Introduction The one city challenge (or OCC) is a variant on the normal game of Civ which can be a lot of fun if you feel up to the challenge. As the name implies you are restricted to one city (N.B. the other civs can build multiple cities as normal - some people have become confused on this point). OCCs tend to be quite quick games due to only having one city to manage, and tend to be the equivalent of a couple of difficulty levels harder than a normal game at the same level. The difficulty is also somewhat dependent on map size - your opponenents with multiple cities will have a far greater advantage on a huge map than a tiny one. Many strategies that would normally work are of course no longer available in an OCC, and some normally very poor strategies can be unusually powerful. Victory Types Not all victory types can be obtained in an OCC, and with only one city you need to plan far ahead to get one of the remaining types: Cultural: This victory is impossible to obtain in an OCC since you can't get three cities (OK, you can win this one with a permanent alliance to another civ with two legendary cities, but that is not a true one city challenge). Domination: Also impossible in an OCC. One city, even at legendary culture on a duel size map, cannnot cover enough land area to meet this victory condition. Conquest: This one is still possible to achieve by raising all enemy cities, but is highly map size dependent. While a definite option on the small sizes, the limited military of an OCC makes this victory impractical on large or huge maps. Space Race: This is the easiest of the victories to get in an OCC, but keeping up with the tech pace, and building a functional spaceship in a single city are not trivial Diplomatic: It's possible to get this victory from either the UN or AP under OCC, but you'll need genuine diplomacy to do so. Voting yourself in i no longer an option. Time: Included for completeness, but not really a victory. In any case, with the low level of population and land area in an OCC you're unlikely to be top of the score table. National Wonders The restriction to two national wonders per city is lifted for the OCC, providing the player with a way of increasing the power of his one city beyond normal levels. While originally there was no limit on national wonders in the OCC, the BtS expansion put a new cap of 5 national wonders in place, making their choice a major strategic element of the OCC. These wonder now act on your entire civ (of one city) so it is vital to choose them wisely. I'll run through their relative strengths and weaknesses: Moai Statues: These can be of use if your one city has a large number (i.e. 10+) water tiles, and this wonder can be put in place extremely early. If you only have a few water tiles, I wouldn't waste one of your precious five slots on this one. Heroic Epic: You can build all military twice as fast, obviously a major advantage. In an OCC though you usually have to avoid warfare, so this might not be the best choice (and getting a high level unit might also be problematic). Still, if you do get dragged into a war, this wonder will be a great help. National Epic: Your one city is defacto your great person farm, and great people are vital in an OCC. This national wonder is a must have. Globe Theatre: This wonder ensures you never need to worry about unhappiness again. You can forget all happiness boosters, war weariness, and you can defy as many resolutions as you like, and your people will stay happy. It also opens up powerful options for drafting units. This wonder is another must for an OCC. National Park: The health counterpart to the Globe Theatre, but this one has a nasty catch in it. If you build this you can forget health boosters - no need to waste time on hospitals, public transport, etc. You might also get some specialists, but forests generally do not survive long enough in the city radius for this to happen in an OCC. The catch is that this wonder removes all access to coal. This means the Ironworks will only give a 50% rather than a 100% boost. It mean a coal plant cannot be built. Certain units cannot be constructed and you'll have to wait for oil to build railroads. You also can't found Aluminium Co. (I had one infuriating OCC where I was trying to win space race, had coal but no aluminium in my borders, and even turned up a great engineer at the right moment - but I still couldn't get aluminium this way). There's strong arguments either way for this wonder. Ironworks: 100% boost to production for everything, and more engineer slots? The power of this one is obvious, though it will be weakened to 50% if you have the national park. Another very good candidate for an OCC. Oxford University: With only one city to do research you need to make the most of it, so again this is a strong candidate for the 100% science boost. The extra scientist slots are mostly irrelevant in an OCC though. Wall Street: In most OCCs you'll be running at 100% science, and even with merchant specialists this won't give that much. In the later stages it'll boost your corporation from 10 to 15gpt, but I'm dubious if this is worth using up a national wonder slot for. OCCs have minimal maintenance costs, and gold is rarely a problem. West Point: All units get +4 experience when built - again a useful boost. If you are going for conquest then this is an obvious candidate; you can't get strength of numbers, so your units need to be highly promoted. Red Cross: All units start with Medic I (wow). This is not a useful wonder in an OCC, and can be ignored. Hermitage: A cultural victory is impossible in an OCC, and thanks to wonders your one city will hit legendary quite fast enough on its own. There's no need to waste a slot on this one. Mount Rushmore: Since the Globe Theatre keeps your population happy whatever, this national wonder is completely redundant in an OCC. Forbidden Palace: Since it cannot be built in a capital, this one cannot be built in an OCC, and wouldn't do anything useful if you could. Traits Another major difference of the OCC is that many of the clasically strong traits are of minimal use, for example... Financial: You'll never have more than 20 tiles to work in an OCC, cottages are not a strong as normal due to the importance of great people, and many tiles won't give 2 commerce to start with anyway. This is actually quite a weak trait for the OCC, and can never give more than 20 commerce per turn Industrious: With wonder spam a major tactic in an OCC, this trait really shines, Philosophical: One way or another, great people power the OCC economy, so this is another excellent trait for the challenge. Charismatic: If you are going to try for the conquest, the lower experience caps will prove useful, and the happiness can help in the early phase of the game. This isn't as strong as normal though. Spiritual: You can still micromanage civics as much as always, and a few early temples are worth having, so this is slightly stronger than normal. Aggressive: Again, good for warfare and will aid in defending yourself to some extent. Not a first rate trait, but worth having. Organized: Civic upkeep is trivial in an OCC, and the