Warlord Games offers its Dr. Who Exterminate rules free for the downloading.
A fan of the Doctor Who universe has put together a sourcebook of material for the Third Doctor's extracanonical adventures from novels, audios, comics and the like. The book is designed to go with the Dr. Who role playing game. It looks very professionally done.
Gamers of a certain age probably will have fond memories of Cosmic Encounter, which was first released in 1977. The game has gone through numerous incarnations, currently residing at Fantasy Flight. At the core of the game is the interplay between the various interstellar races. The owner of the Dice Monkey site has created some very nice Dr. Who themed alien races for Cosmic Encounter.
The Twelve Doctors is a fan created card game based on the enormously popular Dr. Who franchise.
From the Board Game Geek Description:
The Twelve Doctors is an unauthorised, non-profit and non-collectable card game set within the immensely popular Doctor Who universe.
Consisting of two balanced 60-card decks, the game pits two players against each other for the fate of the galaxy. One player takes the role of the Doctor in all his regenerations, and his opponent assumes control of his arch enemy, The Master.
The game has an asymmetrical design, with both decks featuring different cards and abilities. The Twelve Doctors is played using a 3-column time-line system, representing the battle for Gallifrey, Earth present and future, and Earth past. Gameplay is quick and bloodthirsty with companions EX-TER-MI-NATED! frequently, and marauders being dropped into black holes, or destroyed by the well-placed use of Venusian Aikido.