This setting correspond to the "Lucky Nation" setting in the option screen of the new game menu. There are many more settings you can change here, rather than digging through the configuration file.

Available Options

Settings for Lucky Nations can be Historical, Random and None, giving rather strong bonuses to 8 selected AI nations, 8 random nation or no nations respectively.

Historical nations are (Source and bonuses):

• Castile (before year 1700 and Spain does not exist) / Spain (before year 1700 and Castile does not exist)
• Ottomans (before year 1700)
• Muscovy (if Russia does not exist) / Russia
• England (if Great Britain does not exist) / Great Britain
• France
• Austria
• Prussia (after year 1700)
• Netherlands (after becoming a nation)
• Portugal (before year 1700)
• Poland (if Commonwealth does not exist)
• Brandenburg (before year 1700)
• Sweden (before year 1700)
• Commonwealth (before year 1700)

The other settings that may interest you:

• Bonuses: Give various bonuses to the Player, to the AI or None
• AI Difficulty: Change how the AI react to the player's action. Easy are less harsh than with other AI, Hard is harsher than with other AI

What do they do?

Player Bonuses:

• +50% Manpower
• -3 Unrest
• +50% Force limit (Land an naval)
• -33% Regiment and Ship costs
• -2% interests per annum
• +10% Improve Relations
• +2 Diplomatic Reputation
• +1 Diplomatic Relations
• +1 Advisor
• +1 Free Generals
• -25% Aggressive Expansion
• -0.05 War Exhaustion per Month
• -25% Coring Costs