Mods and modding
What mods are and how you use them in the game
"Mods", which is a shorthand for "Modifications of the game EU2", are created by one or more people from the user community. They are a packaged set of files that modifies the historical behaviour and data in EU2. There are many mods availible spanning very different time periods.
Most of the mods are using the function of EU2 that is called "moddir". This function allows you to start a game using the mods own directory.
If you are interested in a mod, you just have to download the mod (normally a *.zip or an *.exe file). If it's an *.exe file you just run the exe and answer eventual questions about where to install the mod. (The latter often happens when the install of EU2 haven't been notated properly in the Windows Registry.)
If it's not an *.exe file, it's recommended that you first read the Readme.txt file (eventually first doing an unzip of only that file), and check how the install should be done. Normally you just do the unzip into the EU2 main directory and the rest is taken care of (eventually except the placing of the shortcut to the mod).
Sometimes you have to create the mods directory yourself (normally in the main directory).
Well known mods
The Age of Imperialism (1337-1913)
AGCEEP - Alternative Grand Campaign and Event Exchange Project unified.
Aberration - something went wrong, terribly wrong...
Alternative Grand Campaign - new events. Dead; see AGCEEP for its succesor.
Event Exchange Project - new events. Dead; see AGCEEP for its succesor.
Europa Portugalis - Strives for historically accurate AI behavior.
Age of Nationalism - gaming after 1820.
Imperium Francorum Universalis - Charlemagne and this stuff, German mostly.
Interregnum - the premier alternative history mod, also designed with balance and special features for MP play
Modern Day Scenario - abondoned, 1990-2200.
Bocaj's 1453 scenario - good, MP-designed, balanced scenario.
Road to the Power - play as a Pagan, exotic minor and lead it to the latin techgroup.
Wenceslaus II's Age of Europa - An age when Europe ruled its own. Scenarios available starting in 1500, 1550, 1680, 1750, 1775 and 1790.
Introduction to modding
Format of the code examples
Config (*.cfg) files
Country initial setup files
Maps with the IDs of provinces on them