Beginner’s Guide to One City Challenge (OCC)

Having played the One City Challenge a few times now I’ve realized that its one of the most exciting ways to play Civ IV, so I decided to write a short article to get people interested.

For those of you who are unfamiliar with it, the One City Challenge (or OCC for short) limits the human player to only one city. The computer players can (and do) build as many cities as they want. Sound hard? Well maybe… The good news is the limits on two national wonders per city are lifted, as are the limits on wonders that require a certain number of building as prerequisites (except monasteries for some reason).

Starting The Game

To begin a One City Challenge game you need to go to the custom game menu and check the box marked One City Challenge. Note: while the descriptive text says one city at a time, this is misleading, its one city forever. You can’t switch cities even if you capture a nice one from a rival, and cities that culture flip automatically get razed. So be sure you start in a good place, because that’s the one and only city you’re going to get!


Since resources are spread out more on larger maps, they’re naturally harder to play a OCC game on. If you’re feeling brave, go right ahead, but I usually start on a Tiny Pangaea map with 3 Civs. It guarantees you a few good resources on your start.

Victory Conditions:

It will probably be a good idea to change the normal victory conditions. A culture win is impossible for a human player on an OCC game, so I usually uncheck that box (note to Firaxis, might want to change that). Also, I usually uncheck the Time and Diplomatic victories as well, since the AI players can expand, they usually gain more points than the human player with one city can. Update: if you want to play with the Permanent Alliance option on, it allows more variety in an OCC game. Because you are permanently allied with another player, the Cultural victory option becomes available (3 cities with legendary culture) and the Diplomatic and Time victories also become more easily attainable. Its your game, have fun with it.


Choose your Civ wisely, because it makes a big difference in this game! As will be mentioned later, health, wonders and great people are key aspects to an OCC game, so I usually pick a Civ with combinations that will help me out in those areas (expansive, philosophical, industrious.) I usually forgo a financial Civ because cottage spamming isn’t really a viable option for this game, you just don’t have the space.

The Early Game

Probably the most important part of the game for an OCC player is the early game, because it determines how many wonders will be built, and how quickly Great People will start accumulating. But before we move into too many aspects of the early game, I’d like to cover the key game elements to winning the OCC game.

Key Game Elements

There are three key areas an OCC player needs to pay attention to in order to become a significant threat to the AI: health, wonders, and great people.

Health: probably the most important aspect to an OCC game, it determines how large your city can grow. In most OCC games, city size is limited only by health (we’ll get into why happiness isn’t a problem later). So be sure you maximize your chances for a healthy city! This means moving next to fresh water (+2 health) if you can, and away from jungles and towards forests. Also, one health resource is probably more important than two or more happiness resources, so if you have a choice, chose the health resources. Of course any resources are good, since you can always trade them away for gold, and sometimes for health resources, but be careful, the AI is stingy! The only exception to this is Flood Plains, they provide enough food to give you some specialists.

Wonders: another very important tool in the OCC arsenal (I’ve always wanted to say that.) Along with their usual benefits, wonders also work at constantly expanding your cultural borders, thereby giving you more territory, and probably more resources. But their most important role is providing the ever important GPP (Great People Points) that keep you ahead of the AI.

Which leads us to great people, that last key element of an OCC game. I use all forms, but generally I find Great Engineers and Great Prophets to be the most important, especially in the early game. Great Scientists are useful for the Academy they give you, and also for discovering techs, while Great Artists keep your borders expanding constantly, allowing you to take over neighboring resources. Occasionally I get a Great Merchant, but since I play on a small map, they’re not too useful, especially in large numbers. Others, however, find them to be incredibly useful, you can read their strategies in later posts.

Starting Location and Resources

Now that we’ve covered some key elements, lets get back to starting our game. To begin with, check out your starting location. Sometimes I keep my settler stationary and explore with my scout to try and find a better area. In an OCC game, its not really what’s in your city radius as what’s just outside of it. Because your culture expands fairly quickly, you generally get access to resources rather fast. But at some point your borders slow down or the AI builds next to you, which means you should start your city with enough resources 6 to 7 squares away in order to ensure early game access to them. Anything outside of that means you’ll have to wait a bit longer for your culture to catch up. So if you have your choice, move closer to health resources and away from happiness ones.

On a related note, I should mention two other resources that are vitally important to the OCC win: marble and stone. Since they increase wonder production, they’re even worth moving away from a health resource to get. Especially if you can get to within 4 or less squares right away. This will allow you to punch a worker out as quickly as possible, by which time your borders will expand enough to envelop the resource, and you can hook it up and start producing wonders.

To end the resource discussion, remember that unless you start on the coast you’ll never be able to produce workboats to get access to sea-based resources (and the health they provide.) Its very frustrating to see your borders expand to the open ocean, and not be able to do anything about it. So if you notice an abundance of water resources, you may want to start on the coast.

Early Game Tech and Production

Since wonders are an important part of an OCC game, I usually beeline for techs that give me wonders. A nice thing about the game is that you don’t have to worry about building any settlers! So while the AI is building theirs, you can be starting your first wonder. Usually I build a warrior until the my city reaches a size two, then I switch to a worker, and then finish the warrior and start my first wonder.

