Plan B: Corporal Punishment - S4-E2
Continuity mistake: Black Adder shoots the pigeon, and the feathers fly everywhere. One feather lands on Black Adder, just above his ear. In the next shot, the feather has moved up, on the other side of his side-part, towards the top of his head.





Answer: It's not known what Baldrick's first name is. Sod off is a way of telling someone to go away/get lost, so when the kids said, "We know. Sod off, Baldrick," they were essentially telling him to go away.
This has been posted before. Baldrick thinks that's his name. Because he is stupid, he thinks they said his first name. It's a joke.
lionhead