City
    Cities are a key component of the game. Cities can be founded by the People unit, one of which players start off with at the beginning of each game. Cities are made up of tiles, each of which can have buildings on it.

People
    The People unit allows the player to create a city with 100 initial population. It can move up to five tiles per turn, and can travel only on land. A People unit can be created from a city tile with at least 150 population - 50 will remain on the tile, and 100 will leave to form the unit.

Scout
    The Scout unit is best for exploring nearby land. It can be produced in cities, and costs 50 production points to make. Since the Scout is a non-military unit, these points can come from armories or forges. However, the Scout can participate in combat, and has a strength of 0.5. This makes it a poor choice for main combat, as it is weak compared to other units such as Legions. Since it takes so few production points to be made, and can usually be produced within a few turns, it makes a good choice for an early-game exploration unit. They can also be used to blockade a city from Raider pillaging.
    Scouts can move up to 8 tiles per turn, making them effective at exploration of nearby land territory.

Riverboat
    Riverboats are naval units, and allow the player to explore rivers and lakes. They cost 500 production points to make, and so they will take significantly longer to produce than a Scout; thus they are better suited for production in more developed cities. Like all produced units, they appear in the center of the city when finished producing. Since riverboats can only move on water tiles, if a city's center is not adjacent or diagonal to a water tile, the riverboat will be stuck in the city center.

Legion
    Legions are the main combat unit at the moment. They have 2 base strength, and can move 1 tile per turn. They take 250 production points to make, which make them a good choice to defend cities early on - a city that focuses solely on Barracks can produce a few Legions before any Raiders spawn, which can help with defending a city from being pillaged.

Raider
    Raiders are units with the sole purpose of making the life of your cities and your people much, much harder. They spawn on tiles that are fogged by war (greyed out) and make their way towards your cities. To ensure that you don't get rushed and attacked too early into the game, Raiders can not spawn until a decent number of turns into the game. Each turn after that number of turns, there's a chance that a Raider spawns. The total number of Raider units also caps at a number, and both that number and the spawn chance change with the difficult. (They are both 0 when the difficulty is 0.)
    The main goal of Raiders is to pillage and kill the population of your cities. When Raiders make their way to a city tile, they will begin to kill a portion of the population on that tile each turn. It is crucial that they don't make their way to the center of your city, as you will then be unable to produce more units in that city until the Raider is gone.