Čtyři kamarádi plánují svoji první bankovní loupež, ale nic nejde podle plánu, a čím víc se snaží, tím je to horší.

One fine day, at about 10 am, in a suburban house, three men, in their thirties are waiting for a fourth buddy. When he arrives, they plan to hold up the local bank where Séverine, their accomplice, is waiting for them. This could well be the beginning of a thrilling crime story, but these tough men, sporting tattoos, are not what they appear. "On fait comme on dit" is a comedy, and these guys could be descendants of the Keystone Cops. They are dreamers not gangsters. So much is riding on this bank heist, the pressure is intense. This tension creates the most diverse and unexpected obstacles for them...

Dans un pavillon de banlieue, trois hommes, la trentaine passée, attendent un quatrième comparse pour aller braquer la banque du coin, ou se trouve déjà Séverine, leur complice. Ce pourrait être le début d'un polar mais nos amis sont les descendants des Pieds nickelés. Ils vont s'inventer les obstacles les plus inattendus. Tellement rêveurs et si peu gangsters.

Patru amici pun la cale să jefuiască prima lor bancă împreună, dar nimic nu merge conform planului, iar nepriceperea lor nu face decât să înrăutățească situația.