Religion: I generally don’t bother with starting a religion. Usually I let others spread theirs to me so I can switch depending on who I want to please, plus I don’t want to lose turns building the missionaries that make them worth while. Since unhappiness isn’t really a factor in an OCC game (usually,) their only worth is monastaries and gold from shrines. Its up to you if you want to make this part of your game, I think either way can work. Just remember, you only have one city, so you have to justify everything you build!

Ok, so which Techs to research? I usually start with the worker techs, (animal husbandry, agriculture, the wheel, fishing, mining, masonry) since I really want my worker to get out and start hooking up my resources, especially if there’s marble or stone about. Polytheism is also an important tech, because it allows you to build Stonehenge, one of the cheapest wonders. You should also go for Priesthood, to build the Oracle, and Masonry, which allows you to build the Pyramids. After that, you may want to research a few militaristic techs in order to be able to produce something other than Warriors, because barbarians are going to become a problem about this time.

Now, which wonder do you build first? This is actually a hard question. If you build the Pyramids first, your first GP (Great Person) is going to be an engineer, who can rush your second wonder. If you build Stonehenge, it will be a Great Prophet, who provides a substantial gold and hammer boost. I usually chose Stonehenge because it’s the cheapest, and the Great Prophet is amazing. Turn them into a super specialists right away, they provide a production boost and start your treasury going. Then I usually build the Oracle for the free tech, and then the Parthenon, for the GP boost. I’ll try the Pyramids if nobody has gotten to them yet.

The Rest of the Game

This part is rather vague, since I can’t really cover how every game will go. But I will note a few things for you to watch out for.

First, stay current in your military, and keep building units! You may feel safe seeing six units inside your city, but really you’re not! Trust me, you’ll always need more. I usually keep a line of defense along my borders on hills and in forests to keep barbarians and other civ’s out. Pillaging can kill an OCC city, so don’t let the enemy get too close. Also, you need more units than you think. The AI can arrive quickly with a stack that will demolish your city garrison in a heartbeat. Its better to meet them out in the field by playing a defensive game in the forest and on hills. I usually have my worker (I usually only produce one a game) build roads when they have nothing to do. It allows me to get my units out from my city quickly, and attack and withdraw in the same move if need be.

You don’t need to build every wonder! Ok, that sounds funny, but I’ve come close. But some wonders just won’t do anything at all for you, so use that time to build military units instead, or produce research if you can. Stay away from maintenance wonders and buildings, which means Versailles and a courthouse, there’s no need. You can also forgo ones like Notre Dame, the Spiral Minaret and the Sistine Chapel.

So what wonders are important? Probably one of the most important national wonders is the Globe Theater. It eliminates all unhappiness in the city its built in. And hey, you only have one city! If only there was a building like that for health… Since its very important, its often worth it to make a beeline for Theater if you’re having problems with happiness. It means you can be at war without worrying about war wariness, and you can also grow as large as you like. It also allows you to trade away your happiness resources for health ones if you can (which is why health resources are more important, once you build the Globe Theater you don’t need the happiness ones anymore.) However, be aware that some happiness resources can provide health in connection with some buildings later in the game, so check which ones you’ve traded, and get them back later if you need to.

Other wonders which do a lot of good are the Great Library, The Hanging Gardens and The Parthenon. I generally stay away from wonders which provide small but valuable bonuses across an empire, such as the Statue of Liberty, the Sistine Chapel, the Eiffel Tower, and the Great Lighthouse. It’s a hard choice because you only have one city, so it may not be worth it. But if you have the time, have a good amount of military units etc., you may want to go for it, because the bonuses are good, even though small.

You may face a problem with happiness in the early/mid game stage. It usually comes at the point at which you’ve exhausted your happiness resources, but haven’t yet been able to build the Globe Theater. A solution to this is researching Monarchy and switching to the Hereditary Rule civic. It gives you +1 happiness per military unit in the city, which means anytime you have an unhappiness problem, just build another unit. Since you always need another unit, this is a good thing. A quick way to get this there is to build the Oracle and use the free tech for Monarchy. Since its usually worth the most beakers, this makes sense anyways, plus you get the added bonus of the civic.

Don’t neglect your health techs: they’re very important, so make time for researching them. This means Pottery, (for granaries) Mathematics, (for Aqueducts, and the Hanging Gardens if you can) and Guilds (for Grocers).

Use your Great Artists for Culture Bombs: it may seem like a lost cause, but its not, you’ll notice your borders moving slowly but surely. Sometimes its even fun, because culture flipped cities automatically raze themselves, so its like watching a blast radiating outwards from your capital in slow motion. Coupled with the culture of your wonders, you can get access to resources three or even 4 squares into your neighbors territory.

Bureaucracy: ahh, the most wonderful of civics. Really, its amazing. Head for Civil Service quickly and pick it up. The +50% boost in production and gold is worth staying with it the rest of the game. Another useful civic is Pacifism, giving you a 100% boost in GP points. I also find Mercantilism to be a somewhat useful tech as well, along with Representation, which provides a nice boost to your science levels.

So there you have it, that’s all I can think of right now. If I have any more I’ll add it later. I hope you enjoy your OCC game.

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