Civ4 AI Survivor Season 4: Game Five Writeup

Unlike the past two games which had heavy favorites drawn from the two pools of seeded leaders, this game appeared to be much more wide open. The Pool 1 leader for Game Five was Kublai Khan, who reached the championship game twice in Seasons Two and Three but didn't appear to be as strong as some of the true powerhouses in this competition. He was joined in this game by Zara Yacob as the other seeded leader, someone who did well in Season One but struggled in the following two seasons of AI Survivor. The other leaders drawn into this game were a collection of mostly aggressive fellows. We had Alexander and Genghis Khan Temujin, the two of them starting next to one another as neighbors, both of them keen to start cracking some skulls. The Mongol vs Mongol grudge match in this game looked like it would be fun. Tokugawa also made an appearance as the isolationist "I hate everyone else" AI leader personality that rarely seems to achieve much. The one individual who looked out of place in this game was Bismarck, sporting Expansive and Industrious traits that no one else shared. None of the AI leaders in this game seemed to have particularly good economic traits, and in contrast to Game Four, no one started with Mysticism tech and had a particularly strong religious bent. Four of the six leaders in this game were packing the Aggressive trait, meaning free promotions all around for everyone's melee units.

We expected to see Zara found one of the two early religions given his research preferences, and that was indeed what took place when he established Christianity on Turn 20. The open question was who would get the other religion, and a race developed between Kublai Khan and a surprising Bismarck in that regard. Kublai ended up winning this competition by a single turn, and Buddhism popped up in his third city in a nice location towards the middle of the map. This meant that the northern civs would be locked out of the early religions, and the south would see a split between Christianity in Ethiopia and Buddhism in Mongolia. The Monotheism religion would turn out to be Judaism in this game, but it was also founded by Kublai Khan and buried as a minority faith. We would see only those first two religions for a long time.

The early settling patterns were a bit different in this game than in some of the other AI Survivor matches. A couple of the leaders in this game did the usual circular expansion thing, such as Kublai and Alexander and Bismarck. However, other leaders must have been chasing after some of the resource clusters on the map and placed their cities in a strange fashion. Tokugawa went straight west with all of his initial cities, ignoring the land to the north and south of his capital. His second city of Osaka had a gorgeous bunch of resources, with triple food resources and a grassland gems, only for Toku to ignore Mining tech for dozens of turns on end. Sigh. Genghis Khan Temujin sent most of his settlers straight to the south, into the middle of the map, and his borders quickly became entangled with Tokugawa's cities there. Neither of them had researched Mysticism tech (a foolish decision also shared by Alexander) and so we ended up with a series of overlapping cities where none of them had the full two rings of tiles to work. Very unusual to say the least.

Zara was one of the early score leaders thanks to founding Christianity and getting the score points from the free Creative border expansions. For whatever reason he decided to go on a world wonder spree, building the Great Wall and then the Pyramids during the early stages of this game. What he wasn't doing was training settlers, and Ethiopia sat on three cities for far too long while other leaders ate up more and more of the limited space on the map. Genghis Khan had the opposite problem, racing out to seven cities so quickly that he crashed his economy in the worst way. The poor guy was all the way down to 20% research, 5 beakers/turn at one point, and unlike a human player the AI wasn't smart enough to know how to tech on a low science percentage. The northern Mongols would lag behind the other civs in tech throughout this game, something not helped by Temujin's insistence on always researching military techs before economic ones.

There were a couple of significant wonder builds during these peaceful early turns. Bismarck constructed Stonehenge and that seemed to help him out a lot against the Creative civs in the south. Kublai Khan used the Oracle to grab Metal Casting, which wasn't as useful for him since he lacked gold/silver/gems resources. He would have done better to grab Monarchy tech and Hereditary Rule to ameliorate his unhappiness issues. The one thing that Kublai had for happiness was his religion, and that was spreading far and wide along the huge river system in the middle of the continent. First Tokugawa converted to Buddhism, then later on Genghis Khan and Alexander joined him in a four-way Buddhist bloc. This did not bode well for Zara and Bismarck long term, given their high peace weight combined with Zara practicing a different religion.

