Cities of Splendor is a quartet of expansions for use with the Splendor base game, with each expansion being independent in addition to being compatible with one another.
One expansion gives players something new to compete for while playing, something bigger than the nobles who await your interest in the base game.
A second expansion gives you elements to place on cards that represent the cities.
A third expansion has a player board on which you claim special powers and twist the rules if you claim certain cards.
The fourth expansion has new cards with special powers that are shuffled into the three decks of the base game.