Text from The Game Crafter website.
https://www.thegamecrafter.com/games/civilizations-of-catan

Expansion for Settlers of Catan

Civilizations is an expansion to Settlers of Catan that replaces the building costs cards and provides eight different civilizations to play in their stead. Each player takes a Civilization card, choosing from African, Arabian, Babylonian, Egyptian, European, Indian, Japanese, or Roman.

The European card uses the standard Catan building costs. Each other card requires different resources for each build. Though the resource needs are equally balanced across all civilizations, it influences what starting positions are preferential for each player. As each player needs different resources at different points in the game, trading becomes much more active.

On the roll of a 7, each civilization has a different power. This can shake up the game, adding a layer to the strategy. In addition, since only the Europeans move the robber on a 7, the development cards (and the knights contained therein) become much more important to gameplay.