Not surprisingly, the first war of the game was generated out of the muddled mess of borders in the central part of the map. Both Japan and northern Mongolia still lacked Mysticism tech for monuments as late as Turn 84, and their cities overlapped one another in the worst way. Temujin decided that he wouldn't stand for that and invaded his eastern neighbor. This war initially went well, with the northern Mongols autorazing a new size 1 Japanese city on the eastern coast and eventually capturing Izumo at the furthest edge of the Japanese empire. However, Tokugawa was able to strike back and capture Tiflis, the Mongol city in yellow at the bottom of the screenshot above, and that induced Genghis Khan to sign a peace treaty that returned Izumo. The net result was a lost city in exchange for an autorazed size 1 colony, not a good deal for the northern Mongols. Both Temujin and Tokugawa would remain two of the weaker leaders in the game for the time being.

Elsewhere Alexander had started his own war with Zara Yacob, not caring about the fact that they both practiced Christianity. (Alex would quickly flip into Buddhism as mentioned earlier, thanks to Kublai flooding his territory with Organized Religion missionaries.) Any hope that Zara could use his religion to make friends in this world was being dashed. On that same note, Bismarck was in the process of making a terrible mistake:

He founded Confucianism via Code of Laws tech and swapped over to the religion on the following turn. This was a suicidal decision given that all of the low peace weight civs were practicing Buddhism by this point, while the two high peace weight civs were running Christianity and now Confucianism. The diplomatic politics from this point essentially wrote themselves, with the two "good" leaders isolated from one another and team "evil" singing in four part harmony. Bismarck even decided to make his diplomatic position that much worse by randomly declaring war on Alexander after sending a stack of swords all the way across the map. He captured Sparta but naturally had no way to hold onto the city, achieving nothing for his troubles beyond poisoning the well diplomatically with Greece. Bismarck was doing everything possible to sow the seeds of his own destruction.

Most of the picking contest (myself included) thought that Bismarck's general incompetence would see him as the first to die. Instead, it was Zara's early religion that wound up being the greater poison pill in this game. Rather than allowing Zara to make some friends and survive a bit longer, his Christianity was uniting all of the warmongering leaders against him. Kublai Khan joined Alexander's long-running war on Turn 117, and it wasn't long before the northern Mongols piled on as well:

Zara thus found himself in a 3 vs 1 situation that he couldn't possibly win. Although his cities had strong cultural defenses, Alexander had researched an early Construction tech and possessed catapults to reduce those defenses to zero. It wasn't fast but it was effective. The Buddhist alliance methodically worked to strangle their Ethiopian opposition, sieging down one city after another while picking apart Zara in piecemeal fashion. Alexander was the biggest beneficiary of this conflict, as his catapults gave him the edge when it came to the actual capturing of cities. Kublai Khan had ignored Construction tech for unknown reasons, and therefore even though he had the largest army on the Power graphs, he wasn't doing very well at taking territory from Zara. Wave after wave of southern Mongol soldiers threw themselves against cities with 60% cultural defenses and were destroyed. While Kublai and Temujin each picked up a city for their troubles, Alexander was getting more of them.

This struggle came to a climax outside the Ethiopian capital of Aksum. This was a supremely valuable city to control, with six different wonders inside including the Pyramids and the Mausoleum. Zara had also built the Apostolic Palace to near-completion, 360/360 production finished, only for the wonder not to finish each turn because he whipped out a defender instead. The Apostolic Palace never did finish here as the Zara AI programming desperately tried to get out more units for defense. (Bismarck would later end up constructing the Apostolic Palace attuned to Confucianism as a religion, and it played no role in this game.) Zara whipped Aksum for a military unit every single turn until it had fallen all the way to size 1. The siege of the city lasted for over a dozen turns, with some truly heroic fighting by the Ethiopian defenders. It wasn't enough though, not with three different nations all converging on this single target. In the end it was Alexander who scored the huge prize of taking Aksum, a victory that propelled him up to the top of the leaderboard alongside Kublai Khan. It was almost anticlimactic when Kublai finished off the last city a few turns later:

Farewell to Zara, who was dealt a tough hand in this game. His only realistic shot for survival was making some friends via religious diplomacy, but unfortunately he drew a bunch of leaders into this game who didn't care about religion very much. Zara did convert Alexander to his faith only to see the Greeks invade a few turns later regardless. Once the rest of the world was practicing Buddhism to his Christianity, he basically had no shot and ended up being the first one off the board. As I said, it was a tough draw to be selected for this match.

