The Upgrade Kit for Mega Civilization contains three packs of civilization advance cards increasing the total number of cards for each civilization advance to 18 cards. I.e. one of each for each player in a game with the maximum player count of 18. Probably never needed for actual play, which is why a lower number of certain cards were included in the original game. However, with the Upgrade Kit, each player can have his or her own deck of buyable cards to look though thereby easing the flow of the game. The Upgrade Kit includes errata cards where necessary.
The three card packs contain:
Pack 1
1x Contents card
6x Calendar
6x Cartography
6x Diplomacy
4x Enlightenment
6x Fundamentalism
6x Law
2x Military
6x Monument
6x Naval Warfare
4x Trade Routes
8x Universal Doctrine
10x Advanced Military
6x Library
Pack 2
1x Contents card
12x Anatomy
9x Cultural Ascendancy
8x Democracy
12x Diaspora
2x Mathematics
2x Mining
2x Monotheism
12x Philosophy
2x Politics
12x Provincial Empire
2x Road Building
1x 5 Victory Points card
Pack 3
1x Contents card
10x Public Works
12x Theology
10x Trade Empire
11x Wonder of the World
1x Explanation card
18x Starting Civilization cards
14x Blanco cards