I recently wrote about how the AI in Civ 6 seems to be worse at its own game than previous Civ games. I want to give a shoutout to the youtuber Sulla whose “AI survivor” series put this into sharp contrast for me. Sulla sets up games of Civilization 4 that pit the AIs entirely against each other, with no player involvement. He then looks to see how it all turns out.

In Civilization 4, the AIs will usually manage to conquer each other. The games start with 8 AIs and it’s never been the case that they all survive to reach the end of the game. On the other hand in Civ 6 I rarely see even a single AI get eliminated unless I’m doing the eliminating. It just goes to show how passive the Civ 6 AIs are, and how utterly incapable they are at using 1upt and the rules of their own game.

Just something to think about.

Playing Civ 6 made me nostalgic for Civ 4, so I made it my project to get better at it.  I’ve been watching videos from Sullla’s channel (a big Civ lp-er) and have learned a lot of good stuff that helped me in Civ 4

Now to start with this victory wasn’t exactly easy.  I took the most broken, OP leader in Civ 4 (Huana Capac) and used a map-type that the AI does really poorly in (highlands with dense peaks, AI pathfinding screws up).  Even then I did a tiny bit of save-scumming at the beginning to fight off the barbarians.  But once things were going, I found that a Civ 4 game can be really easy… when it acts like a Civ 6 game.  Let me explain:

The reason Highlands map is so easy is as I said the AI’s pathfinding screws up.  I never got war declared on me during my Emperor level game, my only neighbor was Charlemagne who loved me because I adopted his religion, and my other close neighbors fought inconclusive wars amongst each other with no territory changing hands.  This let me sit back and tech away, *and that’s also how I won my Civ 6 deity game*.  It’s made me definitely appreciate that one of the big things holding back Civ 6 difficulty is the AIs’ inability to conquer each other and snowball out of control.  In a normal Civ 4 game one or more AIs will declare war, conquer their neighbor, and suddenly roll right up to the player’s boarders with the world’s largest army in tow.  A successful conqueror loses relatively few units to gain a lot of territory, and unsuccessful one throws away all their production producing units.  This helps AIs snowball when they focus on conquest. I don’t know exactly why Civ 6 AI is unable to conquer each other (OK I do, it’s 1upt) but this failure is a large part of the reason why I think they aren’t able to challenge a player once you escape the early game and are in the midgame.  No single AI will be so far ahead of everyone as to be unstoppable, everyone is usually around the same size.

So that’s a bunch of random thoughts, but it’s what I thought of when playing Civ 4.

I don’t know if I’ve blogged about Civilization 6 before.  The game has received its final DLCs and the devs have all but left to work on Civ 7, so I guess being 5 years late is the perfect time to talk about it.  Warning, this is a long post.  Also warning, I do enjoy Civ 6 and pretty much every Civ game I’ve ever played, but I will be very critical in this post.

To step back a moment, I’ve played every Civilization game since 3.  Most Civ games have a difficulty scale with funny little names, but basically there are 8ish levels of difficulty, and the AI gets progressively more bonuses as difficulty increases.  In 3, I could barely win on difficulty 3 of 8.  In Civ 4, I could reliably win on difficulty 5 of 8, and sometimes 6 of 8 (Emperor) with the right setups.  In Civ 5, I could win on 6 of 8 reliably, and once managed 7 or 8 using a broken setup and a lot of savescumming.  

Difficulty level 8 of 8 is always called Deity, and it is always an exceptional challenge with the AI receiving ludicrous bonuses to every single statistic.  I have never beaten any Civ game on Deity.  Until Civ 6.

Civilization 6 was the first game I beat on Deity and the crazy thing is I don’t actually think I’m better at Civ 6 than I was at Civ 4 or 5.  I know I’m bad at Civ 3, but that’s because I hate the trading mechanics.  But with Civ 6, I genuinely think it’s just an easier game than its predecessors in an interesting and perhaps bad way.

To start off, let’s discuss how the Civ games make higher level AIs difficult.  They don’t particularly add any new mechanics or strategies, they just give the AIs big multiples to everything they do.  At high levels, an AI city will grow 50% faster, train units 50% faster, build buildings 50% faster, and they start with free technologies.  At the highest difficulty of Deity, the AI also gets to start with 2 settlers to the player’s 1.  That means that on Deity, the AI will start with twice as many cities as the player does, and each city will be 50% more productive.  