There was now a huge target on Bismarck's back as the one Confucian leader in this otherwise Buddhist world. Tokugawa had fought an inconclusive war with the Germans while Zara's lands were being partitioned, one that ended up seeing no cities change hands. Unlike the real Bismarck's mastery of realpolitik, AI Bismarck seemed determined to do everything possible to engineer his own demise. He declared war on Kublai Khan on Turn 166, invading his stronger and larger western neighbor from a position of diplomatic isolation. (Real Bismarck must have been spinning in his grave.) It didn't take long for the subsequent dogpile to form: Genghis Khan entered the war on Turn 178, followed by Tokugawa on Turn 182 and Alexander on Turn 183. Germany found itself in a 4 vs 1 situation even worse than what Zara had been up against earlier. Whoops.

The only question now was who would come away with the best spoils from the impending destruction of Germany. Kublai made the initial gain by taking Munich, the border city where the Confucian shrine was located. Tokugawa would end up claiming the two northern cities of Essen and Hamburg, which were the most logical additions to his territory. The big prize was once again the capital city though, with Berlin holding the Apostolic Palace along with the Great Lighthouse and the Colossus. The exact same pattern from the Ethiopian war played out again, with Alexander claiming the enemy capital city along with its treasure trove of wonders. This was particularly handy for Alex because he had about half a dozen coastal cities and reaped major benefits from the Great Lighthouse + Colossus combo. As far as Bismarck went, he was finished off with a pair of random city captures from Genghis Khan, including the kill credit going to Temujin:

Goodbye Bismarck, your streak of AI ineptitude continues unbroken. Four seasons of AI Survivor, four opening round eliminations, zero kills achieved. The biggest winner from the removal of the high peace weight civs looked to be Alexander, as his capture of several Ethiopian cities plus the two monster capitals had risen his standing to first place. Kublai was running neck-and-neck with the Greek leader at the top of the group, although it was fair to say that Kublai had not done as well from these two wars as we expected. If he had researched Construction tech sooner, he likely would have picked up some of the spoils that had gone to Alexander and remained atop the scoreboard. Tokugawa hadn't picked up quite as much territory either, but still remained in the game as a significant player. The runt of the group was the northern Mongols at this point, largely due to the technological backwardness of Temujin. His captured territory wasn't very useful, split up in bits and pieces across the continent. There was no way that Genghis Khan would be able to defend any of that if it came to another major war.

We had a few decades of peace following the end of the German war. The biggest shift diplomatically was Alexander dropping out of Buddhism in favor of Christianity. He did this because he had taken over Zara's Holy City in the earlier war, and the AI prefers to run a religion where they hold the Holy City if possible. This posed a serious danger for Alexander, as the other three civs continued to practice Buddhism and he could potentially see himself as the next target of a 3 vs 1 alliance. Alexander appeared to be inviting that very outcome when he declared war against Kublai Khan on Turn 210:

This was a huge deal, the top two leaders going after one another in a bid for the gamewide victory. Fortunately for Alexander, he had timed his invasion almost perfect. Note his research on the interface: one turn away from finishing Rifling tech. Alexander had beelined there before anything else in the Renaissance era, instead of avoiding Rifling as the AIs so often do. He didn't even have Education or Nationalism techs yet. Instead, the Greeks zeroed in on the key military tech of the era and picked it up before Kublai Khan could get there. Thus even though the southern Mongols had an overall tech lead, Alexander was able to hit them during the narrow window where he could use rifles against medieval units. This proved to be a smashing success and Alexander captured four different border cities over the next half dozen turns. Kublai intelligently responded by going after Rifling tech himself and finished it by Turn 225, but those two dozen turns were enough to be decisive. Alex was clearly winning the war, even if his conquests were mostly crushed by Mongol territory and currently useless to him.

