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All factions have distinct advantages and disadvantages. They have different society traits, start with different technologies, and sometimes even have oddities such as smaller maximum base sizes. This means that every faction has a different overall playstyle, although some factions are more suited to some playstyles than others. For instance, the Hive is more likely to ICS than the Peacekeepers, because Yang gets free Perimeter Defenses but little energy income, while Lal can get more population per base and may want to take advantage of it.

The game settings can enhance or reduce the advantages and disadvantages of each faction. For instance, disabling Blind Research weakens the aliens of Alien Crossfire because they never have Blind Research, so they lose one of their inherent advantages (Or rather, non-alien players gain the same advantage the aliens already have). Likewise, Svensgaard would prefer a world with massive oceans (essentially more territory for him) and arid terrain (which hurts land factions much more than the sea-based Pirates), while all other factions would probably prefer the opposite.

[edit] The factions

A table comparing all the factions follows. Note that a faction's "preference" is preferred by the AI but a human player can (and, under some circumstances, may want to) use something else. However, the faction's aversion, if any, is always enforced: a player may never choose a faction's aversion. It simply will not show up in the Social Engineering table.

Faction	Leader	Preference	Aversion	Society traits	Free tech	Other
Morgan Industries	Nwabudike Morgan	Free Market	Planned	+1 Economy -1 Support	Industrial Base	+1 commerce; begins with 100 extra energy; -3 hab[1]
The University of Planet	Prokhor Zakharov	Knowledge	Fundamentalist	+2 Research -2 Probe	Information Networks	Free extra starting tech; free Network Node at every base; extra drone every 4 citizens
The Spartan Federation	Corazón Santiago	Power	Wealth	+2 Morale +1 Police -1 Industry	Doctrine: Mobility	Free prototypes; Scout Rover instead of Scout Patrol at start
Gaia's Stepdaughters	Dierdre Skye	Green	Free Market	-1 Morale -1 Police +2 Efficiency +1 Planet	Centauri Ecology	First Mind Worm captured automatically; +1 nutrient in Xenofungus
The Lord's Believers	Miriam Godwinson	Fundamentalist	Knowledge	-2 Research +1 Probe +2 Support -1 Planet	Social Psych	25% attack bonus; no research first 10 turns
The Human Hive	Sheng-ji Yang	Police State	Democratic	+1 Growth +1 Industry -2 Economy	Doctrine: Loyalty	Perimeter Defense at every base; immune to inefficiency[2]
The Peacekeeping Forces	Pravin Lal	Democratic	Police State	-1 Efficiency	Biogenetics	Receives double votes in elections for Planetary Governor and Supreme Leader; +2 hab[1]; extra talent every 4 citizens

The expansion pack, Sid Meier's Alien Crossfire brings seven new factions, which are covered here.

[edit] Footnotes

1. ↑ ^{1.0 1.1} Most factions have "0 hab", meaning it can have up to 7 citizens before requiring a Hab Complex. Morgan has -3, so his maximum is size 4 before Hab Complex, and Lal has +2, meaning his maximum is 9. The Hab Complex always boosts the limit by 7, so afterward the limits are 11 and 16 for Morgan and Lal, respectively. Of course, all limits disappear when a Habitation Dome is built.
2. ↑ Net negative modifiers to efficiency in Social Engineering are ignored, while positive modifiers still take effect. Yang's bases can still suffer from inefficiency.