There are two key ingredients for a successful romcom: writing and casting. Get those right and you have a perky, audience-friendly romance. Knock them out of the park as emphatically as Long Shot does and you have a crowd-pleasing charm bomb of a movie that combines intelligence and a sexual spark to explosively funny ends.

The rapid-fire banter and the screwball pacing; the combination of Charlize Theron as Charlotte Field, US secretary of state and presidential hopeful, and Seth Rogen as her childhood friend, Fred Flarsky, a schlubby unemployed journalist who is recruited to punch up her speeches, makes for one of the more successful romcoms of late. There’s a robustly crude Apatow flavour, certainly, but also a touch of Veep savagery. It calls to mind the underrated Ryan Reynolds vehicle Definitely, Maybe. So sharp is the writing and crackling the chemistry that you barely notice that other elements – the workmanlike, sitcom-style photography, for example – can be rather basic.

But this hardly matters: two of the most immediately likable actors in Hollywood, Theron and Rogen are a joy together. Fred dresses like the result of a thrift store trolley dash; Charlotte is in total control of everything, wardrobe included. But sometimes, it seems, the most unlikely combinations can match.