It may be billed as a Victorian farce, but watching The Magistrate is probably the closest any of us will ever come to seeing a pantomime at the National Theatre. Though lacking in “he’s behind you!”, there seemed much the same mood in the stalls as one remembers from childhood panto outings: a sense that anything might happen on stage, combined with the odd comfort of the plot being familiar and inevitable from the moment the lights go down. A farce is a farce; having seen one, you have kind of seen them all.

The plot of Arthur Wing Pinero’s so-called classic of the genre is, by necessity, terribly complicated and quite simple all at once. Mr. Poskett, a London magistrate, has married a widow who lied to him during their engagement, taking five years off her age to make herself seem more attractive. This has also forced her to take five years from the age of her child, a 19-year-old man whom everyone (including himself) believes to be a 14-year-old boy. Mad, but simple. Naturally, though, everything grows far more complicated with the arrival of the child’s godfather, whom Mrs. Poskett fears will give her away to her husband – and so the game begins. It is probably some years since there was last a play at the National where so many people hid behind furnishings.

This revival of The Magistrate has received most press attention for the casting of John Lithgow as the long-suffering magistrate, who brings great humour and warmth to the character. Meanwhile, Nancy Carroll, as his wife, makes her first return to the National since her Olivier-winning performance in After the Dance. It is simply a joy to see her back, and in such a different part; Carroll’s timing and energy are spectacular, and she steals the show. The whole cast are strong, but particularly notable alongside Carroll is Joshua McGuire as the young – but not as young as he thinks – Cis Farringdon. McGuire is hilarious and frankly rather creepy as the boy-adult, some kind of horrible, gambling, reversed Peter Pan in an Eton jacket, who longs for adulthood but has not been allowed to grow up.

The show is at times a spectacle more than a play, with recurrent musical numbers from singing dandies, reams of physical comedy and a slightly overblown set rising ominously from the centre of the stage. There have been some suggestions that this suggests a lack of faith in the script, which is not entirely unfair; it has certainly aged, and not always well. Nonetheless, the central conceit, though overworked, is a relatively funny one, and the entire thing is performed with such gusto that it would be difficult not to be won over. It is a Christmas show – silly and frivolous and, above all, fun.

The sense of enjoyment on stage is infectious, with the performers playing jokes up, wringing them out for yet more laughs. All this certainly catches you up in the thing, though it does get a little tiresome towards the end of the first act. Ultimately, The Magistrate is simply a piece of fluff, which is very enjoyable, in spite of suffering from the problem that plagues many farces: the creeping feeling, at times, that the cast are having more fun than the audience.

The Magistrate runs at the National Theatre until 10 February 2013. For more information and tickets, see the National Theatre website.