That’s a big hole to dig yourself out of, but the player has much better knowledge of the game mechanics and so a very good player can still win, even on Deity.  

The thing is that the AIs understood the game mechanics in 4 and 5 a hell of a lot better than they do in 6.  Some would say 6 is more complex, but I don’t buy that, I think in many ways it has (thankfully) been made simpler and more streamlined for easier access.  But I do think the Civ 6 AI understands its own game a lot worse than 4 and 5.  

It comes down to “one unit per tile” or 1upt as it’s known in Civ circles.  In Civ 4, you could stack as many buildings and as many units on a tile as you wanted.  Want your city to have a forge, a market, a theatre, and be garrisoned by 10 archer units?  Go ahead.  Civ 5 changed this in that only 1 archer unit can ever fit on any tile, but they didn’t update the AIs to make them good at this new system.  There’s a complex juggling act that is needed to make all your units be effective when you can’t stack them all on a tile.  And the AI is not good at this juggling act.

In Civ 4 the AI wasn’t great but it was at least smart enough to gather a dozen units and march towards the nearest city.  If you only had a single archer in that city, well even Alexander the Great can’t win against those odds.  But in Civ 5, the AIs will gather a dozen units, and they will all get in each other’s way as they fail to march against an enemy city.  A single archer in Civ 5 can indeed pick off their enemies one by one, defeating a dozen units without taking a scratch.

So with 1upt, wars in Civilization became heavily player-favored, as no amount of enemy numerical advantage could make up for their incompetence.  However the Civ 5 AIs still had ungodly bonuses that could let them tech up and win the game through other means.

Civ 6 then decided to “unstack the cities,” doing to cities what 1upt had done to military units.  Now you could no longer have a forge, a market, and a theatre all in one place.  They had to be spread across the map of your city.  To make this mechanic fun, they added “adjacency bonuses” so that buildings work a lot better when they’re near things that help them.  If a market is near a river, then it can trade with far away places easier and it makes more gold.  If a theatre is near a world wonder, then it’s in a more beautiful part of town and produces more culture.  The player is encouraged to use these adjacency bonuses to get the most out of their buildings.  The AI… cannot do this to save its life.

Just like 1upt led to the AI being terrible at war, districts led to the AI being terrible at peace.  They have no ability to manage districts or even look for the best spots to place them.  You’ll often conquer an AI city and see districts placed in just such a way that they have zero adjacency bonus, which is hard to do if you know even just look at the tooltips.  They also seem to hyperfocus on research to the expense of all else, which doesn’t really help them.

But on deity the AI is still hard.  In fact, Deity AIs in Civ 6 are the hardest they’ve ever been, getting to start the game with three free settlers and a good sized army while the player starts with a single settler and a warrior.

But this gives a game against Deity AIs a sort of strange difficulty curve.  On turn 1 every single AI is more than three times as strong as you because they start with 3 settlers and their cities get free bonuses.  But as the turns go on the player makes more and more good choices while the AIs make poor ones.  Eventually the player pulls ahead of the AIs, and then starts to “snowball” from there.  Snowballing in strategy games is when the strongest ones in the game get even stronger over time relative to their peers.  Players always snowball better than the AI and so once a player is stronger than the AI, they’ll never ever be weaker again.  

So in a game against Civ 6 deity AIs, the first few turns are the hardest by far, and you can die within the first 10 turns easily.  But if you just make it to turn 50, you’re golden, untouchable even.  The AI isn’t skilled at getting any kind of victory, so even with their huge bonuses you can snowball out ahead of them and get whatever victory you want at your leisure.  This difficulty curve existed in every Civ game, but it is at its harshest in Civ 6 because the AIs have never been worse at playing their own game.

So while I have gotten my first Deity-level victory in Civ 6, I don’t actually feel like I’m all that good at it.  I feel like I’m playing chess against a 5-year-old only they’ve replaced all their pawns with queens.  I feel like this is definitely something that needs to be improved upon in Civ 7.  “Better AI!” isn’t exactly a hype-worthy back-of-the-box quote, but these are primarily single player games and I feel the single player experience is paramount.  I think I’d enjoy my time much more if I felt that my victories were from being out-maneuvered and outplanned, rather than because my opponents got free stuff at the start.  And I think it would be more fun if I could be ahead all game and then a smart AI could sneak up and overtake me in the lategame.  As it stands, once we’re out of the classical age, I’m golden.

I know no one at Firaxis games reads my blog, but if someone could tell John Civilization to fix his AI, that’d be great.