<span class="SFPTagline"> From SCIFIPEDIA </span>

The production team started with great aspirations for Doctor Who, Season 20. As somewhat of a milestone, it was thought that this season should in some sense celebrate the show's history. As such, appearances were planned by Omega (who had menaced the Doctor in the 10th anniversary story, "The Three Doctors"), The Mara (from the previous season's "Kinda"), The Black and White Guardians (from season 16), long time friend Brigadier Lethbridge-Stewart and long time arch-enemies the Master and the Daleks.

Additionally, producer John Nathan-Turner had been hoping for the opportunity to do a twentieth anniversary special since 1981. BBC1 controller Alan Hart indulged Nathan-Turner by giving him permission to divert the budget for two of his alotted 28 episodes toward a ninety-minute special, provided that additional funding could be found elsewhere. The Australian Broadcasting Commission (ABC), which had been broadcasting Doctor Who since the 1960s, eventually agreed to a co-production deal which allowed them to fund the remainder of the special.

Great changes were also planned for this season. The production team had long felt that the companion character Nyssa was no longer interesting. They had intended to write her out (instead of Adric) at the end of the previous season, but she had been saved by the protestations of lead actor Peter Davison, who liked the character. But this season, her time was up. She would be written out at the end of the fourth story, "Terminus."

Script Editor Eric Saward had long nursed the idea of having an evil companion who would attempt to assassinate the Doctor. The character, who took shape in the form of Vislor Turlough, would be introduced in the third story, "Mawdryn Undead."

Yet another new companion would be introduced in "The King's Demon's." John Nathan Turner had seen a demonstration of a robot prototype whose movements could be synchronized with pre-recorded speech to appear as if the robot was speaking. The robot's creators offered its services to the Doctor Who team in exchange for funding its further development. Excited about the prospect, the production team had a new character written into the script. However, aware that such props could be problematic, they made the character a shape shifter so human actors could stand in for it whenever necessary. To reflect this, they chose the name Kamelion.

But much of this planning was endangered when the BBC's electrician's union went on strike during the season's production. Fully half of the season's stories could not be completed as scheduled. It was only frantic reschedules later in the year that managed to save the majority of the season. However, Eric Saward's Dalek story, tentatively titled "The Return," was lost.

Season twenty began airing on January 3, 1983. The regular season continued the twice a week weeknight presentation of the previous season. "The Five Doctors" was broadcast on November 25, several months after the end of the regular season (but only two days after the actual anniversary of the show's premier).

• Arc of Infinity (4 episodes)
• Snakedance (4 episodes)
• Mawdryn Undead (4 episodes)
• Terminus (4 episodes)
• Enlightenment (4 episodes)
• The King's Demons (4 episodes)

• The Five Doctors (90-minute special)