Game of Rassilon
The Game of Rassilon was a practice within ancient Gallifreyan history in which members of lesser species were Time Scooped into the Death Zone on Gallifrey to fight for the amusement of the Time Lords. (TV: The Five Doctors) After it was clear they "[played] the game too well", the Daleks and Cybermen were excluded from the blood sport. (PROSE: Dalek Combat Training Manual)
Eventually, Gallifrey moved past its ancient ways, yet President of the High Council Borusa later revived the Game in a plot to achieve immortality. (TV: The Five Doctors) The "Jane Fonda" Iris also once claimed the Second Morbius restarted the Game on one occasion. (PROSE: The Scarlet Empress)