This is the same book as included in the MegaTraveller box set, it was also available for seperate sale.
Abridged from the back of the book:
In less than a minute, the fortunes of the Imperium have turned. An assassin has cut down the emperor and his heirs in one bold strike, throwing the largest interstellar empire in history into chaos. There are many candidates for the empty throne, and without agreement on their qualifications, the worlds of the Imperium are divided in their allegiances. The assassin himself controls three rebellious sectors. The emperor's nephew has assumed the throne. Fleet battles rage throughout the empire. Alien forces, sensing weakness, have crossed the Imperium's borders. Sector after sector falls to the chaos of rebellion.
Traveller sets an ongoing drama of role-playing adventure in this shattered Imperium. Players travel between star systems, taking sides in the rebellion, fighting for their cause while fighting to stay alive. The dangers of space and the dangers of a shattered Imperium provide never-ending excitement in the far future.
The Player's Manual: This book is a basic compilation of Traveller rules and concepts for the individual player. It includes character generation, combat reolution, psionics and tasks (the key to using all of Traveller's rules systems).
Other Traveller Rules Books: This book is part of a three-book set which provides basic rules
The Referee's Manual is a rules reference for the referee.
The Companion Imperial Encyclopedia serves as a basic background reference for use by both the players and referees
Mega Traveller Players' Manual: Intended for all Traveller players. Intermediate complexity. Suitable for some solitaire play. Requires two or more six-sided dice (not included).