Sins of a Solar Empire is often described as a 4XRTS game, or a game that tried to merge the action and tactics packed gameplay of a Real time strategy game with the deep, complex, empire wide strategy of a 4X turn based game. Its up to debate whether Sins succeeded in this goal, but I think all can agree that of the 4Xs of "explore, expand, exploit, and exterminate", Sins is much more focused on the exterminate than on the other three.
This mod seeks to give more depth to the other 3Xs of the game by adding additional game elements or refining the existing ones to reward players who give more strategic thought to the non-combat side of the game. Combat will still be the center point of the game, but players will find that the non-combat options available will be much more rewarding and will need to put more thought into developing their economies. This mod will also attempt to address some other weaknesses of Vanilla Sins where possible, such as increasing race diversity or improving the AI.
Version 1.1 is a major overhaul of the Diplomacy system, adding embassies, espionage, and improved pact and envoy abilities, as well as Enhanced AI.
Version 1.2 added 8 new colonizeable planets, 8 new artifacts, improved planet exploration, balance and many, many other things.
Version 1.3 added hero units, powerful super capitalships that are limited to one each. More info in readme file.
For more details, see
Link