cheap buildings aren't that impressive. Not a very strong trait. Creative: Your palace and later wonders will expand your city's borders quite happily. A cheap library will save a few turns, but the colosseum and broadcast tower will probably never get built thanks to the Globe. A weak trait. Expansive: You won't build many workers in an OCC. The couple of health may help a bit if you decide not to build the National Park, but this is still a weak trait. Protective: While normally near the bottom of the barrel, this is actually a decent trait in an OCC. When you need to hold off an aggressive neighbour with minimal units, the bonus promotions of this trait can be a lifesaver. Imperialistic: Wow - a trait which boosts settler production in a game where you can't build any. While stacked great generals as military instructors might make a slight difference if you're going for conquest, in many OCC this trait will be 100% useless. Basic Strategies OK, we've run through the traits and and your targets; now how do you actually get there? The major challenges are going to be keeping up in the tech race, and avoiding getting destroyed by a neighbouring civ (pray you don't get someone like Monty as a neighbour). Starting Position Think carefully before you found in place. This is the only city you'll have, so make the most of it. Be very wary of founding in a non-coastal location, as this will prevent you from building any ships for the entire game. On a continents map you'll have real trouble with conquest if you're not coastal. Stick to rivers for the extra health and the levee, and watch for resources that you can at least get connected to your trade network if not use directly. Religion Initially you actually have an advantage in the religion race- you're not going to be stagnating your city building settlers. You should therefore have little trouble grabbing a religion on all but the highest levels. Your capital is free to build Stonehenge without stunting your empire's growth, giving you a prophet for the shrine. One religious shrine can pay your maintenance for the whole game in an OCC, and can save you numerous diplomatic headaches. Many civs sharing a religion with you can be turned in to your defenders rather than threats, a long as they are not a backstabber. Even if you decide to go conquest, an early shrine is invaluable to help pay unit upkeep. Wonderspam You've built your basic city improvements and some defenders - now what? In an OCC wonder construction is a major part of the game. Pile them in to your ciy, build up great people points from them in addition to your specialists. You can then either merge the resulting great people to further boost your city, or use them to lightbulb tech to help keep pace with the larger civs. This is essentially Obsolete's wonderspam strategy, but its particularly well suited to the OCC. Keeping up in the Tech Race In the early stages when you can laugh at all the other civs with low science rates due to the maintenance cost of all their cities, and build up a lead. Eventually those cities are going to mature though, and no matter what they're going to start out researching your lone city. You have a few options though. You can use your great people to lightbulb tech, and trade it around to help keep pace. (You can probably get the Oracle as well for a slingshot). You could try running spies (or getting a great spy from the great wall) and stealing tech, though this loses effectiveness in the later stages. Later on though, you really need to rely on careful tech trading (an OCC is very difficult if this is switched off). Pick a tech the AI tends to avoid to spend your limited research on, and trade it to everyone for whatever you can get. With Oxford you maybe a slow researcher, but still capable of doing a certain amount yourself. Defense However much you try, odds are you'll end up getting attacked in an OCC, as you'll usually be stone last on the power graph, attracting the aggressive AIs. Get walls and a castle in your city, and keep highly promoted city garrison units there. Have a stack of mounted units to engage the enemy - remember you city will have huge culture, so they'll have to track through a fair amount of your territory to reach your city. Have your worker(s) build junk improvements on the tiles outside your city radius to slow them down with pointless pillaging while you build and draft additional defenders. Unless you're going conquest, all you're trying to do is survive. It's the midgame that's generally hardest. Once rifles and infantry show up, you're generally OK, as you can hold off large stacks with a few of these. Ban nukes if you get the opportunity - a couple on your city will destroy you, whereas those with many cities can soak up the damage. Corporations These really shine in an OCC. The maintenance is at a minimum, you can still spam them to foreign civs to your heart's content, and they provide a way to further boost your lone city. Sushi and Mining Inc are probably your best bet - its hard to go wrong with food and production, and you can usually trade for lots of seafood. Since the AI is poor at figuring out the true value of resources, you can often buy seafood for 3-4gpt, which is well worth doing when you have many foreign corporation branches bringing in loads of gold. Strategic resources on the other hand tend to be expensive, but you can still buy a few for mining Inc, and spam the corporation to anyone that won't trade. You have to get used to buying resources for plain gpt. You won't have many spare resources to trade due to your limmited land area (though in the later stages you can do well by building the "hits" wonders and trading these around). You can even run enviromentalism without corporation costs becoming a problem - good for health if you don't build the national park, and you can force this civic with the UN, opening all civs to your corporations. Warfare The OCC relies on tech brokering, but if you get a chance to bribe another civ to war with a third for tech, its generally a good idea to go for it. If they're fighting each other they won't go after you, and it'll slow their tech pace. Given the choice, side with your neighbour (who may often almost surround you in an OCC - try not to offend them). Space Race Unlike the normal game, it is production rather than research which is normally the problem, especially if you don't have aluminium. You can't build parts in parallel now, so it isn't always a good idea to build a complete ship. The second engine in particular is usually not worth delaying the launch for, and four of the thrusters can alsos be junked if you need to concentrate on the more important casings. Finally, don't forget the AI will often sling everything it has at you when your spaceship is launched - make sure you have the defenders to hold them off till it gets there. In Conclusion One final point - this variant is supposed to be challenging, so don't be surprised if you can only win a difficulty level or two below your normal one. I've yet to beat it above Emperor level. I may add a quick walkthrough of one of my OCC games later if people are interested.