There are fourteen major civilizations in Master of Orion (ten in the base game), each with their own appearance, backstory, personality, and specific racial traits . Up to nine of them may be present in the galaxy during a game.
As no universe is perfect, there are certain racial biases at play.
Name
Homeworld
Planets
Ship Improvements
Diplomacy & Trade
Technology & Special
Other Modifiers
Alkari Flock
Normal Low, High
+25% Travel Speed
+25% Combat Speed
+50% Beam defense
+25% Beam attack
Bulrathi Empire
High, Normal Low
Darlok Cabal
Normal Low, High
Elerian Fiefdoms
Normal Low, High
Mind control from Battleships and larger
Beam Attack: +25%
Beam Defense: +25%
Always see all planets, colonies, and ships
Gnolam League
Low Normal, High
Trade Treaty: +25%
Trade Goods: +100%
Credits from Population: +50%
Human Republic
Normal Low, High
Improved Negotiations
Improved Disposition
Klackon Hive
Normal Low, High
Physics
Cannot choose technology applications
Worker Production: +25%
Scientist Research: -25%
Farmer Food: +50%
Meklar Combine
Normal Low, High
Worker Production: +25%
Food consumption: -50%
Mrrshan Pride
Normal Low, High
Psilon Quanta
Low Normal, High
Physics
Discover all technology applications
Sakkra Brood
Normal Low, High
Worsen Negotiations
Worsen Disposition
Population Growth: +50%
Scientist Research: -25%
Silicoid Crag
All None
Worsen Negotiations
Worsen Disposition
Terran Khanate
Normal Low, High
Trilarian Shoal
Normal Low, High
Travel Speed: +25%
Combat Speed: +25%