Of course, you can always choose "random" and let the fate decide for you, but even so you have to be aware of the fact that each civilization has its advantages, inviting certain strategy of play.
In previous versions of the game, the differences included unique units for each civilization and different starting technologies. In Civilization IV the differences are more drastic, as each nation has a leader(s) with certain character that defines (or being defined by) 2 "traits". Each trait means there are certain buildings that are easier to construct (double production speed) and one "game concept" effect: culture, Great people generation etc.
The full list of traits are as follows: - Aggressive
- Free promotion (Combat I) for all melee and gunpowder units.
- Construct at 1/2 Production Cost: Barracks, Drydocks
- Creative
- Effect: +2 culture per turn per city.
- Construct at 1/2 Production Cost: Colloseum,Theatre
- Expansive
- Effect: +2 health per city
- Construct at 1/2 Production Cost: Granary, Harbor
- Financial
- Effect: +1 commerce on spaces generating 2 or more commerce.
- Construct at 1/2 Production Cost: Bank
- Industrious
- Effect: +50% wonder production.
- Construct at 1/2 Production Cost: Forge
- Organized
- Effect: -50% civic upkeep cost.
- Construct at 1/2 Production Cost: Courthouse, Lighthouse
- Philosophical
- Effect: +100% Great People birth rate.
- Construct at 1/2 Production Cost: University
- Spiritual
- Effect: No anarchy
- Construct at 1/2 Production Cost: Temples