Description: Sins of a Solar Empire: Diplomacy is the second expansion pack for Sins of a Solar Empire. Combined with the original and the first expansion pack (Entrenchment) you get Sins of a Solar Empire: Trinity. The first expansion pack added a new defense-based technology tree and starbases, features that had been requested by players to enhance the tactical options for players. Diplomacy is a different animal all together. It is much more subtle. There are no big new structures in it. Instead, it focuses on allowing players to pull strings from behind the scenes. [Stardock]