There were now two different ways that this game could play out. In one scenario, Kublai Khan recruited the other two Buddhist civs into his war and Alexander faced a new three-way alliance. This would presumably lead to the collapse of Greece and Kublai most likely rallying to win the game. In the other scenario, Temujin and Tokugawa failed to help the southern Mongols and stood by while Kublai was carved up and destroyed. Or I guess we could see something even crazier come out of Genghis Khan...

Rather than help out the southern Mongols, Temujin decided to invade Tokugawa instead. This was a fateful decision that would have serious longterm consequences. It meant that Kublai was thrown to the wolves and would have to mount his own defense against Alexander, a proposition that looked dicey at best given the growing score lead of the Greeks. As for the northern Mongols and the Japanese, this locked the two of them into a death struggle where Tokugawa held all of the advantages. While these two civs were equal in tech for the moment, they were only at parity because Temujin had ignored everything economic in nature to make a direct beeline for grenadiers and cannons at Steel tech. The northern Mongols were nowhere close to Rifling and lacked the teching power to get there anytime soon. Japan on the other hand was researching along at a good clip and would soon unlock rifles and cavs. It wasn't clear how Temujin planned to defend his cities once that moment arrived.

These were both ferocious wars involving large numbers of units. It could be difficult to follow the action at times, not least because Alexander was conducting his offensives deep within the Mongol cultural borders. The Greeks used their Open Borders with Temujin and (yes) Tokugawa to maneuver around the edges of Kublai's territory, hitting southern Mongol border cities on all sides rather than strictly along the Greek border. The whole outer edge of Kublai's territory fell at different points in time, but he stubbornly held onto the Mongol cities in his core with their massive 80% culture borders. This made it hard for Alexander to advance and it also meant that his conquered cities were essentially useless since they controlled no tiles. Kublai also kept counterattacking and taking back his cities when Alex's armies moved elsewhere. This wasn't an equilibrium that could last forever because Kublai's teching had stalled out at 500 beakers/turn while Alex's untouched cities were continuing to grow in beaker output, but for the moment Kublai was holding his own against a stronger opponent.

The same could not be said for Genghis Khan against Tokugawa. While the northern Mongols did have some initial success against the Japanese in the center of the map, seizing control over two different cities there, the Power bar graphs indicated that Tokugawa was much stronger militarily. It wasn't long before the Japanese picked up Rifling tech and unlocked rifles and cavs, units that the northern Mongols were unable to counter. It turned out that the main Japanese army was down at the bottom of the map conquering the two ex-German cities in the region. Once they fell and Tokugawa shifted his doom stack of 80+ units up to the north, the Mongol core began to collapse. First the long-contested cities in the center of the map were taken, then the Japanese pushed into the deep northern tundra. In a surprisingly short period of time, it was all over with Tokugawa triumphant:

This was another deserved outcome, as Temujin had invaded Tokugawa on two separate occasions. Like Montezuma, it appears that the great khan is simply too aggressive for his own good in these AI Survivor matches. The destruction of the northern Mongols was a huge boon to Tokugawa, and it upset the previous balance of this game. The first two civs to be eliminated had both been partitioned, with their lands split up between multiple different invaders. That had not happened here, with every single captured city snowballing the Japanese empire to a greater size. Once all of those cities came out of resistance and expanded borders, it was clear that Tokugawa had become the runaway AI leader. He had already taken over the lead in military strength, and he was able to build infrastructure and tech in peace while the other two civs continued to fight a destructive war. Increasingly it looked as though Tokugawa had his pick of what victory condition he wanted to achieve.

