- First Appearance: Of the titular pepper pot shaped creatures who would become the Doctor's greatest nemesis.
- Inspiration for the Work: Terry Nation was influenced by the threat of racial extermination by the Nazis and the concerns of advanced warfare, as well as The Time Machine.
- Missing Episode: Averted, but only narrowly so. This story was supposed to be junked, but by sheer luck a BBC employee working in the vault noticed these episodes were marked for destruction and intervened. However, the first episode had to be filmed twice (after it was discovered that talkback from the production gallery had inadvertently been captured on the soundtrack), and the original version does not survive (apart from the cliffhanger, which was used as the reprise for the broadcast episode 2).
- Throw It In!: William Russell improvised the line about the room the crew has just entered likely containing the material they supposedly need to fix the TARDIS, feeling that after so much wandering around, the audience would probably need a reminder of what they were doing in the city in the first place.
- What Could Have Been:
- Originally, the Daleks and the Thals were both confronted by a race of beings from another planet, who revealed that it was their ancestors who had actually fired the neutron missile which had devastated Skaro centuries earlier. Their people had since realised the error of their ways and sought to help both the Daleks and the Thals rebuild their shattered civilisation.
- In the original script, much was made of a forthcoming great rain a periodic meteorological event on Skaro which would reduce the radiation levels enough to permit the Daleks to emerge from their city and confront the Thals.
- The dangers facing Ian, Barbara and the Thals in the mountains originally included mutated spiders and a fiery gas fissure.
- The Doctor and Susan were originally sentenced to be executed in a Sonic chamber.
- The designer originally assigned to this serial was Ridley Scott. However, a problem with Scott's schedule meant that he was replaced by Raymond Cusick, who was thus given the task of realising the Dalek creatures.
- Earlier versions of the Dalek design had rounded bases; the final angular design was chosen because it allowed the option of making the base from separate flat panels, rather than as a single fibreglass casting. They were also supposed to have their gunstick mounted on a ring around the midsection, allowing a 360-degree field of fire, but this proved too expensive to do; the swiveling midsection would later become a permanent staple of the Daleks in "Dalek", roughly 42 years later.
- Cusick wanted the orbs on the casing to be flashing lights whenever they get agitated using a car battery behind the seat. However, this was cut because of budgetary reasons. The flashing lights idea were added on the dome section when the director couldn't tell which Dalek was speaking.
- Working Title: The Survivors and Beyond the Sun.
Trivia / Doctor Who S1 E2 "The Daleks"