There are jokes for all ages in the original French, and I hope the translations provide the same mixture. Some jokes are simple, aimed at eight-year-olds. In the latest book, Asterix and Obelix all at Sea, it was at last possible to work in that hoary old gag "The galley slaves are revolting," so that an irate Caesar could tell the trembling admiral who imparts this news, "And so are you."
Some run to extended literary references, for older children and adults. In Le Cadeau de César there is a whole page where Asterix, defending the local innkeeper, slips into the character of Cyrano de Bergerac as he fights a duel with a Roman while composing a ballade. Quotations from Rostand, Cyrano's creator, come thick and fast.
The translation replaces them with probably the most famous sword fight in English literature, Hamlet and Laertes, and suitable Shakespearian quotations: the innkeeper's wife begins by advising her husband, "Act with disdain!", whereupon the belligerent Roman can point out, accurately, "I am more an antique Roman than a Dane," thus launching the literary sequence
Read the rest of this lovely piece by Anthea Bell, who, with Derek Hockridge, translated all 30 Asterix books.