- Creator Backlash: While Eric Saward liked the script, he felt it was poorly directed and that Peri's role in the action was not sufficiently prominent.
- Deleted Scene: A deleted scene shows an extended conversation between the Doctor and Peri on the immobile TARDIS. The Doctor's attempt to fix the chameleon circuit from the previous story is mentioned. Apparently, it continued to malfunction during an offscreen adventure, where the TARDIS materialised as a pyramid on the frozen plains of Yuin 9. Afterward, the Doctor stabilised it back to generating the police box appearance. Peri jokes the TARDIS might end up as Nelson's Column, until the Doctor shouts at her for insulting his workmanship.
- Edited for Syndication: This story, like the rest of Season 22, was produced in forty-five minute episodes, but when sold to other countries such as Australia and America, the episodes were re-edited into four twenty-five-minute episodes. The cliffhangers for parts one and three were the Doctor and Peri arriving on Varos in the TARDIS and the Doctor and Jondar's rescue of Peri and Arreta from the rehabilitators, respectively.
- Throw It In!: Colin Baker ad-libbed the "Perrier Water" gag.
- What Could Have Been:
- The story was first written for the 1982 season, but was repeatedly pushed back and re-written. In its final draft, the story had a number of comedic sequences, most of which wound up being cut, and one of which, the acid bath sequence, was played seriously. The result was that the final story was much darker than originally intended.
- Sil was originally a minor role, while the Governor was the main villain. Eric Saward suggested making him the main villain and the Governor his accomplice.
- Julian Glover, John Hurt, Derek Jacobi, Ian McKellen, and David Warner were considered for the Governor.
- Patrick Stewart was considered for the Chief Officer.
- Jim Broadbent and Paul Darrow were considered for Arak.
- Working Title: Domain and Planet of Fear (the latter being vetoed for being too similar to the previous season's "Planet of Fire").
- You Look Familiar:
Trivia / Doctor Who S22 E2 "Vengeance on Varos"