War, what is it good for? Absolutely nothing except for anarchic belly laughs in this subversive Marx Brothers outing in which Rufus T Firefly (Groucho Marx) leads Freedonia into a pointless conflict with a neighbouring state after he's called an upstart. Meanwhile, Chico and Harpo play a pair of spies sent to infiltrate Freedonia's regime. A subversive comedy that bulldozes everything in its path, Duck Soup's satire of war and nationhood may be borderline insane, but that only makes its distrust of pompous politics all the more scathing.

"DELIRIOUS VERBAL BANTER"

Unpredictable, hilarious, and completely deranged. Duck Soup is without doubt the distillation of everything that the Marx Brothers claimed as their own. The film boasts delirious verbal banter, interludes that could have been dreamt up by avant-garde surrealists on the Parisian Left Bank, and a total lack of respect for the rules.

Standout moments include the madcap sequence in which Chico and Harpo drive a lemonade seller to distraction by swapping their hats around, and the amazingly choreographed scene in which the silent Harpo hides from Groucho by pretending to be his reflection in a broken mirror. Every move Groucho makes, Harpo - disguised in similar attire - mimics perfectly.

Released in 1933 Duck Soup ruffled plenty of feathers, with American audiences dismayed by its cynical take on war and international politics at a time when the world was just waking up to the crisis of Nazism. The brothers were unfazed by such negative publicity, though, and were far too certain of the rightness of their cause to be dragged off track by grumbling dissenters. In the words of Groucho himself: "If you can't get a taxi, you can leave in a huff. If that's too soon, you can leave in a minute and a huff." Sheer genius.