Civ4 AI Survivor: Introduction

As I write this paragraph, here in the United States the sports calendar is about to roll over to the NCAA Basketball Tournament, better known as "March Madness". This is the annual basketball tournament for American colleges and universities, which effectively functions as a minor league system for the pros. The tournament pulls in 68 different teams from across the nation, played out over three weeks of single elimination competition until only a single winner remains. The tourney began as a true amateur competition back in the early 20th century, but today it exists as a massive moneymaking enterprize, with billions of dollars invested each year by corporate advertisers eager to tap into the live television audience. The tournament is also one of the biggest gambling events in the US, with almost everyone filling out brackets and attempting to predict which teams will win their games and advance to the next round. Although the incredible importance placed on the outcome of these games can be a bit baffling (especially to non-Americans who correctly wonder why universities function as professional sporting leagues), it's impossible to deny the drama that gets produced every year. With 67 basketball games to be played, there will always be some amazing finishes and unlikely upsets, if only by the law of averages. I'll readily admit that watching 48 games in four days during the first weekend of the tournament is one of my favorite events of the year.

With tournament fever on the brain, I thought it would be fun to run a similar competition for Civilization 4, only pitting the AI leaders against one another in a reality TV battle to see who could survive until the end. Which AI personalities perform the best, the peaceful ones or the militaristic ones? The religious fanatics or the builders obsessed with wonders? And of course, there's always a certain amount of randomness in every game as well, from the map and from who neighbors whom, just like finding an immunity idol can suddenly swing the results of a tribal council meeting. It's time for us to play Civ4 AI Survivor!

I will readily admit that this is not an original idea. I was inspired by stumbling across the AI Tournament taking place at CivFanatics, which I've linked here and I encourage anyone reading to go check out. However, there are two key differences that I plan to use for my own setup here. First of all, the CivFanatics group plays their AI simulations with the default setting that includes vassal states. This results in a crazy patchwork quilt of AIs vassaling to one another and breaking free, in a never-ending soap opera of backstabs and betrayals. The mechanic by which one AI vassals to another AI is heavily based on randomness, and I saw entire games swinging on how those dice rolls went down. Furthermore, the vassalage mechanic resulted in AIs surviving indefinitely in very weak positions, almost never dying, rather than being wiped from the board. I don't find it very interesting to read about games where AIs vassaling to one another were 75% of the action, so we'll be turning them off for this game.

The other major change for our competition compared to the CivFanatics one is that we'll be turning off Tech Trading for our games. It's understandable why the CivFanatics group kept tech trading in place, since it's the default option and most of the Single Player strategies in Civ4 are heavily based around trading techs. However, when tech trading is left on, the AIs tend to stay bunched together with no one ever getting too far ahead or falling too far behind. With everyone fielding the same units, it becomes difficult for the AIs to attack one another successfully, and generally makes for less interesting games. But when tech trading gets switched off, all of the AIs have to sink or swim based on their own research efforts. This spreads them out much more widely on the tech tree, and once the laggards fall a full generation behind in military tech, they tend to get swallowed up by their more advanced rivals. In other words... pretty much exactly how we play Multiplayer Civ4. Turning off tech trading makes for more exciting and action-filled games, which is why we'll be going with that option. (This is also a buff to peaceful civs and a nerf to the aggressive ones compared to the CivFanatics setup, for the curious. But if Montezuma can't be bothered to research his own techs, he shouldn't be able to trade for them for pennies on the dollar, right?)

Here are our planned game settings:

* Pangaea map script
* Standard map size, Normal game speed
* Standard climate, sea level, etc.
* No tech trading, no vassal states, no events
* Aggressive AI
* All AIs set to Deity

We're looking to go for very standard settings here, nothing unusual. Pangaea is one of the default scripts, and one of the best ways to make sure that all of the AIs start next to one another. The AI is infamous for being bad at water maps, so we'll put them all on one big continent and make sure there are no overseas islands. (Sorry Portugal and the Netherlands!) Tech trading, vassal states, and events will all be turned off, but we'll leave barbarians on. The random locations where barb cities pop up make for another interesting element that drives conflict between AIs, while avoiding some of the nonsense that comes from events. I'll check the Aggressive AI setting, which is supposed to make them more likely to declare war. (Note: I can't remember if this affects their interactions with one another, or only with the player. It won't hurt in either case.) And finally, of course we're setting all the AIs to Deity difficulty. Quite aside from sounding cool, this speeds up the performance of the AIs so that everything happens faster. It doesn't mean that they're any smarter - they most certainly aren't - but it does mean that we'll see cities go down faster, more units produced, more wars fought, and earlier victory dates achieved. The game continues until one of the AI civs wins, although the cheezy Apostolic Palace victory won't be an option due to the presence of the player's observer civ tucked away in the ice. That's fine with me, the AP victory shouldn't exist anyway.

Here's a look at our bracket structure:

Civ4 has 52 leaders, which makes dividing them into a bracket a bit of an odd task. The best solution seems to be setting up eight opening round games with 6 AIs in each match (6 x 8 = 48), with half of those games having 7 AIs instead of 6 AIs. That comes out to (6 x 4) + (7 x 4) = 24 + 28 = 52 AI civs. In each game, the winning leader will advance to the next round, along with the second place leader as determined by score at game's end. Score is a reasonable proxy for overall development in Civ4, and we're used to measuring performance that way from our Multiplayer events. That gets us to 16 leaders for the playoff round. In addition, we'll pick two "wildcards" from the opening round to add to the pool, leaders who threw out strong or memorable or insane performances but fell short of making the top two in their particular games. This leaves us with three playoff games with 6 AIs in each, with the top two leaders qualifying for one final championship round with everything on the line.

Why 6 AIs per game? It seems to work out well for a number of different reasons. For one thing, Civ4 defaults to 6 AI opponents on a Standard size map. Six empires is also a nice balance between having enough factions to be interesting, without being overwhelmed by too many competitors at once. (Master of Orion also defaults to six empires on each map, and that's a game worth imitating.) I also found that having 6-7 AIs on each map would produce a reasonable number of games, whereas going down to 4-5 AIs would force way too many total games, and on the other hand, 8 or more AIs per map would overload my computer in the later stages of the game. I'm serious - just watch how many units the Deity AIs can crank out! Anyway, while it's somewhat arbitrary as a number, I think it will work well enough.

The plan is to run this over the next few weeks coinciding with the NCAA Tournament here in the United States. Feel free to follow along over at the forums at Realms Beyond, and add your predictions of who's going to come out on top in each matchup. From the testing that I did beforehand, these games tend to get very interesting, very fast. This should be fun.

Opening Round

Game One: Brennus, Napoleon, Peter, Ramesses, Suryavarman, Tokugawa

Game Two: Hatshepsut, Justinian, Mansa Musa, Mehmed, Roosevelt, Willem, Zara

Game Three: Alexander, Boudica, Isabella, Joao, Louis, Qin

Game Four: Genghis Khan, Gilgamesh, Huayna Capac, Montezuma, Shaka, Sitting Bull, Suleiman

Game Five: Augustus, Hammurabi, Kublai Khan, Lincoln, Ragnar, Washington

Game Six: Darius, De Gaulle, Elizabeth, Frederick, Julius Caesar, Pacal, Pericles

Game Seven: Catherine, Charlemagne, Gandhi, Saladin, Stalin, Victoria

Game Eight: Asoka, Bismarck, Churchill, Cyrus, Hannibal, Mao Zedong, Wang Kon

Playoff Round

Wildcard Game

Playoff Game One

Playoff Game Two

Playoff Game Three

Final Round

Championship Game