previous closest ending. To get an idea of how close this was, Justinian leaped up from 61% to 66% land area on the turn that victory was achieved. Granted that was because all of the American culture had now disappeared from the map, but it was still a near-run thing. Roosevelt had played a pretty terrible game and there was little interest in seeing him stick around for the Wildcard match. This felt like a deserving conclusion to this game.

This proved to be one of the more interesting AI Survivor matches in a while. We've rarely seen a game where one leader wielded religious control in such an impressive fashion, with Justinian skillfully manipulating the use of the Apostolic Palace to destroy his enemies. Louis came along for the ride, and somehow Montezuma ended up getting carried as part of the Christian coalition as well. To use terminology from League of Legends, this felt like a game where the top laner dies five times in the first fifteen minutes, then gets carried to a victory when the bottom lane gets ridiculously fed and goes on to crush every teamfight. Regardless, we were going to have the pleasure of getting to see Monty again in the Wildcard game, which had the viewers rubbing their hands in anticipation. As for Justinian, he had the Season One magic working again in this game. We'll see if he can make it back to the Championship in his next match.