Population is a game mechanic with which you level up your cities.

Underneath each city is a segmented bar, the number of segments indicates how much population you need for the city to level up. When you gain a population, a segment will turn blue. Once you have accumulated enough population, the bar will reset and increase in length by one segment, and the city will level up, providing you with a small perk.

The dots within the segments indicate how many units that city is currently supporting. You cannot have more units than segments.


An Imperius city, with four population to the next level.

Increasing the total population of cities is essential in establishing a strong economic backbone for your empire and to sustain a proper army for both offensive and defensive operations.

To gain more population for a city a number of things can be done:

Action Population Growth Stars spent Growth to Stars ratio Technology needed
Harvest Fruit 1 2 0.5 Organization
Fishing 1 2 0.5 Fishing
Farm 2 5 0.4 Farming
Mine 2 5 0.4 Mining
Hunt 1 2 0.5 Hunting
Temple (Water, Mountain, Normal) 1 20 0.05 Aquatism, Free spirit and Meditation
Forest Temple 1 15 0.067 Spiritualism
Lumber Hut 1 2 0.5 Forestry
Roads 1 when connecting a city to the capital 2 per road varies Roads
Port 2 10 0.2 Sailing
Sawmill 1 per adjacent Lumber Hut 5 varies Mathematics
Windmill 1 per adjacent Farm 5 varies Construction
Forge 2 per adjacent Mine 5 varies Smithery

Population Upgrades

Here are all the rewards for upgrading a city:

Once a city in your empire reaches level 5 for the first time, you will unlock the Park of Fortune monument.

Negative Population (Anti-Food)

If a city ever loses population (i.e. a city disconnected from the capital, a Nature Bunny crushing a building, destroying a building) and your population bar is empty, a red-colored segment will appear in the population bar. Each red segment removes 1 star from your production. It is not possible to make less than 0 stars per turn. You can still support Units with red segments.

If your bar fills up with red dots, your production for that city will stop completely. Should you continue to lose population, the bar will begin to shrink, and you will no longer be able to support as many units.

If you were to regain the population, you would have to first remove the red segments before creating blue segments again.

NOTE: This is likely a bug, but if you make the bar disappear entirely, it will become impossible to make it reappear.

Ruin Rewards
Battleship, Crab, Explorer, Giant, Population, Population Growth, Stars, Super Unit, Technology
City Upgrades
Border Growth, City Wall, Explorer, Park, Population, Population Growth, Stars, Super Unit, Workshop
Game Mechanics
AI Relationships, Combat, Population, Stars, Technology, Terrain, Unit Skills