This is the first expansion for the Second Edition of 7 Wonders. You will need the second edition base game to be able to play this.
Description from the publisher:
In the dark alleys of your city, gold changes hands, alliances are made and secrets betrayed... Now, your influence extends into the heart of rival cities. But be careful, they won’t be shy to return the favor! In addition to two new Wonders and the option of playing in teams, this expansion offers you a new type of card: Cities cards. Mercenaries, thieves, spies, and diplomats will give a new sense of interaction to your games.
The new edition features a new box with gold leaf; improved layout for better game immersion; two new Wonders designed for the expansion; a booklet that describes the expansion’s new effects, and includes cards originally released as the Cities Anniversary Pack.