Tony Robinson singles out this episode as the one in which Baldrick's catchphrase, "I have a cunning plan", was firmly developed. The phrase had featured in previous episodes - it had been used in The Foretelling (1983), and in Born to Be King (1983), Prince Edmund and Baldrick develop it whilst plotting against Dougal McAngus. Robinson recalls that during the filming of this episode, he realised that re-using the word "cunning" could be an effective comedic device and he inserted it into his line "I have a plan" as Baldrick conspires with Edmund to escape from the dungeon.
The actor originally hired to play the role of Piers, one of the peasants who falls victim to the black death during the episode's cold open, fell ill and ended up being unavailable for filming. The role was therefore hastily recast with Howard Lew Lewis, who had played Mr. Applebottom in The Queen of Spain's Beard (1983) and happened to still be available. Despite Lewis wearing the same costume from the previous episode, the writers have said that Piers and Mr. Applebottom are not intended to be the same character.
This episode features a number of scenes filmed on location at Alnwick Castle in Northumberland, the setting for King Richard's castle throughout this series. Due to limitations on budget, only selected actors were filmed on location, including Frank Finlay, who filmed scenes there as the Witchsmeller. A production assistant on the series, Hilary Bevan Jones, recalls that she forgot to pick up Finlay from the location at the end of a shoot and left him behind, until the make-up team found him wandering in the snow in full Witchsmeller costume and brought him back to the hotel.
Despite budgetary limitations, producer John Lloyd's account of this episode was that "it felt more like a huge feature film than a BBC comedy" on account of the construction of a large set for the village scene and the extravagant use of costume, make-up, animals and pyrotechnic stunts.
Although the credits give recognition to William Shakespeare, unlike previous episodes in this series, the script does not contain any direct references to Shakespeare's plays.