Regarding Blackadder's cunning plan to become king, Baldrick asks if it is as 'cunning as a fox what used to be Professor of Cunning at Oxford University, but has moved on and is now working for the UN at the high commission of International Cunning planning?'. This is building on a line delivered by a previous Blackadder to his Baldrick in Blackadder Goes Forth: Goodbyeee (1989), involving a plan 'as cunning as fox who's just been appointed Professor of Cunning at Oxford University'
Brian Blessed, Elspet Gray and Robert East were originally going to reprise their roles from The Black Adder (1983). The scene would have been Blackadder and Baldrick arriving at Bosworth field and killing Henry Tudor with the time machine, however the scene was later changed to the battle of Waterloo as Blessed was unable to reprise his role of Richard IV.
Although not correct to the period, black extras can be seen in the Robin Hood and Elizabethan scenes. This is because of a long-running joke between comedians Richard Curtis and Lenny Henry who apparently always complains that he could have been the extra instead.
In the film, the time machine materializes in a space battle. In "Blackadder's Christmas Carol", Ebenezer Blackadder is shown by the Spirit of Christmas, a vision of a distant future, where his distant descendant Grand Admiral Blackadder is a successful, if ruthless, official of a Universe-spanning Empire, with Baldrick as a thong-wearing slave.
The budget for this mini-movie allowed for far more elaborate sets than had been seen since the first series. In particular, the set for "Queenie" Elizabeth I's court - a small room, barely capable of holding 10 people in Black-Adder II (1986) - is a large, richly-decorated space in this film, filled with dozens of courtesans. Queenie's costume is also far more elaborate in this film.
This film includes extensive location shooting, a rarity for a "Blackadder" production. Although the first series (The Black Adder (1983)) did quite a bit of location shooting, the high cost nearly led to the cancellation of further series. After extensive cost-cutting, Black-Adder II (1986) includes the only location shooting in later series/specials: a courting scene in Black-Adder II: Bells (1986), and the end credit sequences, all filmed in a single day at Wilton House, Wiltshire.