The Population Unit or 
is a fundamental source of production for an empire. Almost all FIDS production is provided at a rate per , and the growth of a population source is immensely valuable to any empire.
Overview[]
Each population unit produces a certain amount of FIDS depending on the planet and system improvements it is placed in. 
production thus scales with the amount of population an empire has. Four major factors affect FIDS rates per population - Planets, Planetary Exploitation, and most Improvements. Because of this, having a large population is important to developing an empire.
Growth[]
- Main article: Food
Growth is calculated per star system. Population requires 
to grow. Exact formula is unknown, but growth seems to depend on food surplus (positive) and number of existing population on a system (negative).
Some observation about growth:
- - despite having growth higher than 200% is the next turn generated only one pop.
- - growth doesn't carry to the next turn. 99% and 50% mean the same - one new pop in 2 turns.
- - growth declines when pop arises, despite system having the same food surplus.
- - for good early growth aim at 10 times or more food surplus per one pop.
- - later on, when building +pop improvements on crowded systems, temporarily change planets' exploitations to food to actually fill new room with pop in decent time.
- - At least one planet per system should have a large source of food to ensure good growth.
Population can decrease 
. This means that to ensure growth, a low tax rate, approval improvements and Exploration and Expansion technologies will be required.
Planets[]
Each planet has a maximum to the amount of population it can sustain.
The habitability class, and size of a Planet, influences its maximum . This is important because resource rates are per - in other words, max population determines the maximum output of a planet.
| Planet type | Tiny  |
Small |
Medium |
Large |
Huge
|
|---|---|---|---|---|---|
| Ocean, Jungle, Terran | 4(14) | 5(14) | 6(13) | 8(14) | 10(16) |
| Tundra, Arid | 3(13) | 4(13) | 5(12) | 7(13) | 8(14) |
| Arctic, Desert | 2(11) | 3(11) | 4(10) | 5(10) | 6(11) |
| Barren, Lava | 1(10) | 2(10) | 3(9) | 4(9) | 4(9) |
| Gas, Asteroid | 1(11) | 2(11) | 3(10) | 3(9) | 4(10) |
There are numerous ways to increase cap on a planet :
- Improved Thermodynamics (tier 3) - Endothermic Structures (+2 Tiny, +1 Small)
- Non-Baryonic Shielding (tier 7) - Psychological Insulation (+1 Planets, +1 Planets with explored moon)
- Personal Fields (tier 8) - Living Habitats (+1 Tier V)
- Sustainable Supercities (tier 11) - Self-Replication Habitats (+2 Planets)
- Horatio's Shared Fields (tier 8, replaces Personal Fields) - Stable Habitats (replaces Living Habitat) (+1 Tier I, II and V)
- Racial trait Crowded Planets (+2 Tiny and Small, +1 Medium)
- Several anomalies add +1 to the planet (Deserted Cities, Hollow Planet, Low Gravity, Friendly Locals, Garden of Eden)
Maxima (including the above improvements, racial trait, one anomaly and an explored moon) are listed on the table above in brackets (#) next to the default value