Doctor Who And the Rebel's Gamble (1986)

This science fiction game book uses a simplified version of the Doctor Who Role Playing Game. The book contains the rules of the game and some background on the Doctor and his universe. This book uses the sixth Doctor (Colin Baker) whom is accompanied by Perpugilliam 'Peri' Brown and also rejoined by Harry Sullivan (who accompanied the fourth Doctor on some of his television adventures).

From the back of the book:

Something was seriously wrong with history...

And the disappearance of a psychiatrist and his patient from the 20th century was only the beginning. In this plot-your-own Doctor Who adventure, the Doctor and his Companions travel back to America at the time of the Civil War. There, they learn that a time-loose rebel soldier has discovered how the war turned out, and is hard at work making certain that this time around, the South wins!

Doctor Who plot-your-own adventures are a new concept in interactive fiction, combining the detail and depth of a novel with the fast-paced excitement of a role-playing game. As the intrepid Doctor, you make the decisions that determine the course of an adventure. Each decision leads you, step by step, through an unfolding story-plot, where your skill will make the crucial difference between success and failure.