Wealthy New York City playboy Arthur Bach (Dudley Moore) is perpetually drunk and completely rudderless. Dutifully supported by his sharp-tongued and quick-witted butler, Hobson (John Gielgud), Arthur reluctantly prepares to enter into an arranged marriage with heiress Susan Johnson (Jill Eikenberry). When he meets Linda Marolla (Liza Minnelli), a waitress from Queens, he falls head over heels in love, but if he backs out of his engagement with Susan, he may lose his fortune.
Jack Spade (Keenen Ivory Wayans) comes home to the ghetto and finds his brother dead from a gold chain overdose. With the help of his hero, John Slade (Bernie Casey), and a team of washed-up crime fighters, Spade declares vengeance on Mr. Big (John Vernon), the white crime leader responsible for selling gold chains on the streets. But Spade realizes that he must take matters into his own hands to finish the job in this zany spoof of 1970s blaxploitation films.
Teen misfits Gary (Anthony Michael Hall) and Wyatt (Ilan Mitchell-Smith) design their ideal woman on a computer, and a freak electrical accident brings her to life in the form of the lovely, superhuman Lisa (Kelly LeBrock). She outfits Gary and Wyatt in cool clothes, surprises them with a Porsche and helps them stand up to jerks Ian (Robert Downey Jr.) and Max (Robert Rusler). But, all the while, the boys must hide Lisa’s existence from Chet (Bill Paxton), Wyatt’s nightmare of a big brother.