The Third Imperium

The Third Imperium was the first setting for Traveller, the Original Traveller Universe (OTU).  Set in a vast expanse of space, there are literally millions of opportunities for adventure, for crews of tramp traders and smugglers to military bridge crews and mercenaries. This setting is an explorer's delight, as there are thousands of different worlds, many different aliens to encounter, a huge number of different spacecraft to battle against, and ancient mysteries to be solved.