A production city is one tuned to work all the high production tiles it can, with enough farms to support the food demands of its population (2F per pop). You don't build cottages or windmills in a production city. So its _is_ a balance between food and hammers, but it is _not_ a "balanced city", as every tile will either be a mine, a workshop or a farm (or a resource) - so the commerce of the city will be quite low - thus libraries and banks don't make much sense in such a city. A commerce city spams as many coattages a possible, works coast, resources and a very few number of famrs if required to feed cottage+plains tiles. Windmills on the hills if you're stuck with hills. Many grassland is good for this type of city. A GP factory city makes farms + Winmills to make huge excess population and run specialists to make Great People. The more grassland and floddplains the better. City location is very important for Production Cities. They must have a lots of hills, and some grassland, food resources or floodplains. Plains are not so good - as they require 1 extra food (same as a grassland hill) or you farm them and get only 1 hammer from them. The best tiles to see are : heavy hammer resources, floodplains, grassland, food resources and mines. Coast is not too useful - make it a commerce city instead. If a production city has spare food, use engineer specialist to make Great Engineers - then if you don't have a wonder you really need ready to build then make a Super engineer - (3 hammers + 3 beakers) in the city. Buildings - build a forge, and enough health + happiness boosting buildings to keep growing. Build a barracks - this city will make many units in the game. Build a factory and a power plant. if you need the culture to spread the city boundaries build an obelisk - or later use a Theatre - library is too expensive to justify just for the culture. Build a drydock if you have sea access and want a lot of elite ships. Small wonders - Heroic Epic + West Point is traditional for large numbers of elite units. Herioc Epic + Ironworks for just huge amounts of units. Iron works + forbidden palace if you need the palace in that area of your empire. Wonders - if your plan indicates a particular wonder then you'll stand a better chance of winning the race. Spaceship victory - you can loose this race by not getting the right tech's soon enough or not building the part soon enough - so your empire will need a balance of production and commerce city to win. GP factories are optional, but I think evey empire needs some production cities and some commerce cities in its core.