Ferris Bueller (Matthew Broderick) has complete control over his parents who fawn over his every wish. Today he's managed to wangle a day off by pretending to be ill and he's not going to waste it. He calls up his genuinely friend, Cameron Frye (Alan Ruck), borrows his Dad's Ferrari, picks up his girlfriend Sloane Peterson (Mia Sara) and heads off to the big city.
Meanwhile, the Principal of the school, Ed Rooney (Jeffrey Jones), smells a rat and vows to catch Bueller so that he can finally be brought to justice.
One year after brilliantly studying the relationships between kids in detention with The Breakfast Club, John Hughes turned his attention to the endless possibilities of those that escape it by skiving. Ferris Bueller is the protagonist that we should all hate - his one complaint in life is that his parents bought his sister a car when he only got a computer - but end up loving anyway.
In fact, Ferris has very few likeable qualities. He is disobedient and has a natural hatred for his elders. He encourages others to ignore their illnesses so that he can steal a highly valuable car - all whilst playing truant. All this and turning his nose up at his sister while she struggles for the attention she probably deserves. I know what you're thinking; he sounds damn fun and you wish you'd known him at school.
And, you're right - the whole film is a heap of fun. The comedy aspect is helped by the hapless Rooney (Jones), whom Hughes would later use as a template for the Wet Bandits in the Home Alone franchise. Other than laughing at how spoilt he is, Ferris contributes very little in this department other than causing the chaos around him - especially in the situations he puts Cameron in.
The best thing to do now is take the day off and lie in bed. Tell your spouse/partner/parents that you've got a runny nose and when they're gone pull out the DVD player from under the bed. Watch Ferris, then - and I don't care where you currently are - go to Chicago.