Character mistake: After firing Percy and Baldrick, Edmund says to Baldrick that he'll probably go back to shovelling dung in the gutter where Edmund found him. In the pilot episode The Foretelling, Edmund actually met Baldrick when Baldrick was pouring a drink for Edmund.
Plot hole: In 'The Foretelling', it is said that Richard IV reigned for "13 glorious years" with a caption showing 1485-1498. 'The Black Seal' starts on St. Junipers' Day, 1498, but Blackadder spends 12 months locked up with Mad Gerald. So when the Royal Family are finally murdered it is actually 1499.
Plan B: Corporal Punishment - S4-E2
Blackadder: I remember Massingbird's most famous case - the Case of the Bloody Knife. A man was found next to a murdered body. He had the knife in his hand, thirteen witnesses had seen him stab the victim and when the police arrived he said 'I'm glad I killed the bastard.' Massingbird not only got him off, he got hom knighted in the New Year's Honours list, and the relatives of the victim had to pay to get the blood washed out of his jacket.
Trivia: Stephen Fry, who played Lord Wellington, ad-libbed most of his lines.
Question: Many times during the series, Lieutenant is pronounced as 'Left-tenant'. Why?