Pocket Empires is one of the more interesting expansion sets for Traveller version 4. Basically, it provides the rules for players to set up and run their own mini-empires or states within the larger game. It also provides a vehicle for the GM to use to create a back-story for any small states he wishes to establish within the larger galaxy. It's particularly useful if you are hypothesizing an area of "balkanization" within one of the regions of space, which is usually the case immediately outside the boundaries of the Empire. Rules are provided for establishing an empire, conducting "actions" in that empire, improving technology and infrastructure, political interactions, and how to play the Empire within an ongoing campaign as another type of "player." The rules are dense, complex, and at times very difficult to figure out, but generally reward the diligent reader. Personally, I enjoy the concept but think it would be hard to fully incorporate into a campaign as an on-going event -- much better to use it to establish the background of one or more of your minor states. Given the difficulty of the rules, I would normally rate this one about a three, but because I'm fascinated by the ideas presented (many of which are truly creative), I'll take it up to a four.
[4 of 5 Stars!]