Tunnels &Trolls is the 2nd oldest role-playing game and has been in print since 1976.  This is the 5th edition version that most people remember and used from 1979 to 2006. Like most RPGs you play this with a GM and a group of players.  Play is quick and streamlined and T&T has more emphasis on role-playing and less on charts and reference books. All the rules you need are in this book and there is even a small GM adventure in this book you can use. The other unique aspect of T&T is that it’s one of the few RPGs you can play solitaire. There are well over 50 solo adventures available, including 26 published by Flying Buffalo.