The northern war had run its course in fairly short fashion while the southern war continued to rage onwards. Again and again it looked like Kublai was finished, only for him to rally his forces anew and recapture one of his lost cities, thereby pushing out the huge Mongol cultural borders once more. This war had started on Turn 210 and it was still very much ongoing a hundred turns later on Turn 310. Both sides reached the next generation of military tech at Assembly Line and deployed infantry + machine guns with no significant change in the combat. But eventually Alex managed to reach Industrialism and unlock tanks, and that unit finally seemed to break the endless stalemate. This was one unit that Kublai wasn't able to counter, and it seemed that he was finally doomed.

And then Tokugawa decided that Alex's time was up:

The Japanese invaded Greece on Turn 334, announcing the beginning of the war with a full-on nuclear exchange. This was the nightmare scenario for Alexander, who lacked Fission tech and had no nuclear weapons of his own, much less the SDI to shoot them down. He was utterly unprotected against this attack and it showed. Even leaving aside the nuclear weapons, Tokugawa was nearing the end of the tech tree and had unlocked modern armor, mechs, and mobile artillery. The Japanese captured four Greek cities on the first turn of the war and the rout was on. The huge empire that Alexander had developed throughout the game melted apart like butter under the noonday sun. We wondered whether he would survive ten turns until a peace treaty could theoretically be signed, not that one was likely to be forthcoming. There was actually one moment here where Tokugawa built the United Nations and he liberated enough captured Mongol cities back to Kublai Khan that a Diplomatic victory was theoretically possible. Tokugawa winning via diplomacy would be absolutely amazing and it was in play here.

But then Alexander's population dropped below Kublai's and that window quickly closed. Oh well. Tokugawa never held a Diplomatic victory vote in the United Nations anyway so it was probably always just a pipe dream. This meant that there would be no reprieve for Alexander and the battle raced on to its inexorable conclusion. The whole war took a mere 14 turns and Alexander was eliminated on Turn 348:

It was incredible how quickly the massive Greek empire disappeared from the map. This is the reason why we ban nuclear weapons in our Multiplayer games; if one side has them and the other doesn't, it's impossible to mount any kind of defense. (Accurate to real life, true, but not the best situation for competitive Multiplayer.) Two nukes kill every defender in a city and then any unit can walk into the unguarded city center tile. Tokugawa used a combination of nuclear weapons and conventional units to finish off Alexander in record time. The Greek leader had deserved a better fate given what a fantastic game he had played. His one mistake was taking far too long to finish off Kublai, and that allowed Tokugawa enough time to absorb a weaker neighbor, tech ahead, and then go for the killing blow.

Our only remaining question was whether Tokugawa would win via Spaceship or Domination. He was about 3% short of the Domination requirement when he cities popped their initial borders, but it seemed clear that when his cities reached the third ring at 100 culture he would pull in enough tiles to put him over the top. Sure enough, even as the Japanese spaceship was en route to Alpha Centauri, a couple cities expanded their tiles and it was enough to trigger the victory:

Tokugawa was actually sitting at 61.96% out of the needed 62% on the previous turn, and I feel bad for anyone who lost points in the prediction contest as a result of that one extra turn. It was an impressive come-from-behind victory for Tokugawa, someone who had been one of the weaker civs coming out of the landgrab phase and largely took advantage of mistakes from the other leaders to reach his position of dominance. Kublai Khan had been in position to snowball this game in his favor and largely failed to do so because he didn't capture enough territory in the partition of Ethiopia and Germany. Then Alexander was in position to run away with the game only to be foiled by the determined resistance of Kublai. This provided the space that Tokugawa needed to steamroll over Genghis Khan and reach runaway status, cementing it with his lategame beatdown of Alex. This was a very different sequence from Julius Caesar's wire-to-wire dominance in Game Three, but ended up achieving an equally powerful finishing position.

While I don't think that Tokugawa is a particularly good AI leader, he's reached the playoffs twice now by taking advantage of weak fields of opponents. If he gets drawn into a group of lesser AIs, he's competent enough to be dangerous. We'll see how he handles the stiffer competition in the upcoming playoff round.